Clinical outcomes of nonsurgical root canal treatment using C-Root SP combined with different obturation techniques in older patients: a randomized controlled clinical trial

Clinical outcomes of nonsurgical root canal treatment using C-Root SP combined with different obturation techniques in older patients: a randomized controlled clinical trial | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Clinical outcomes of nonsurgical root canal treatment using C-Root SP combined with different obturation techniques in older patients: a randomized controlled clinical trial Liping Dong, Jianshe Li, Peng Xue, Suixin Hu, Chen Xu, Lin Wang, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5548977/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 15 May, 2025 Read the published version in BMC Oral Health → Version 1 posted 3 You are reading this latest preprint version Abstract Background To evaluate the clinical efficacy and outcomes of C-Root SP bioceramic-based sealers combined with different obturation techniques in nonsurgical root canal treatment for older patients. Methods This prospective, single-center, single-blind, parallel, randomized clinical trial included 240 patients aged ≥60 years. Patients were randomly divided into fourtreatment groups. Group A: C-Root SP combined with single-cone (SC); Group B: C-Root SP combined with warm vertical compaction (WVC); Group C: C-Root SP combined with cold lateral condensation (CLC); Group D: iRoot SP combined with SC (Control). All teeth were subjected to root canal filling using the corresponding methods 7–10 days after root canal preparation and medication. The duration of obturation was recorded. Periapical radiographs were obtained immediately after obturation to determine the length of root canal filling, and postoperative pain on days 1, 2, and 7 was documented. The treatment outcomes based on clinical signs and symptoms as well as periapical index (PAI) were analyzed at 1 year postoperatively. Results Groups A and D exhibited significantly higher filling efficiency than groups B and C ( P 0.05). Postoperative pain decreased over time in all groups, with group A showing significantly lower pain rates on day 1 than the other groups ( P < 0.05). After 1 year, all groups exhibited considerable reductions in the PAI scores, with success rates ranging from 91.23% to 94.83%; however, no significant differences were observed between them ( P > 0.05). Conclusions C-Root SP combined with different obturation techniques yielded similar outcomes to iRoot SP combined with the SC technique in terms of filling length, success rate, and changes in PAI scores. The SC technique demonstrated significant advantages in terms of clinical efficiency and may reduce early postoperative pain when combined with C-Root SP. Trial registration The study was retrospectively registered in chictr.org.cn with the identifier: ChiCTR2400092580 on 11/19/2024. Bioceramic-based sealers clinical trial endodontic outcomes obturation technique postoperative pain Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Background Although the clinical demand for endodontic therapy is increasing among older individuals, they are more likely to undergo tooth extraction than receive periodontal and endodontic treatment and restoration [ 1 ]. Because of the lack of appropriate prevention and maintenance, along with other factors such as low salivary flow, a soft diet with high carbohydrates, and systemic diseases, older patients often present with extensive periapical infection, combined with periodontal destruction, substantial tooth defect, and root caries that would affect periapical lesion healing after nonsurgical root canal treatment (NSRCT) and subsequent tooth rehabilitation [ 2 – 4 ]. Furthermore, increased canal calcification with aging poses challenges in diagnosis as well as in root canal cleaning, shaping, and obturation [ 5 ]. These factors, in combination with anatomical complexities, may prolong the operation duration and cause postoperative pain and fatigue in the maxillofacial joints and muscles, affecting the patient’s acceptance of the treatment [ 6 ]. Moreover, systemic disorders may contribute to the safe and successful completion of NSRCT, whereas increased patient age does not decrease its success or survival rates [ 5 ]. Therefore, aging and its associated systemic disorders do not preclude endodontic treatment in older individuals [ 2 ]. Adequate root canal instrumentation, irrigation, and medication are essential for eliminating endodontic pathogens [ 7 ], and three-dimensional obturation is crucial for preventing root canal re-infection by sealing in residual pathogens and blocking infiltration from apical tissues [ 8 ]. Thus, hermetic sealing of the root canal system is one of the preconditions to ensure successful NSRCT [ 9 , 10 ]. Root canal sealers are used to enhance sealing ability by filling any voids and irregularities between the root canal wall and gutta-percha [ 11 ]. Multiple root canal sealers have been used in clinical settings in combination with different obturation techniques [ 12 , 13 ]. Bioactive properties of bioceramic-based sealers can promote periapical healing and facilitate dentine mineralization. The excellent flowability of this material, high alkaline pH, and less cytotoxicity are beneficial to canal sealing, microbial elimination, hydroxyapatite formation, and subsequent periapical tissue healing [ 14 – 16 ]. Among them, a novel bioceramic-based sealer, C-Root SP (C-root Dental Medical Devices Co. Ltd. Beijing, China), has recently been developed using a strontium silicate–based setting system. Strontium is a trace element in bone that can increase the expression of angiogenic factors in cells, thereby stimulating angiogenesis and promoting bone tissue repair [ 17 ]. Animal experiments have confirmed that strontium can substitute calcium in bioactive materials to stimulate the proliferation, osteogenesis, and angiogenesis of bone marrow stromal cells without exerting adverse local or systemic effects [ 18 , 19 ]. Furthermore, strontium ions share intracellular transport pathways with calcium, imparting them with a strong affinity for binding to the bone matrix. Strontium can reduce osteoclast activity and bone resorption in vitro [ 20 ], and it exerts immunomodulatory effects and radiopacity [ 21 , 22 ]. Multiple in vitro studies have reported that C-Root SP exhibits high biocompatibility, biological activity, and low cytotoxicity in terms of cell proliferation. It also exhibits antibacterial activity against Enterococcus faecalis [ 23 ], superior osteogenic potential compared with AH-Plus [ 24 – 26 ], and reasonable marginal adaptation [ 27 ], making it a promising alternative for root canal obturation. Although C-Root SP has been in the market for > 4 years, well-controlled clinical studies on its clinical outcomes in combination with different obturation techniques are limited. This study aimed to evaluate the clinical efficacy and outcomes of C-Root SP in combination with the single-cone (SC) technique, warm vertical compaction (WVC) technique, and cold lateral condensation (CLC) technique in older patients requiring root canal therapy. iRoot SP (Innovative BioCeramix Inc., Vancouver, Canada), a calcium silicate–based sealer combined with the SC, was used as a control. Table 1 lists the composition and lot numbers of these two premixed bioceramic-based sealers [ 25 , 26 ]. The null hypothesis of this study is that there is no significant difference in operation duration, postoperative pain response, obturation length, and 1-year success rate between C-Root SP combined with different obturation techniques and iRoot SP combined with SC in older patients. Table 1 Composition of the premixed bioceramic-based sealers Sealers Manufacturer Lot number Composition C-Root SP C-root Dental Medical Devices Co. Ltd. Beijing, China 20230403 Strontium silicate, calcium phosphate, calcium hydroxide, zirconium dioxide, fillers and thickening agents iRoot SP Innovative BioCeramix Inc., Vancouver, Canada 23001SP Tricalcium silicates, dicalcium silicates, calcium phosphate monobasic, calcium hydroxide, zirconium oxide, fillers, and thickening agents Materials and methods Participant enrollment This prospective, single-center, single-blind, parallel, randomized clinical trial was conducted in accordance with the Consolidated Standards of Reporting Trials (CONSORT, 2010) [ 28 ] and ethical principles of the Declaration of Helsinki. The study was approved by the Ethics Committee of the Chinese PLA General Hospital (No. S2023-141-01) and was retrospectively registered at the Chinese Clinical Trial Registry (ChiCTR2400092580; date of registration: November 19, 2024). Patients who required NSRCT were enrolled after obtaining informed consent. All patients were informed of the benefits and risks and required follow-up assessments. They were consecutively treated between January and May 2023. Follow-up assessments were performed at least 1 year postoperatively. The flow of participants throughout the study is illustrated in Fig. 1 . The inclusion and exclusion criteria were as follows: Inclusion criteria: Patients aged ≥ 60 years at recruitment. Patients classified according to the American Society of Anesthesiologists (ASA) physical status as ASA I and ASA II. Patients with no known allergies to any material used in the study. Patients diagnosed with pulp necrosis and those with radiographic evidence of apical periodontitis (< 5 mm in diameter), including symptomatic apical periodontitis, asymptomatic apical periodontitis, and chronic apical abscess. Periodontally healthy patients or those with a pocket depth ≤ 4 mm. Patients with tooth mobility limited to grade 0 or 1. For a participant with multiple teeth eligible for the study, only one tooth was randomly selected. Exclusion criteria: Patients with severe systemic diseases, allergy to local anesthetic drugs or multiple drugs, and other absolute contraindications for the treatment. Patients with malignant tumors and taking oral or injected bisphosphate drugs. Patients with extreme fear and psychological disorders that make understanding and cooperation during treatment difficult. Patients with grade 2 or 3 affected tooth mobility or periodontal–endodontic lesions. Patients who underwent endodontic treatment (completed or not), with immature roots, with internal or external root resorption, with root fracture, or with perforation in the affected teeth. Patients with excessive tension in the orbicularis oris muscle and a mouth opening of less than three transverse fingers, making it highly difficult to accurately utilize the required tools in the mouth. Sample size determination The minimum estimated sample size was calculated using the G * Power 3.1 software (Heinrich Heine, University of Düsseldorf, Düsseldorf, Germany) based on previous research data [ 29 , 30 ]. In the calculation for the similarity trial, an equivalence limit of 0.5, standard deviation of 0.73, type I error of 0.05, and power test of 0.90 were used. The sample size was increased by 20% to compensate for dropouts. Finally, 60 teeth/patients were included in each experimental condition. Randomization The patients were allocated to four groups according to two bioceramic-based sealers, C-Root SP and iRoot SP, combined three different obturation techniques using a randomized block design with blocks of 60 patients/teeth each. The group allocation was concealed using a predetermined computer-generated randomization list. The number of tables was prepared separately for three experimental groups, namely, group A (C-Root SP combined with the SC technique), group B (C-Root SP combined with the WVC technique), and group C (C-Root SP combined with the CLC technique), and a control group, namely, group D (iRoot SP combined with the SC technique). Table 1 presents the demographic characteristics of the study population and the distribution of treated teeth according to group. Because the present study was an interventional study, clinicians were not blinded to the procedures being performed. Patients were not informed about the treatment (control or experimental) to which they were allocated. Root canal preparation techniques After a thorough clinical and radiographic evaluation based on the inclusion/exclusion criteria, teeth that met the inclusion criteria were treated in two visits. All teeth were isolated using a rubber dam during root canal treatment. The procedures were performed using a microscope (OPMI Sensera; Carl Zeiss, Germany). The working length (WL) was determined using an apex locator (Raypex 6, VDW GmbH, Germany) and validated radiographically to be 1 mm less than the radiographic apex. For each group, apical preparation was performed using ISO stainless steel hand files (size #10–15, K-reamers, MANI, Japan), beginning with the selection of the first file to bind at the WL. Subsequently, rotary files (ProTaper Next, Dentsply Maillefer, Switzerland) with an endodontic motor (X­Smart Plus, Dentsply Maillefer, Switzerland) were used for mechanical preparation according to the manufacturer’s recommendations (speed: 200 rpm; torque: 2 Ncm). In the presence of EDTA gel, the rotary files were inserted into the canal up to the full WL in the following sequence: X1 (size: #17; taper: 0.04), X2 (size: #25; taper: 0.06), and X3 (size: #30; taper: 0.07). The final instrumentation file was set three sizes larger than the first file used to improve periodontitis healing [ 7 ]. The canals of all groups were extensively irrigated using a 2.5% NaOCl root canal irrigant (5 mL for 1 min), and a disposable plastic syringe equipped with a side-vented needle (0.4 × 25RW, Sungshim, Korea) was used to reach 1 mm short of the WL. An equal volume of irrigant was administered to each tooth (5 mL applied before instrumentation, 5 mL between files, and a final 5 mL flush following root canal instrumentation). Subsequently, the canals were dried using sterile paper points (Dayading Medical Appliance Co., China). The access cavity was filled with a sterile cotton pellet and temporary filling material (Coltosol F, Coltene/Whaledent, Switzerland), and a calcium hydroxide–based dressing (ApexCal, Ivoclar Vivadent, Germany) was placed in the root canals [ 31 ]. Obturation techniques After 7–10 days, the gutta-percha (GP) master cone was selected and trimmed using a blade to ensure a snug fit in the apical root canal, and it was confirmed using a periapical radiograph (eXpert DC, Gendex Dental Systems, USA) before obturation. Similarly, all obturation procedures were performed under rubber dam isolation. The teeth in groups A and D were filled with bioceramic-based sealers C-Root SP and iRoot SP, respectively, by injecting the sealer into the coronal third of each canal. A size 25 Lentulo spiral (Paste Carriers, MANI, Japan) coated with additional sealer was introduced 3 mm short of the WL at 300 rpm. Subsequently, a 0.06 taper GP (Dayading Medical Appliance Co., China) was dipped in the corresponding bioceramic-based sealer and introduced into the canal to the WL. A heated plugger (Alpha unit, B&L Biotech USA Inc., USA) was used to sear the GP point at each orifice. The teeth in group B were filled with 0.06 taper GP (Dayading Medical Appliance Co., China), and C-Root SP was introduced using the master cone. A heated plugger size of 30/.04, 35/.04, or 40/.04 (Alpha unit, B&L Biotech USA Inc, USA) was inserted 3–5 mm short of the WL, and the remaining canal space was backfilled with additional sealer and thermoplasticized GP using the beta unit (B&L Biotech USA, Inc., USA). For group C, the root canals were obturated using a 0.06 taper GP cone (Dayading Medical Appliance Co., China), which was selected based on the master apical file. The cone was lightly coated with C-Root SP and placed into the canal up to the WL. Lateral compaction was performed using finger spreaders (MANI, Japan) with a size of 25. The excess filling material was removed using a heated instrument. For each group, the time from the introduction of the root canal sealer to the completion of a single obturation was recorded, and the coronal access cavities were filled with glass ionomer cement (Fuji IX, GC America, USA) for temporary restoration. The final direct resin restoration or indirect ceramic restoration was performed on the next visit after 7–10 days, according to the European Society of Endodontology position statement [ 32 ]. Postoperative radiographic evaluations The obturation length was classified into “deficient” (> 2 mm from the radiographic apex), “proper” (0–2 mm from the radiographic apex), or “overextension” (beyond the radiographic apex) [ 33 ]. Radiographic evaluations were conducted by two independent, blinded, and experienced endodontists who were trained and calibrated using 150 radiographs unrelated to this study. In cases of disagreement in the assessment of the results, discussions were held until a consensus was reached. Evaluation of postoperative pain The numeric rating scale (NRS) was used for postoperative pain assessment [ 9 ]. This scale encompasses the following grades according to pain severity: 0, no pain; 1–3, mild pain; 4–6, moderate pain; and 7–10, severe pain. On days 1, 2, and 7 after treatment, patients were asked to rate their pain level from 0 to 10. In addition, they were reminded to note the number of analgesics they used when necessary. They were contacted via telephone on day 7 to ask about postoperative pain and analgesic intake. Follow-up evaluation of the treatment outcome Endodontic treatments were considered failure if pain and/or swelling and/or sinus tract were present. Radiographically, if a pre-existing lesion increased in size or remained the same, the treatment was considered a failure [ 9 ]. Periapical radiographs were obtained preoperatively, postoperatively, and at 1-year follow-up. Lesions were reclassified according to the periapical index (PAI) using the following scores [ 34 , 35 ]: 1, normal periapical structures; 2, small changes in bone structure; 3, changes in bone structure with some mineral loss; 4, lesions with well-defined radiolucent areas; and 5, severe lesions with exacerbating features. Two blinded, independent, and calibrated examiners (C.X. and L.W.) assessed the radiographs, and each endodontically treated tooth was assigned the highest score recorded for any of its roots. The treated roots were categorized as follows [ 13 , 36 ]: 1. Healed: Teeth that are functional, symptom-free, and exhibit no radiographic periapical lesions, with a PAI score of 1 or 2. 2. Healing: Symptom-free teeth that function well, show a reduction in the size of radiographic periapical lesions, and have a PAI score that has decreased from baseline but remains above 2. 3. Not healed: Nonfunctional teeth that have symptoms with or without radiographic periapical lesions or asymptomatic teeth with unchanged, newly developed, or enlarged radiographic periapical lesions. These teeth exhibited PAI score comparable to or worse than the baseline. In this clinical evaluation, “success” was defined as belonging to the healed and healing categories, whereas “failure” referred to teeth that were not healed. In cases of disagreement regarding radiographic and/or clinical evaluations, discussions were held until consensus was reached. Examples of each outcome category among the four groups are presented in Figs. 2 – 5 . Statistical analysis All statistical analyses were performed using IBM SPSS Statistics for Windows (version 26.0, IBM Corp. Released 2019). Continuous variables were expressed as means ± standard deviations (M ± SD), and categorical variables were expressed as frequencies with percentages. Normality diagnostic plots and tests were used to test data normality. For the comparisons of the means among the four groups, a two-way analysis of variance was employed for normally distributed data and the Kruskal–Wallis test for non-normally distributed data. Pearson’s chi­squared test or Fisher’s exact test was used for categorical variables to evaluate the group differences. Intra­ and interobserver agreements were examined using weighted kappa analysis. To assess differences in postoperative pain among the four groups according to the NRS scores, the nonparametric Mann–Whitney U test was used to test the hypothesis that the pain difference among the four groups is not significant. The difference in postoperative pain scores within each treatment group at different time points was assessed using the nonparametric Friedman test. Given the substantial differences identified in the Friedman analysis, Dunn’s test with Bonferroni correction was used for pairwise comparisons of time points within the groups [ 37 ]. Data from the PAI score change were analyzed using the Mann–Whitney U test for equivalence via two one-sided tests [ 38 ], as the hypothesis tested was that the two techniques were equivalent. To assess changes in periapical status, the data were subjected to both per-protocol and intention-to-treat (ITT) analyses. In the case of ITT, the PAI at baseline was repeated for the final evaluation of patients who did not attend their follow-up appointments [ 7 ]. A P ­value of 0.05 was considered statistically significant in all analyses. Results Demographics, tooth position distribution, and root canal quantitative information According to the demographic characteristics of the participants, no significant differences were observed in age ( F = 0.094, P = 0.963) and gender ( χ 2 = 0.133, P = 0.988) among the groups. The positional distribution of the included teeth was similar ( χ 2 = 0.227, P = 1.000). Furthermore, no significant difference was observed in the number of root canals in each group ( χ 2 = 0.294, P = 1.000) (Table 2 ). Therefore, the potential impact of these factors can be ignored. Table 2 demographic features of the population and the distribution of treated teeth in each group A B C D Total p -value Sample size 60 60 60 60 240 Mean age (year) 68.97 ± 7.17 68.27 ± 7.75 68.53 ± 8.05 68.47 ± 6.78 68.56 ± 7.41 0.963 Gender [n] (%) 0.988 Male 29 (48.33) 30 (50.00) 31 (51.67) 30 (50.00) 120 (50.00) Female 31 (51.67) 30 (50.00) 29 (48.33) 30 (50.00) 120 (50.00) Location (number of root canals) 1.000 Anterior 20 (20) 19 (19) 19 (19) 20 (20) 78 (78) Premolar 19 (27) 21 (24) 20 (27) 19 (24) 79 (102) Molar 21 (64) 20 (56) 21 (63) 21 (63) 83 (246) Note: group A (C-R combined with SC), group B (C-R combined with WVC), group C (C-R combined with CLC) and group D (i-R combined with SC); C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique; p = significance value using chi-square test Comparison of duration and length of obturation Comparison of the obturation duration of each group showed that the filling efficiencies of groups A and D were significantly higher than those of groups B and C ( F = 71.823, P < 0.001); however, no significant difference was observed between the latter two groups. Furthermore, the use of different root canal sealers in the same obturation technique did not affect the filling duration. All obturated teeth were included in the analysis because of the absence of severely undere-xtended or over-extended obturations (> 2 mm). A comparison of the filling length in each group showed that the proper filling rates were higher in group A than in the other three groups. The overfilling rates of the groups were as follows: group A (3.33%) < group D (5.00%) < group C (6.67%) < group B (8.33%). The underfilling rates in groups B, C, and D were higher than those in group A, but the difference was not significant ( F = 2.318, P = 0.907) (Table 3 ). Table 3 Statistics of operation time and quality of root canal filling in each group A(n = 60) B (n = 60) C(n = 60) D (n = 60) Total (n = 240) p -value Filling time(second) 61.08 ± 12.38 81.07 ± 10.82 ① 87.12 ± 13.70 ① 61.98 ± 11.39 ②③ 72.81 ± 16.66 < 0.001 Quality of root canal filling [n] (%) 0.907 Proper 57 (95.00) 53 (88.33) 54 (90.00) 55 (91.67) 219 (91.25) Overextension 2 (3.33) 5 (8.33) 4 (6.67) 3 (5.00) 14 (5.83) Deficient 1 (1.67) 2 (3.33) 2 (3.33) 2 (3.33) 7 (2.92) Note: group A (C-R combined with SC), group B (C-R combined with WVC), group C (C-R combined with CLC) and group D (i-R combined with SC); C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique; p = significance value using chi-square test; ①Compared with group A, p <0.05; ②Compared with group B, p <0.05; ③Compared with group C, p <0.05 Comparison of postoperative pain after obturation The NRS scores of each group on days 1, 2, and 7 after the operation are presented in Table 4 . The postoperative rate and degree of pain in each group decreased with time. No severe pain on days 1, 2, and 7 as well as moderate pain on days 2 and 7 were reported in any group. In addition, group A experienced no mild pain on day 7. The postoperative rate of pain (mild and moderate pain) in the groups on day 1 after obturation is as follows: group A (11.67%) < group D (28.33%) < group B (31.67%) < group C (33.33%). The postoperative pain rate in group A significantly differed from those in groups B, C, and D ( χ 2 = 9.19, P = 0.027). No significant difference was observed between the four groups in terms of postoperative pain on days 2 ( χ 2 = 6.565, P = 0.084) and 7 ( F = 2.027, P = 0.904). Table 4 Severity and percentage of postoperative pain in each group at various time­points (n;%) A(n = 60) B (n = 60) C(n = 60) D (n = 60) p -value Days 1 Mild pain 7 (11.67) 18 (30.00) 18 (30.00) 15 (25.00) Moderate pain - 1 (1.67) 2 (3.33) 2 (3.33) Total 7 (11.67) 19 (31.67) ① 20 (33.33) ① 17 (28.33) ① 0.027 Days 2 Mild pain 2 (3.33) 10 (16.67) 8 (13.33) 8 (13.33) Total 2 (3.33) 10 (16.67) 8 (13.33) 8 (13.33) 0.084 Days 7 Mild pain - 1 (1.67) 2 (3.33) 1 (1.67) Total - 1 (1.67) 2 (3.33) 1 (1.67) 0.904 Note: group A (C-R combined with SC), group B (C-R combined with WVC), group C (C-R combined with CLC) and group D (i-R combined with SC); C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique; p = significance value using chi-square test; ①Compared with group A, p <0.05; Severe pain on days 1, 2, 7 and moderate pain on days 2, 7 was not included in the table because no case was observed. Comparison of obturation efficacy after 1 year Loss of follow-up and the results of changes in PAI scores 1 year later are presented in Table 5 . The follow-up loss rates were 5.00% for Group A, 6.67% for Group B, 5.00% for Group C, and 3.33% for Group D. No significant differences were observed between the groups ( F = 0.818, P = 0.976). Similar average PAI scores were observed across all groups, regardless of whether the per-protocol or ITT analysis was used ( P = 0.988 and P = 0.986, respectively). All treatment approaches effectively reduced the PAI scores 1 year after treatment ( P < 0.001 for all analyses). In general, the PAI score at baseline ranging from 2.93 to 3.00 was reduced to 1.89 to 2.10 after 1 year of follow-up. Finally, the success rates for all groups after 1 year were in the following order: group D (94.83%) > group A (92.98%) > B group (92.85%) > C group (91.23%); however, no significant differences were observed between the groups ( F = 0.680, P = 0.892). Table 5 the efficacy of root canal filling in each group after 1 year A B C D Total Row p -value Lost follow-up for 1 year [n] (%) 3 (5.00) 4 (6.67) 3 (5.00) 2 (3.33) 12 (5.00) 0.976 Per-protocol analyses Baseline PAI 2.96 ± 1.15 3.00 ± 0.97 2.93 ± 0.98 2.97 ± 0.97 2.96 ± 1.02 0.988 1-year PAI 1.89 ± 1.01 2.09 ± 0.96 2.04 ± 1.00 1.98 ± 0.78 2.00 ± 0.94 0.726 Column p -value < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 - Intention to treat analyses Baseline PAI 2.93 ± 1.13 2.95 ± 1.00 2.95 ± 0.98 3.00 ± 0.99 2.96 ± 1.02 0.986 1-year PAI 1.92 ± 1.00 2.10 ± 0.97 2.10 ± 1.04 2.05 ± 0.87 2.04 ± 0.97 0.698 Column p -value < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 - Success [n] (%) 53 (92.98) 52 (92.85) 52 (91.23) 55 (94.83) 212 (92.98) 0.892 Note: group A (C-R combined with SC), group B (C-R combined with WVC), group C (C-R combined with CLC) and group D (i-R combined with SC); C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique; p = significance value using chi-square test Discussion Various techniques for root canal obturation have been proposed, including SC, lateral condensation, and vertical compaction, and each has its advantages and disadvantages. CLC is widely used because of its low cost and simplicity; however, it lacks adaptability in irregular areas within root canal systems [ 39 ], and excessive lateral pressure may lead to root wall damage and fracture [ 40 ]. WVC has been recognized as the “gold standard” for canal obturation [ 41 , 42 ]. Its good three-dimensional adaptability and filling uniformity allow the GP to flow to the irregular areas of the root canal space upon heating and pressing. However, this technique has relatively high technical sensitivity and may cause micro-leakage when microgaps occur in the root canal and the irregular apical foramen, thereby leading to the retention of chemicals and microorganisms [ 43 ]. The SC technique, a simple and time-saving procedure, has been frequently used by general practitioners owing to the development of bioceramic-based sealers, which possess better fluidity and do not shrink during the setting phase to reduce pore formation [ 44 , 45 ]. Evidently, the operating efficiency of SC was significantly higher than those of WVC and CLC, regardless of the selected bioceramic-based sealers. Therefore, the null hypothesis of no significant difference in the filling duration among the groups was rejected. In older patients undergoing NSRCT, the appropriate timing of filling is crucial because of their low tolerance [ 5 ]. Filling length is an important index for evaluating the quality of root canal obturation for the prevention of periapical inflammation and the creation of an environment conducive to the healing of apical inflammation. It is essential to ensure hermetic three-dimensional filling and sealing of the apical area and root canal system [ 46 , 47 ]. Radiographic evaluation has been increasingly used to examine the quality of obturation techniques because of its simplicity, reliability, and objectivity [ 48 ]. In our study, the proper filling rate of each group was between 88.33% and 95.00%, whereas the overfilling and underfilling rates were less than 8.33% and 3.33%, respectively, in accordance with those previously reported [ 37 ]. These findings indicate no significant difference in root canal filling quality among the groups, thereby validating the null hypothesis. Another critical factor affecting the three-dimensional sealing of root canal filling was the choice of root canal sealer, particularly hydrophilic bioceramic-based sealers with good fluidity and adhesion, which improves filling and sealing in irregular anatomical structures, such as isthmus, apical bifurcation, and lateral root canal [ 49 ]. The selected bioceramic-based sealers also exhibited excellent biocompatibility, antibacterial activity, low cytotoxicity, stable physicochemical properties, and radiopacity [ 16 , 50 ]. Post-obturation pain is a concern in endodontic therapy, with reported incidences between 3% and 58%[ 51 ]. It can be as high as 80% in the first 24 h [ 52 ]. The factors related to postoperative pain include age, gender, pulpal and periradicular status, degree of infection, tooth type, sinus, preoperative pain, root canal preparation, irrigation and filling methods, and materials [ 53 , 54 ]. Root canal sealers are in direct or close contact with the innervated periapical tissue through apical extrusion or diffusion, which may elicit an immunological response and activate the trigeminal nociceptors, causing postoperative pain [ 55 ]. Previous studies have reported that bioceramic-based sealers combined with different obturation techniques were better than or comparable to resin-based sealers in terms of incidence and intensity of postoperative pain [ 56 – 59 ]; however, no comparison between different types of bioceramic-based sealers have been made. In the present study, C-Root SP combined with the SC technique has certain advantages in relieving postoperative pain (incidence and intensity), particularly on day 1 after operation; thus, the null hypothesis that no significant difference exists in postoperative pain response among the three groups was partially rejected. One of the reasons is that calcium silicate was replaced with strontium silicate in C-Root SP [ 24 , 27 ]. In addition, Strontium Ranelate induces analgesia in patients with arthritis by inhibiting the release of inflammatory cytokines into the inflamed joints [ 60 ]. Therefore, we speculated that C-Root SP may alleviate postoperative pain following root canal filling and is partially related to strontium silicate. Several clinical trials, retrospective studies, systematic reviews, and meta­analyses revealed that clinical outcomes of using calcium silicate–based sealers combined with different obturation techniques were similar to or better than other obturation materials and techniques. In particular, bioceramic-based sealers can play crucial roles in reducing acute inflammation and promoting periapical healing [ 9 , 11 , 61 , 62 ]. However, the clinical effects of using strontium silicate–based sealers combined with different obturation techniques remain unclear. This randomized clinical study aimed to investigate success rates and changes in PAI scores using C-Root SP combined with different obturation techniques in older patients. Both success rates and PAI scores were similar for the patients allocated to all groups at baseline and 1 year of follow-up using either per-protocol or ITT analysis. Our study’s treatment approaches effectively reduced the PAI score from 2.93–3.00 at baseline to 1.89–2.10 after 1 year of follow-up ( P 91.23%; however, no significant differences were observed between the four groups ( F = 0.680, P = 0.892). This finding is consistent with those of previous studies [ 9 , 36 ]; hence, the relevant null hypothesis is accepted. Therefore, the clinical efficacy of C-Root SP combined with different obturation techniques and iRoot SP combined with SC in older patients can be deemed equivalent. Finally, several factors affect the success rate of root canal therapy in older patients, including root canal preparation, disinfection, and obturation. These steps can be effectively performed if the overall treatment is successful, particularly when considering the unique challenges posed by dental pulp aging. With age, pulp tissue undergoes changes such as increased fibrosis and reduced vascularization [ 63 ], making endodontic treatment initiation more challenging. Because this study included older patients, the root canal size was smaller because of pathological and age-related calcification. Even anterior teeth with single root canal rarely required preparation beyond X4 (40/0.06) or X5 (50/0.06). Although removing root canal infections was crucial, appropriate irrigation and disinfection strategies were also essential for infection control. Furthermore, excessive removal of the root canal wall should be avoided, as thinning increases the risk of root fractures [ 64 ]. The operator’s expertise is a key factor, as their skills and knowledge in providing high-quality endodontic treatment affect the prognosis and outcomes of therapy [ 13 ]. To the best of our knowledge, this is the first clinical trial on the use of strontium silicate–based sealers combined with different obturation techniques in older patients. The limitations of this study include the relatively small number of teeth and patients, diversity of periapical tooth status, not using the split­mouth design to eliminate individual factors [ 58 ], and short observation duration. Nevertheless, the patients in this study are still in a recall program to collect long-term data and validate the outcomes of our findings. Conclusions Within the limitations of this clinical randomized study, the following conclusions can be drawn: C-Root SP combined with different obturation techniques presented outcomes similar to those of iRoot SP combined with the SC technique in terms of root canal filling length, success rate, and changes in PAI scores in older patients. The SC technique could significantly improve the efficiency of clinical procedures. It may have an advantage in reducing the incidence and intensity of early postoperative pain when combined with C-Root SP. Nevertheless, multicenter prospective long-term clinical trials involving larger sample sizes and different diagnoses should be conducted to obtain specific conclusions regarding the outcomes of using these obturation techniques and sealers. Abbreviations NSRCT: nonsurgical root canal treatment SC: single-cone technique WVC: warm vertical compaction technique CLC: cold lateral condensation technique WL: Working length GP: gutta-percha NRS: numeric rating scale PAI: periapical index ITT: intention-to-treat Declarations Author contributions F.C.: conceptualization, methodology, investigation, project administration funding acquisition. L.D., J.L., and P.X.: investigation, data curation and drafting and writing the manuscript. S.H. and L.L.: investigation and data curation. C.X. and L.W.: radiographically analysis. H.H. and Q.L.: writing, review & editing, and supervision. All authors contributed to the study conception and design and read and approved the final manuscript. Funding This work was supported by the Youth Independent Innovation Science Fund Project of Chinese PLA General Hospital (grant number: 22QNFC037) and the 2023 Hospital-Level New Service Projects of Chinese PLA General Hospital (grant number: 2023-2-4). Ethics approval and consent to participate Ethical approval for this study was obtained from the Ethics Committee of the First Medical Center of PLA General Hospital (No. S2023-141-01). The study was conducted in accordance with the Declaration of Helsinki. Informed consents were obtained from the patients in written form. Consent for publication Not applicable. Availability of data and materials The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request. Competing interests The authors declare no competing interests. References Hiltunen K, Mäntylä P, Vehkalahti MM. Age- and Time-Related Trends in Oral Health Care for Patients Aged 60 Years and Older in 2007-2017 in Public Oral Health Services in Helsinki, Finland. Int Dent J 2021;71(4):321-327. Kytridou V, Gkikas I, Garcia MN, Cepeda O, Hildebolt CF. A literature review of local and systemic considerations for endodontic treatments in older adults. Gerodontology 2023;40(4):410-421. Razak PA, Richard KM, Thankachan RP, Hafiz KA, Kumar KN, Sameer KM. Geriatric oral health: a review article. J Int Oral Health 2014;6(6):110-116. Azim AA, Griggs JA, Huang GT. The Tennessee study: factors affecting treatment outcome and healing time following nonsurgical root canal treatment. Int Endod J 2016;49(1):6-16. Shakiba B, Hamedy R, Pak JG, Barbizam JV, Ogawa R, White SN. Influence of increased patient age on longitudinal outcomes of root canal treatment: a systematic review. Gerodontology 2017;34(1):101-109. Chung SH, Chang J. Impact of endodontic case difficulty on operating time of single visit nonsurgical endodontic treatment under general anesthesia. BMC Oral Health 2021;21(1):231. de Figueiredo FED, Lima LF, Oliveira LS, Ribeiro MA, Correa MB, Brito-Junior M, Faria ESAL. Effectiveness of a reciprocating single file, single cone endodontic treatment approach: a randomized controlled pragmatic clinical trial. Clin Oral Investig 2020;24(7):2247-2257. Sharki AM, Ali AH. Three-Dimensional Measurement of Obturation Quality of Bioceramic Materials in Filling Artificial Internal Root Resorption Cavities Using Different Obturation Techniques: An In Vitro Comparative Study. J Endod 2024;50(7):997-1003. Kim JH, Cho SY, Choi Y, Kim DH, Shin SJ, Jung IY. Clinical Efficacy of Sealer-based Obturation Using Calcium Silicate Sealers: A Randomized Clinical Trial. J Endod 2022;48(2):144-151. Ng YL, Mann V, Rahbaran S, Lewsey J, Gulabivala K. Outcome of primary root canal treatment: systematic review of the literature -- Part 2. Influence of clinical factors. Int Endod J 2008;41(1):6-31. Sabeti MA, Karimpourtalebi N, Shahravan A, Dianat O. Clinical and Radiographic Failure of Nonsurgical Endodontic Treatment and Retreatment Using Single-cone Technique With Calcium Silicate-based Sealers: A Systematic Review and Meta-analysis. J Endod 2024;50(6):735-746.e731. Atav Ates A, Dumani A, Yoldas O, Unal I. Post-obturation pain following the use of carrier-based system with AH Plus or iRoot SP sealers: a randomized controlled clinical trial. Clin Oral Investig 2019;23(7):3053-3061. Pontoriero DIK, Ferrari Cagidiaco E, Maccagnola V, Manfredini D, Ferrari M. Outcomes of Endodontic-Treated Teeth Obturated with Bioceramic Sealers in Combination with Warm Gutta-Percha Obturation Techniques: A Prospective Clinical Study. J Clin Med 2023;12(8):2867. Seron MA, Nunes GP, Ferrisse TM, Strazzi-Sahyon HB, Dos Santos PH, Gomes-Filho JE, Cintra LTA, Sivieri-Araujo G. Influence of bioceramic sealers on dentinal tubule penetration and antimicrobial effectiveness: a systematic review and meta-analysis of in vitro studies. Odontology 2024;112(3):672-699. Al-Haddad A, Che Ab Aziz ZA. Bioceramic-Based Root Canal Sealers: A Review. Int J Biomater 2016;2016:9753210. Zhang W, Li Z, Peng B. Ex vivo cytotoxicity of a new calcium silicate-based canal filling material. Int Endod J 2010;43(9):769-774. Zhao F, Lei B, Li X, Mo Y, Wang R, Chen D, Chen X. Promoting in vivo early angiogenesis with sub-micrometer strontium-contained bioactive microspheres through modulating macrophage phenotypes. Biomaterials 2018;178:36-47. Pelepenko LE, Marciano MA, Francati TM, Bombarda G, Bessa Marconato Antunes T, Sorrentino F, Martin RA, Boanini E, Cooper PR, Shelton RM, Camilleri J. Can strontium replace calcium in bioactive materials for dental applications? J Biomed Mater Res A 2022;110(12):1892-1911. Lin K, Xia L, Li H, Jiang X, Pan H, Xu Y, Lu WW, Zhang Z, Chang J. Enhanced osteoporotic bone regeneration by strontium-substituted calcium silicate bioactive ceramics. Biomaterials 2013;34(38):10028-10042. Marie PJ. Strontium ranelate: a dual mode of action rebalancing bone turnover in favour of bone formation. Curr Opin Rheumatol 2006;18 Suppl 1:S11-15. Zhang W, Zhao F, Huang D, Fu X, Li X, Chen X. Strontium-Substituted Submicrometer Bioactive Glasses Modulate Macrophage Responses for Improved Bone Regeneration. ACS Appl Mater Interfaces 2016;8(45):30747-30758. Nishad KV, Komath M, Unnikrishnan G. Synthesis of strontium orthosilicate (Sr2SiO4) by sol-gel method for the use in endodontic cements to enhance bioactivity and radio-contrast. Materials Research Express 2019;6(10):105401. Yang XL, Zheng TX, Li W, Wang WL, Yin ZH, Bai YH. In vitro study on cytotoxicity, osteogenic potential and antibacterial activity of silicate root canal sealers. Shanghai Kou Qiang Yi Xue 2023;32(3):246-250. Jing Y, Gong T, Duan C, Wang H, Zhang C, Neelakantan P. In vitro cytocompatibility and osteogenic potential of calcium silicate-based dental cements in a root canal-filling model. J Int Med Res 2020;48(4):300060519894801. Zhou G, Zhao Y, Cai L, Liu L, Li X, Sun L, Deng J. Cytotoxicity and cell migration evaluation of a strontium silicate-based root canal sealer on stem cells from rat apical papilla: an in vitro study. BMC Oral Health 2024;24(1):1023. Yang X, Xia L, Chen Y, Jiang L, Zheng T, Bai Y. Cytotoxicity and Bone Biocompatibility of the C-Root SP Experimental Root Canal Sealer. Aust Endod J 2024. Zanza A, Reda R, Vannettelli E, Donfrancesco O, Relucenti M, Bhandi S, Patil S, Mehta D, Krithikadatta J, Testarelli L. The Influence of Thermomechanical Compaction on the Marginal Adaptation of 4 Different Hydraulic Sealers: A Comparative Ex Vivo Study. J Compos Sci 2023;7(1):10. Moher D, Hopewell S, Schulz KF, Montori V, Gøtzsche PC, Devereaux PJ, Elbourne D, Egger M, Altman DG. CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. Bmj 2010;340:c869. Saini HR, Tewari S, Sangwan P, Duhan J, Gupta A. Effect of different apical preparation sizes on outcome of primary endodontic treatment: a randomized controlled trial. J Endod 2012;38(10):1309-1315. Viechtbauer W, Smits L, Kotz D, Budé L, Spigt M, Serroyen J, Crutzen R. A simple formula for the calculation of sample size in pilot studies. J Clin Epidemiol 2015;68(11):1375-1379. Ferreira NS, Gollo EKF, Boscato N, Arias A, Silva E. Postoperative pain after root canal filling with different endodontic sealers: a randomized clinical trial. Braz Oral Res 2020;34:e069. Mannocci F, Bhuva B, Roig M, Zarow M, Bitter K. European Society of Endodontology position statement: The restoration of root filled teeth. Int Endod J 2021;54(11):1974-1981. Sjogren U, Hagglund B, Sundqvist G, Wing K. Factors affecting the long-term results of endodontic treatment. J Endod 1990;16(10):498-504. Orstavik D, Kerekes K, Eriksen HM. The periapical index: a scoring system for radiographic assessment of apical periodontitis. Endod Dent Traumatol 1986;2(1):20-34. Orstavik D. Time-course and risk analyses of the development and healing of chronic apical periodontitis in man. Int Endod J 1996;29(3):150-155. Chybowski EA, Glickman GN, Patel Y, Fleury A, Solomon E, He J. Clinical Outcome of Non-Surgical Root Canal Treatment Using a Single-cone Technique with Endosequence Bioceramic Sealer: A Retrospective Analysis. J Endod 2018;44(6):941-945. Coşar M, Kandemir Demirci G, Çalışkan MK. The effect of two different root canal sealers on treatment outcome and post-obturation pain in single-visit root canal treatment: A prospective randomized clinical trial. Int Endod J 2023;56(3):318-330. Lakens D. Equivalence Tests: A Practical Primer for t Tests, Correlations, and Meta-Analyses. Soc Psychol Personal Sci 2017;8(4):355-362. Hasheminia SM, Farhad AR, Saatchi M, Nejad HS, Sanei M. Mechanical or cold lateral compaction: The incidence of dentinal defects. Dent Res J (Isfahan) 2015;12(6):513-519. Chellapilla PK, Boddeda MR, Jyothi M, Uppalapati LV, Konagala RK, Dasari L. Influence of obturating techniques on root dentin crack propagation: A micro-computed tomography assessment. J Conserv Dent 2021;24(1):72-76. Pirani C, Zamparini F, Peters OA, Iacono F, Gatto MR, Generali L, Gandolfi MG, Prati C. The fate of root canals obturated with Thermafil: 10-year data for patients treated in a master's program. Clin Oral Investig 2019;23(8):3367-3377. Pirani C, Friedman S, Gatto MR, Iacono F, Tinarelli V, Gandolfi MG, Prati C. Survival and periapical health after root canal treatment with carrier-based root fillings: five-year retrospective assessment. Int Endod J 2018;51 Suppl 3:e178-e188. Camilleri J. Sealers and warm gutta-percha obturation techniques. J Endod 2015;41(1):72-78. Iglecias EF, Freire LG, de Miranda Candeiro GT, Dos Santos M, Antoniazzi JH, Gavini G. Presence of Voids after Continuous Wave of Condensation and Single-cone Obturation in Mandibular Molars: A Micro-computed Tomography Analysis. J Endod 2017;43(4):638-642. Chew ST, Eshak Z, Al-Haddad A. Evaluation of interfacial adaptation and penetration of bioceramic-based sealers in oval root canals: A confocal laser scanning microscope study. Microsc Res Tech 2023;86(7):754-761. Tajonar R, Sánchez-Mendieta KP, Martínez-Martínez RE, Domínguez-Pérez RA. Periapical Healing of Endodontically Treated Teeth Filled Only in the Apical Third: A Randomized Controlled Trial. Eur Endod J 2018;3(1):24-30. Alenezi MA, Al-Nazhan SA, Al-Omari MA. Three-dimensional evaluation of root canal morphology of maxillary first premolars: Micro-computed tomographic study. Saudi Dent J 2022;34(7):611-616. Habib AA, Doumani MD, Nassani MZ, Shamsy E, Jto BS, Arwadİ HA, Mohamed SA. Radiographic Assessment of the Quality of Root Canal Fillings Performed by Senior Dental Students. Eur Endod J 2018;3(2):101-106. Wuersching SN, Diegritz C, Hickel R, Huth KC, Kollmuss M. A comprehensive in vitro comparison of the biological and physicochemical properties of bioactive root canal sealers. Clin Oral Investig 2022;26(10):6209-6222. Ferreira GC, Pinheiro LS, Nunes JS, de Almeida Mendes R, Schuster CD, Soares RG, Kopper PMP, de Figueiredo JAP, Grecca FS. Evaluation of the biological and physicochemical properties of calcium silicate-based and epoxy resin-based root canal sealers. J Biomed Mater Res B Appl Biomater 2022;110(6):1344-1353. Sathorn C, Parashos P, Messer H. The prevalence of postoperative pain and flare-up in single- and multiple-visit endodontic treatment: a systematic review. Int Endod J 2008;41(2):91-99. Pak JG, White SN. Pain prevalence and severity before, during, and after root canal treatment: a systematic review. J Endod 2011;37(4):429-438. Alí A, Olivieri JG, Duran-Sindreu F, Abella F, Roig M, García-Font M. Influence of preoperative pain intensity on postoperative pain after root canal treatment: A prospective clinical study. J Dent 2016;45:39-42. Wang C, Xu P, Ren L, Dong G, Ye L. Comparison of post-obturation pain experience following one-visit and two-visit root canal treatment on teeth with vital pulps: a randomized controlled trial. Int Endod J 2010;43(8):692-697. Ruparel NB, Ruparel SB, Chen PB, Ishikawa B, Diogenes A. Direct effect of endodontic sealers on trigeminal neuronal activity. J Endod 2014;40(5):683-687. Seron MA, Nunes GP, Ferrisse TM, Strazzi-Sahyon HB, Victorino FR, Dos Santos PH, Gomes-Filho JE, Cintra LTA, Sivieri-Araujo G. Postoperative pain after root canal filling with bioceramic sealers: a systematic review and meta-analysis of randomized clinical trials. Odontology 2023;111(4):793-812. Yu YH, Kushnir L, Kohli M, Karabucak B. Comparing the incidence of postoperative pain after root canal filling with warm vertical obturation with resin-based sealer and sealer-based obturation with calcium silicate-based sealer: a prospective clinical trial. Clin Oral Investig 2021;25(8):5033-5042. Alzoubi F, Alajmi S, Alkandari A, Alqahtani S, Alanezi A, Setzer FC. Post-operative pain in non-surgical root canal treatment after sealer-based obturation versus warm vertical compaction: A randomized clinical trial. Int Endod J 2024;57(9):1168-1179. Graunaite I, Skucaite N, Lodiene G, Agentiene I, Machiulskiene V. Effect of Resin-based and Bioceramic Root Canal Sealers on Postoperative Pain: A Split-mouth Randomized Controlled Trial. J Endod 2018;44(5):689-693. de Melo Nunes R, Martins MR, da Silva Junior FS, de Melo Leite AC, Girão VC, de Queiroz Cunha F, Marinho AL, Pinto AC, Rocha FA. Strontium ranelate analgesia in arthritis models is associated to decreased cytokine release and opioid-dependent mechanisms. Inflamm Res 2015;64(10):781-787. Radwanski M, Pietrzycka K, Eyüboğlu TF, Özcan M, Lukomska-Szymanska M. Clinical outcome of non-surgical root canal treatment using different sealers and techniques of obturation in 237 patients: A retrospective study. Clin Oral Investig 2024;28(9):479. Li J, Chen L, Zeng C, Liu Y, Gong Q, Jiang H. Clinical outcome of bioceramic sealer iRoot SP extrusion in root canal treatment: a retrospective analysis. Head Face Med 2022;18(1):28. Rutz da Silva F, Padilha EZ, Cândido VS, Cavassim R, Pereira AC, Hebling E. Relationship between quality of root canal obturation and periapical lesion in elderly patients: a systematic review. Gerodontology 2016;33(3):290-298. Huang D, Wang X, Liang J, Ling J, Bian Z, Yu Q, Hou B, Chen X, Li J, Ye L, Cheng L, Xu X, Hu T, Wu H, Guo B, Su Q, Chen Z, Qiu L, Chen W, Wei X, Huang Z, Yu J, Lin Z, Zhang Q, Yang D, Zhao J, Pan S, Yang J, Wu J, Pan Y, Xie X, Deng S, Huang X, Zhang L, Yue L, Zhou X. Expert consensus on difficulty assessment of endodontic therapy. Int J Oral Sci 2024;16(1):22. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 15 May, 2025 Read the published version in BMC Oral Health → Version 1 posted Editorial decision: Accepted 05 May, 2025 Submission checks completed at journal 03 May, 2025 First submitted to journal 28 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5548977","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":449151115,"identity":"4897d503-3801-4a9e-8176-9a2340da1c42","order_by":0,"name":"Liping Dong","email":"","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Liping","middleName":"","lastName":"Dong","suffix":""},{"id":449151116,"identity":"229bbc8d-2db8-4336-9957-1024860d9621","order_by":1,"name":"Jianshe Li","email":"","orcid":"","institution":"Southern Medical Branch of PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jianshe","middleName":"","lastName":"Li","suffix":""},{"id":449151117,"identity":"2a9facd8-9e52-430e-a65d-5697af46be01","order_by":2,"name":"Peng Xue","email":"","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Peng","middleName":"","lastName":"Xue","suffix":""},{"id":449151118,"identity":"40fa50a3-1429-4066-b7db-f6a001c4e394","order_by":3,"name":"Suixin Hu","email":"","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Suixin","middleName":"","lastName":"Hu","suffix":""},{"id":449151120,"identity":"93b51f7d-c277-4775-8fad-b73f60e2cc7c","order_by":4,"name":"Chen Xu","email":"","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Chen","middleName":"","lastName":"Xu","suffix":""},{"id":449151121,"identity":"921a1593-a26e-4e1c-b7f4-d31a132a8c6d","order_by":5,"name":"Lin Wang","email":"","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Lin","middleName":"","lastName":"Wang","suffix":""},{"id":449151122,"identity":"97e01ef2-9c8b-4a38-a3ef-2cf1dda2c669","order_by":6,"name":"Liu Liu","email":"","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Liu","middleName":"","lastName":"Liu","suffix":""},{"id":449151123,"identity":"2f4e0e08-07b8-4d28-bb4e-68556ccaee21","order_by":7,"name":"Qiang Luo","email":"","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Qiang","middleName":"","lastName":"Luo","suffix":""},{"id":449151124,"identity":"8bf756c4-fa28-413e-bae9-dbdd29c48984","order_by":8,"name":"Huixia He","email":"","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Huixia","middleName":"","lastName":"He","suffix":""},{"id":449151125,"identity":"f0f06541-ba7c-4bf1-9745-71462a302492","order_by":9,"name":"Fei Chen","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAwklEQVRIiWNgGAWjYHCCBGYGAxsefvYGkrQUpMlJ9hwgwRpmhg+HjQ1uJBCpnL//wMPPBQbMiRtuPt54g6HGJpqgFokDB5KlZxiwJc68nVZswXAsLbeBkBYDxoY0Zh4DnsS+2zlmEowNh4nQwswA0iKR2HDzDLFa2MBaDIwFbvAQqUXiDEOyNI9BAjCQgX5JIMYv/P1nEj/z/PkPjMrDG298qLEhrIWBgScB7kiJBNzKkAH7AYQW4nSMglEwCkbBSAMAHDs7k1i3ojoAAAAASUVORK5CYII=","orcid":"","institution":"The First Medical Center, Chinese PLA General Hospital","correspondingAuthor":true,"prefix":"","firstName":"Fei","middleName":"","lastName":"Chen","suffix":""}],"badges":[],"createdAt":"2024-11-29 12:08:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5548977/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5548977/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12903-025-06117-9","type":"published","date":"2025-05-15T15:58:11+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82042505,"identity":"f4fe5b87-ed31-401f-8f89-ffb0893b35db","added_by":"auto","created_at":"2025-05-06 09:21:43","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":2693328,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of patient allocations. C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique.\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-5548977/v1/a77643101a2a2ec4ddd9eba5.png"},{"id":82042510,"identity":"3b6a62e8-3945-4408-a817-532710f8cb8e","added_by":"auto","created_at":"2025-05-06 09:21:43","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":10172785,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative (A, B, and C), postoperative (D, E, and F), and recall (G, H, and I) radiographs of the outcomes of healed, healing, and not healed teeth in group A (C-R combined with SC); C-R; C-Root SP; SC, single-cone technique.\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-5548977/v1/f5e8ce4c34360c5c41f1097a.png"},{"id":82042508,"identity":"d086761c-1408-4dee-84ff-1bbadd3becd8","added_by":"auto","created_at":"2025-05-06 09:21:43","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":10558339,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative (A, B and C), postoperative (D, E and F), and recall (G, H and I) radiographs of the outcomes of healed, healing and not healed teeth respectively in group B (C-R combined with WVC); C-R; C-Root SP; WVC, warm vertical compaction technique.\u003c/p\u003e","description":"","filename":"Fig.3.png","url":"https://assets-eu.researchsquare.com/files/rs-5548977/v1/ea46bc354a47616d07787ebb.png"},{"id":82042506,"identity":"89bb4b35-66f1-408b-8569-cc22621591bd","added_by":"auto","created_at":"2025-05-06 09:21:43","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":8716990,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative (A, B and C), postoperative (D, E and F), and recall (G, H and I) radiographs of the outcomes of healed, healing and not healed teeth respectively in group C (C-R combined with CLC); C-R; C-Root SP; CLC, cold lateral condensation technique.\u003c/p\u003e","description":"","filename":"Fig.4.png","url":"https://assets-eu.researchsquare.com/files/rs-5548977/v1/8bc5e575e02b016dc2622053.png"},{"id":82042507,"identity":"b9ceb86a-f71e-4be2-8908-16ddde0ba145","added_by":"auto","created_at":"2025-05-06 09:21:43","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":10587444,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative (A, B and C), postoperative (D, E and F), and recall (G, H and I) radiographs of the outcomes of healed, healing and not healed teeth respectively in group D (i-R combined with SC); i-R, iRoot SP; SC, single-cone technique.\u003c/p\u003e","description":"","filename":"Fig.5.png","url":"https://assets-eu.researchsquare.com/files/rs-5548977/v1/49967f3365e798459066b5f3.png"},{"id":83067908,"identity":"4e52cc87-3003-4d1d-bab8-ce77089758b3","added_by":"auto","created_at":"2025-05-19 16:07:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":39271826,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5548977/v1/9b6316fd-3d18-4f81-9dbb-a4522b548114.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Clinical outcomes of nonsurgical root canal treatment using C-Root SP combined with different obturation techniques in older patients: a randomized controlled clinical trial","fulltext":[{"header":"Background","content":"\u003cp\u003eAlthough the clinical demand for endodontic therapy is increasing among older individuals, they are more likely to undergo tooth extraction than receive periodontal and endodontic treatment and restoration [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Because of the lack of appropriate prevention and maintenance, along with other factors such as low salivary flow, a soft diet with high carbohydrates, and systemic diseases, older patients often present with extensive periapical infection, combined with periodontal destruction, substantial tooth defect, and root caries that would affect periapical lesion healing after nonsurgical root canal treatment (NSRCT) and subsequent tooth rehabilitation [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Furthermore, increased canal calcification with aging poses challenges in diagnosis as well as in root canal cleaning, shaping, and obturation [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. These factors, in combination with anatomical complexities, may prolong the operation duration and cause postoperative pain and fatigue in the maxillofacial joints and muscles, affecting the patient\u0026rsquo;s acceptance of the treatment [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Moreover, systemic disorders may contribute to the safe and successful completion of NSRCT, whereas increased patient age does not decrease its success or survival rates [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Therefore, aging and its associated systemic disorders do not preclude endodontic treatment in older individuals [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAdequate root canal instrumentation, irrigation, and medication are essential for eliminating endodontic pathogens [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], and three-dimensional obturation is crucial for preventing root canal re-infection by sealing in residual pathogens and blocking infiltration from apical tissues [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Thus, hermetic sealing of the root canal system is one of the preconditions to ensure successful NSRCT [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Root canal sealers are used to enhance sealing ability by filling any voids and irregularities between the root canal wall and gutta-percha [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Multiple root canal sealers have been used in clinical settings in combination with different obturation techniques [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Bioactive properties of bioceramic-based sealers can promote periapical healing and facilitate dentine mineralization. The excellent flowability of this material, high alkaline pH, and less cytotoxicity are beneficial to canal sealing, microbial elimination, hydroxyapatite formation, and subsequent periapical tissue healing [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Among them, a novel bioceramic-based sealer, C-Root SP (C-root Dental Medical Devices Co. Ltd. Beijing, China), has recently been developed using a strontium silicate\u0026ndash;based setting system. Strontium is a trace element in bone that can increase the expression of angiogenic factors in cells, thereby stimulating angiogenesis and promoting bone tissue repair [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Animal experiments have confirmed that strontium can substitute calcium in bioactive materials to stimulate the proliferation, osteogenesis, and angiogenesis of bone marrow stromal cells without exerting adverse local or systemic effects [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Furthermore, strontium ions share intracellular transport pathways with calcium, imparting them with a strong affinity for binding to the bone matrix. Strontium can reduce osteoclast activity and bone resorption \u003cem\u003ein vitro\u003c/em\u003e [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], and it exerts immunomodulatory effects and radiopacity [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Multiple \u003cem\u003ein vitro\u003c/em\u003e studies have reported that C-Root SP exhibits high biocompatibility, biological activity, and low cytotoxicity in terms of cell proliferation. It also exhibits antibacterial activity against \u003cem\u003eEnterococcus faecalis\u003c/em\u003e [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], superior osteogenic potential compared with AH-Plus [\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], and reasonable marginal adaptation [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], making it a promising alternative for root canal obturation. Although C-Root SP has been in the market for \u0026gt;\u0026thinsp;4 years, well-controlled clinical studies on its clinical outcomes in combination with different obturation techniques are limited. This study aimed to evaluate the clinical efficacy and outcomes of C-Root SP in combination with the single-cone (SC) technique, warm vertical compaction (WVC) technique, and cold lateral condensation (CLC) technique in older patients requiring root canal therapy. iRoot SP (Innovative BioCeramix Inc., Vancouver, Canada), a calcium silicate\u0026ndash;based sealer combined with the SC, was used as a control. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e lists the composition and lot numbers of these two premixed bioceramic-based sealers [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. The null hypothesis of this study is that there is no significant difference in operation duration, postoperative pain response, obturation length, and 1-year success rate between C-Root SP combined with different obturation techniques and iRoot SP combined with SC in older patients.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComposition of the premixed bioceramic-based sealers\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSealers\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eManufacturer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLot number\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eComposition\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC-Root SP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC-root Dental Medical Devices Co. Ltd. Beijing, China\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20230403\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStrontium silicate, calcium phosphate, calcium hydroxide, zirconium dioxide, fillers and thickening agents\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eiRoot SP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInnovative BioCeramix Inc., Vancouver, Canada\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23001SP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTricalcium silicates, dicalcium silicates, calcium phosphate monobasic, calcium hydroxide, zirconium oxide, fillers, and thickening agents\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003eParticipant enrollment\u003c/h2\u003e\n \u003cp\u003eThis prospective, single-center, single-blind, parallel, randomized clinical trial was conducted in accordance with the Consolidated Standards of Reporting Trials (CONSORT, 2010) [\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e] and ethical principles of the Declaration of Helsinki. The study was approved by the Ethics Committee of the Chinese PLA General Hospital (No. S2023-141-01) and was retrospectively registered at the Chinese Clinical Trial Registry (ChiCTR2400092580; date of registration: November 19, 2024). Patients who required NSRCT were enrolled after obtaining informed consent. All patients were informed of the benefits and risks and required follow-up assessments. They were consecutively treated between January and May 2023. Follow-up assessments were performed at least 1 year postoperatively. The flow of participants throughout the study is illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. The inclusion and exclusion criteria were as follows:\u003c/p\u003e\n \u003cp\u003eInclusion criteria:\u003c/p\u003e\n \u003cul\u003e\n \u003cli\u003e\n \u003cp\u003ePatients aged\u0026thinsp;\u0026ge;\u0026thinsp;60 years at recruitment.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients classified according to the American Society of Anesthesiologists (ASA) physical status as ASA I and ASA II.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients with no known allergies to any material used in the study.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients diagnosed with pulp necrosis and those with radiographic evidence of apical periodontitis (\u0026lt;\u0026thinsp;5 mm in diameter), including symptomatic apical periodontitis, asymptomatic apical periodontitis, and chronic apical abscess.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePeriodontally healthy patients or those with a pocket depth\u0026thinsp;\u0026le;\u0026thinsp;4 mm.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients with tooth mobility limited to grade 0 or 1.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eFor a participant with multiple teeth eligible for the study, only one tooth was randomly selected.\u003c/p\u003e\n \u003c/li\u003e\n \u003c/ul\u003e\n \u003cp\u003eExclusion criteria:\u003c/p\u003e\n \u003cul\u003e\n \u003cli\u003e\n \u003cp\u003ePatients with severe systemic diseases, allergy to local anesthetic drugs or multiple drugs, and other absolute contraindications for the treatment.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients with malignant tumors and taking oral or injected bisphosphate drugs.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients with extreme fear and psychological disorders that make understanding and cooperation during treatment difficult.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients with grade 2 or 3 affected tooth mobility or periodontal\u0026ndash;endodontic lesions.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients who underwent endodontic treatment (completed or not), with immature roots, with internal or external root resorption, with root fracture, or with perforation in the affected teeth.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003ePatients with excessive tension in the orbicularis oris muscle and a mouth opening of less than three transverse fingers, making it highly difficult to accurately utilize the required tools in the mouth.\u003c/p\u003e\n \u003c/li\u003e\n \u003c/ul\u003e\n\u003c/div\u003e\n\u003ch3\u003eSample size determination\u003c/h3\u003e\n\u003cp\u003eThe minimum estimated sample size was calculated using the G\u003csup\u003e*\u003c/sup\u003ePower 3.1 software (Heinrich Heine, University of D\u0026uuml;sseldorf, D\u0026uuml;sseldorf, Germany) based on previous research data [\u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e]. In the calculation for the similarity trial, an equivalence limit of 0.5, standard deviation of 0.73, type I error of 0.05, and power test of 0.90 were used. The sample size was increased by 20% to compensate for dropouts. Finally, 60 teeth/patients were included in each experimental condition.\u003c/p\u003e\n\u003ch3\u003eRandomization\u003c/h3\u003e\n\u003cp\u003eThe patients were allocated to four groups according to two bioceramic-based sealers, C-Root SP and iRoot SP, combined three different obturation techniques using a randomized block design with blocks of 60 patients/teeth each. The group allocation was concealed using a predetermined computer-generated randomization list. The number of tables was prepared separately for three experimental groups, namely, group A (C-Root SP combined with the SC technique), group B (C-Root SP combined with the WVC technique), and group C (C-Root SP combined with the CLC technique), and a control group, namely, group D (iRoot SP combined with the SC technique). Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e presents the demographic characteristics of the study population and the distribution of treated teeth according to group. Because the present study was an interventional study, clinicians were not blinded to the procedures being performed. Patients were not informed about the treatment (control or experimental) to which they were allocated.\u003c/p\u003e\n\u003ch3\u003eRoot canal preparation techniques\u003c/h3\u003e\n\u003cp\u003eAfter a thorough clinical and radiographic evaluation based on the inclusion/exclusion criteria, teeth that met the inclusion criteria were treated in two visits. All teeth were isolated using a rubber dam during root canal treatment. The procedures were performed using a microscope (OPMI Sensera; Carl Zeiss, Germany). The working length (WL) was determined using an apex locator (Raypex 6, VDW GmbH, Germany) and validated radiographically to be 1 mm less than the radiographic apex.\u003c/p\u003e\n\u003cp\u003eFor each group, apical preparation was performed using ISO stainless steel hand files (size #10\u0026ndash;15, K-reamers, MANI, Japan), beginning with the selection of the first file to bind at the WL. Subsequently, rotary files (ProTaper Next, Dentsply Maillefer, Switzerland) with an endodontic motor (X\u0026shy;Smart Plus, Dentsply Maillefer, Switzerland) were used for mechanical preparation according to the manufacturer\u0026rsquo;s recommendations (speed: 200 rpm; torque: 2 Ncm). In the presence of EDTA gel, the rotary files were inserted into the canal up to the full WL in the following sequence: X1 (size: #17; taper: 0.04), X2 (size: #25; taper: 0.06), and X3 (size: #30; taper: 0.07). The final instrumentation file was set three sizes larger than the first file used to improve periodontitis healing [\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eThe canals of all groups were extensively irrigated using a 2.5% NaOCl root canal irrigant (5 mL for 1 min), and a disposable plastic syringe equipped with a side-vented needle (0.4 \u0026times; 25RW, Sungshim, Korea) was used to reach 1 mm short of the WL. An equal volume of irrigant was administered to each tooth (5 mL applied before instrumentation, 5 mL between files, and a final 5 mL flush following root canal instrumentation). Subsequently, the canals were dried using sterile paper points (Dayading Medical Appliance Co., China). The access cavity was filled with a sterile cotton pellet and temporary filling material (Coltosol F, Coltene/Whaledent, Switzerland), and a calcium hydroxide\u0026ndash;based dressing (ApexCal, Ivoclar Vivadent, Germany) was placed in the root canals [\u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e].\u003c/p\u003e\n\u003ch3\u003eObturation techniques\u003c/h3\u003e\n\u003cp\u003eAfter 7\u0026ndash;10 days, the gutta-percha (GP) master cone was selected and trimmed using a blade to ensure a snug fit in the apical root canal, and it was confirmed using a periapical radiograph (eXpert DC, Gendex Dental Systems, USA) before obturation. Similarly, all obturation procedures were performed under rubber dam isolation.\u003c/p\u003e\n\u003cp\u003eThe teeth in groups A and D were filled with bioceramic-based sealers C-Root SP and iRoot SP, respectively, by injecting the sealer into the coronal third of each canal. A size 25 Lentulo spiral (Paste Carriers, MANI, Japan) coated with additional sealer was introduced 3 mm short of the WL at 300 rpm. Subsequently, a 0.06 taper GP (Dayading Medical Appliance Co., China) was dipped in the corresponding bioceramic-based sealer and introduced into the canal to the WL. A heated plugger (Alpha unit, B\u0026amp;L Biotech USA Inc., USA) was used to sear the GP point at each orifice.\u003c/p\u003e\n\u003cp\u003eThe teeth in group B were filled with 0.06 taper GP (Dayading Medical Appliance Co., China), and C-Root SP was introduced using the master cone. A heated plugger size of 30/.04, 35/.04, or 40/.04 (Alpha unit, B\u0026amp;L Biotech USA Inc, USA) was inserted 3\u0026ndash;5 mm short of the WL, and the remaining canal space was backfilled with additional sealer and thermoplasticized GP using the beta unit (B\u0026amp;L Biotech USA, Inc., USA).\u003c/p\u003e\n\u003cp\u003eFor group C, the root canals were obturated using a 0.06 taper GP cone (Dayading Medical Appliance Co., China), which was selected based on the master apical file. The cone was lightly coated with C-Root SP and placed into the canal up to the WL. Lateral compaction was performed using finger spreaders (MANI, Japan) with a size of 25. The excess filling material was removed using a heated instrument.\u003c/p\u003e\n\u003cp\u003eFor each group, the time from the introduction of the root canal sealer to the completion of a single obturation was recorded, and the coronal access cavities were filled with glass ionomer cement (Fuji IX, GC America, USA) for temporary restoration. The final direct resin restoration or indirect ceramic restoration was performed on the next visit after 7\u0026ndash;10 days, according to the European Society of Endodontology position statement [\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e].\u003c/p\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003ePostoperative radiographic evaluations\u003c/h2\u003e\n \u003cp\u003eThe obturation length was classified into \u0026ldquo;deficient\u0026rdquo; (\u0026gt;\u0026thinsp;2 mm from the radiographic apex), \u0026ldquo;proper\u0026rdquo; (0\u0026ndash;2 mm from the radiographic apex), or \u0026ldquo;overextension\u0026rdquo; (beyond the radiographic apex) [\u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e]. Radiographic evaluations were conducted by two independent, blinded, and experienced endodontists who were trained and calibrated using 150 radiographs unrelated to this study. In cases of disagreement in the assessment of the results, discussions were held until a consensus was reached.\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003eEvaluation of postoperative pain\u003c/h3\u003e\n\u003cp\u003eThe numeric rating scale (NRS) was used for postoperative pain assessment [\u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e]. This scale encompasses the following grades according to pain severity: 0, no pain; 1\u0026ndash;3, mild pain; 4\u0026ndash;6, moderate pain; and 7\u0026ndash;10, severe pain. On days 1, 2, and 7 after treatment, patients were asked to rate their pain level from 0 to 10. In addition, they were reminded to note the number of analgesics they used when necessary. They were contacted via telephone on day 7 to ask about postoperative pain and analgesic intake.\u003c/p\u003e\n\u003ch3\u003eFollow-up evaluation of the treatment outcome\u003c/h3\u003e\n\u003cp\u003eEndodontic treatments were considered failure if pain and/or swelling and/or sinus tract were present. Radiographically, if a pre-existing lesion increased in size or remained the same, the treatment was considered a failure [\u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e]. Periapical radiographs were obtained preoperatively, postoperatively, and at 1-year follow-up. Lesions were reclassified according to the periapical index (PAI) using the following scores [\u003cspan class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e35\u003c/span\u003e]: 1, normal periapical structures; 2, small changes in bone structure; 3, changes in bone structure with some mineral loss; 4, lesions with well-defined radiolucent areas; and 5, severe lesions with exacerbating features. Two blinded, independent, and calibrated examiners (C.X. and L.W.) assessed the radiographs, and each endodontically treated tooth was assigned the highest score recorded for any of its roots.\u003c/p\u003e\n\u003cp\u003eThe treated roots were categorized as follows [\u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e36\u003c/span\u003e]:\u003c/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003e1. Healed: Teeth that are functional, symptom-free, and exhibit no radiographic periapical lesions, with a PAI score of 1 or 2.\u003c/p\u003e\u003cspan\u003e\n \u003cp\u003e2. Healing: Symptom-free teeth that function well, show a reduction in the size of radiographic periapical lesions, and have a PAI score that has decreased from baseline but remains above 2.\u003c/p\u003e\n\u003c/span\u003e\u003cspan\u003e\n \u003cp\u003e3. Not healed: Nonfunctional teeth that have symptoms with or without radiographic periapical lesions or asymptomatic teeth with unchanged, newly developed, or enlarged radiographic periapical lesions. These teeth exhibited PAI score comparable to or worse than the baseline.\u003c/p\u003e\n\u003c/span\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003cp\u003eIn this clinical evaluation, \u0026ldquo;success\u0026rdquo; was defined as belonging to the healed and healing categories, whereas \u0026ldquo;failure\u0026rdquo; referred to teeth that were not healed. In cases of disagreement regarding radiographic and/or clinical evaluations, discussions were held until consensus was reached. Examples of each outcome category among the four groups are presented in Figs. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e.\u003c/p\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eStatistical analysis\u003c/h2\u003e\n \u003cp\u003eAll statistical analyses were performed using IBM SPSS Statistics for Windows (version 26.0, IBM Corp. Released 2019). Continuous variables were expressed as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviations (M\u0026thinsp;\u0026plusmn;\u0026thinsp;SD), and categorical variables were expressed as frequencies with percentages. Normality diagnostic plots and tests were used to test data normality. For the comparisons of the means among the four groups, a two-way analysis of variance was employed for normally distributed data and the Kruskal\u0026ndash;Wallis test for non-normally distributed data. Pearson\u0026rsquo;s chi\u0026shy;squared test or Fisher\u0026rsquo;s exact test was used for categorical variables to evaluate the group differences. Intra\u0026shy; and interobserver agreements were examined using weighted kappa analysis.\u003c/p\u003e\n \u003cp\u003eTo assess differences in postoperative pain among the four groups according to the NRS scores, the nonparametric Mann\u0026ndash;Whitney \u003cem\u003eU\u003c/em\u003e test was used to test the hypothesis that the pain difference among the four groups is not significant. The difference in postoperative pain scores within each treatment group at different time points was assessed using the nonparametric Friedman test. Given the substantial differences identified in the Friedman analysis, Dunn\u0026rsquo;s test with Bonferroni correction was used for pairwise comparisons of time points within the groups [\u003cspan class=\"CitationRef\"\u003e37\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eData from the PAI score change were analyzed using the Mann\u0026ndash;Whitney \u003cem\u003eU\u003c/em\u003e test for equivalence via two one-sided tests [\u003cspan class=\"CitationRef\"\u003e38\u003c/span\u003e], as the hypothesis tested was that the two techniques were equivalent. To assess changes in periapical status, the data were subjected to both per-protocol and intention-to-treat (ITT) analyses. In the case of ITT, the PAI at baseline was repeated for the final evaluation of patients who did not attend their follow-up appointments [\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e]. A \u003cem\u003eP\u003c/em\u003e\u0026shy;value of 0.05 was considered statistically significant in all analyses.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eDemographics, tooth position distribution, and root canal quantitative information\u003c/h2\u003e \u003cp\u003eAccording to the demographic characteristics of the participants, no significant differences were observed in age (\u003cem\u003eF\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.094, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.963) and gender (\u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.133, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.988) among the groups. The positional distribution of the included teeth was similar (\u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.227, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.000). Furthermore, no significant difference was observed in the number of root canals in each group (\u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.294, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.000) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Therefore, the potential impact of these factors can be ignored.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003edemographic features of the population and the distribution of treated teeth in each group\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample size\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e240\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean age (year)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e68.97\u0026thinsp;\u0026plusmn;\u0026thinsp;7.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68.27\u0026thinsp;\u0026plusmn;\u0026thinsp;7.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e68.53\u0026thinsp;\u0026plusmn;\u0026thinsp;8.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e68.47\u0026thinsp;\u0026plusmn;\u0026thinsp;6.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e68.56\u0026thinsp;\u0026plusmn;\u0026thinsp;7.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.963\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender [n] (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.988\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29 (48.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30 (50.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31 (51.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30 (50.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e120 (50.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31 (51.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30 (50.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29 (48.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30 (50.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e120 (50.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLocation (number of root canals)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnterior\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20 (20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19 (19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19 (19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20 (20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e78 (78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePremolar\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19 (27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21 (24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20 (27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e19 (24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e79 (102)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMolar\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21 (64)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20 (56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21 (63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21 (63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e83 (246)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eNote: group A (C-R combined with SC), group B (C-R combined with WVC), group C (C-R combined with CLC) and group D (i-R combined with SC); C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;significance value using chi-square test\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eComparison of duration and length of obturation\u003c/h2\u003e \u003cp\u003eComparison of the obturation duration of each group showed that the filling efficiencies of groups A and D were significantly higher than those of groups B and C (\u003cem\u003eF\u003c/em\u003e\u0026thinsp;=\u0026thinsp;71.823, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001); however, no significant difference was observed between the latter two groups. Furthermore, the use of different root canal sealers in the same obturation technique did not affect the filling duration. All obturated teeth were included in the analysis because of the absence of severely undere-xtended or over-extended obturations (\u0026gt;\u0026thinsp;2 mm). A comparison of the filling length in each group showed that the proper filling rates were higher in group A than in the other three groups. The overfilling rates of the groups were as follows: group A (3.33%)\u0026thinsp;\u0026lt;\u0026thinsp;group D (5.00%)\u0026thinsp;\u0026lt;\u0026thinsp;group C (6.67%)\u0026thinsp;\u0026lt;\u0026thinsp;group B (8.33%). The underfilling rates in groups B, C, and D were higher than those in group A, but the difference was not significant (\u003cem\u003eF\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.318, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.907) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eStatistics of operation time and quality of root canal filling in each group\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eA(n\u0026thinsp;=\u0026thinsp;60)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eB (n\u0026thinsp;=\u0026thinsp;60)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC(n\u0026thinsp;=\u0026thinsp;60)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eD (n\u0026thinsp;=\u0026thinsp;60)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTotal (n\u0026thinsp;=\u0026thinsp;240)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFilling time(second)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61.08\u0026thinsp;\u0026plusmn;\u0026thinsp;12.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81.07\u0026thinsp;\u0026plusmn;\u0026thinsp;10.82\u003csup\u003e①\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e87.12\u0026thinsp;\u0026plusmn;\u0026thinsp;13.70\u003csup\u003e①\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e61.98\u0026thinsp;\u0026plusmn;\u0026thinsp;11.39\u003csup\u003e②③\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e72.81\u0026thinsp;\u0026plusmn;\u0026thinsp;16.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuality of root canal filling\u003c/p\u003e \u003cp\u003e[n] (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.907\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProper\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57 (95.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e53 (88.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e54 (90.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e55 (91.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e219 (91.25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOverextension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (8.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (6.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 (5.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14 (5.83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDeficient\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (1.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7 (2.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eNote: group A (C-R combined with SC), group B (C-R combined with WVC), group C (C-R combined with CLC) and group D (i-R combined with SC); C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;significance value using chi-square test; ①Compared with group A, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.05; ②Compared with group B, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.05; ③Compared with group C, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.05\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eComparison of postoperative pain after obturation\u003c/h2\u003e \u003cp\u003eThe NRS scores of each group on days 1, 2, and 7 after the operation are presented in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. The postoperative rate and degree of pain in each group decreased with time. No severe pain on days 1, 2, and 7 as well as moderate pain on days 2 and 7 were reported in any group. In addition, group A experienced no mild pain on day 7. The postoperative rate of pain (mild and moderate pain) in the groups on day 1 after obturation is as follows: group A (11.67%)\u0026thinsp;\u0026lt;\u0026thinsp;group D (28.33%)\u0026thinsp;\u0026lt;\u0026thinsp;group B (31.67%)\u0026thinsp;\u0026lt;\u0026thinsp;group C (33.33%). The postoperative pain rate in group A significantly differed from those in groups B, C, and D (\u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;9.19, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.027). No significant difference was observed between the four groups in terms of postoperative pain on days 2 (\u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;6.565, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.084) and 7 (\u003cem\u003eF\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.027, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.904).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSeverity and percentage of postoperative pain in each group at various time\u0026shy;points (n;%)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eA(n\u0026thinsp;=\u0026thinsp;60)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eB (n\u0026thinsp;=\u0026thinsp;60)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC(n\u0026thinsp;=\u0026thinsp;60)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eD (n\u0026thinsp;=\u0026thinsp;60)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDays 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMild pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (11.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18 (30.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e18 (30.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e15 (25.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eModerate pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1 (1.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (11.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19 (31.67)\u003csup\u003e①\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20 (33.33)\u003csup\u003e①\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e17 (28.33)\u003csup\u003e①\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.027\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDays 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMild pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10 (16.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8 (13.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e8 (13.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10 (16.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8 (13.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e8 (13.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.084\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDays 7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMild pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1 (1.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1 (1.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1 (1.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1 (1.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.904\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eNote: group A (C-R combined with SC), group B (C-R combined with WVC), group C (C-R combined with CLC) and group D (i-R combined with SC); C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;significance value using chi-square test; ①Compared with group A, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.05; Severe pain on days 1, 2, 7 and moderate pain on days 2, 7 was not included in the table because no case was observed.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eComparison of obturation efficacy after 1 year\u003c/h2\u003e \u003cp\u003eLoss of follow-up and the results of changes in PAI scores 1 year later are presented in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. The follow-up loss rates were 5.00% for Group A, 6.67% for Group B, 5.00% for Group C, and 3.33% for Group D. No significant differences were observed between the groups (\u003cem\u003eF\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.818, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.976). Similar average PAI scores were observed across all groups, regardless of whether the per-protocol or ITT analysis was used (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.988 and \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.986, respectively). All treatment approaches effectively reduced the PAI scores 1 year after treatment (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 for all analyses). In general, the PAI score at baseline ranging from 2.93 to 3.00 was reduced to 1.89 to 2.10 after 1 year of follow-up. Finally, the success rates for all groups after 1 year were in the following order: group D (94.83%)\u0026thinsp;\u0026gt;\u0026thinsp;group A (92.98%)\u0026thinsp;\u0026gt;\u0026thinsp;B group (92.85%)\u0026thinsp;\u0026gt;\u0026thinsp;C group (91.23%); however, no significant differences were observed between the groups (\u003cem\u003eF\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.680, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.892).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ethe efficacy of root canal filling in each group after 1 year\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eRow \u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLost follow-up for 1 year [n] (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3 (5.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4 (6.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3 (5.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2 (3.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e12 (5.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.976\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePer-protocol analyses\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBaseline PAI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.96\u0026thinsp;\u0026plusmn;\u0026thinsp;1.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.93\u0026thinsp;\u0026plusmn;\u0026thinsp;0.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2.97\u0026thinsp;\u0026plusmn;\u0026thinsp;0.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.96\u0026thinsp;\u0026plusmn;\u0026thinsp;1.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.988\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1-year PAI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.04\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.726\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColumn \u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntention to treat analyses\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBaseline PAI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.93\u0026thinsp;\u0026plusmn;\u0026thinsp;1.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.95\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.96\u0026thinsp;\u0026plusmn;\u0026thinsp;1.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.986\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1-year PAI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.92\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;1.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.698\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColumn \u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSuccess [n] (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e53 (92.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e52 (92.85)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e52 (91.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e55 (94.83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e212 (92.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.892\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eNote: group A (C-R combined with SC), group B (C-R combined with WVC), group C (C-R combined with CLC) and group D (i-R combined with SC); C-R; C-Root SP; i-R, iRoot SP; SC, single-cone technique; WVC, warm vertical compaction technique; CLC, cold lateral condensation technique; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;significance value using chi-square test\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eVarious techniques for root canal obturation have been proposed, including SC, lateral condensation, and vertical compaction, and each has its advantages and disadvantages. CLC is widely used because of its low cost and simplicity; however, it lacks adaptability in irregular areas within root canal systems [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e], and excessive lateral pressure may lead to root wall damage and fracture [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. WVC has been recognized as the \u0026ldquo;gold standard\u0026rdquo; for canal obturation [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. Its good three-dimensional adaptability and filling uniformity allow the GP to flow to the irregular areas of the root canal space upon heating and pressing. However, this technique has relatively high technical sensitivity and may cause micro-leakage when microgaps occur in the root canal and the irregular apical foramen, thereby leading to the retention of chemicals and microorganisms [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]. The SC technique, a simple and time-saving procedure, has been frequently used by general practitioners owing to the development of bioceramic-based sealers, which possess better fluidity and do not shrink during the setting phase to reduce pore formation [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. Evidently, the operating efficiency of SC was significantly higher than those of WVC and CLC, regardless of the selected bioceramic-based sealers. Therefore, the null hypothesis of no significant difference in the filling duration among the groups was rejected. In older patients undergoing NSRCT, the appropriate timing of filling is crucial because of their low tolerance [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFilling length is an important index for evaluating the quality of root canal obturation for the prevention of periapical inflammation and the creation of an environment conducive to the healing of apical inflammation. It is essential to ensure hermetic three-dimensional filling and sealing of the apical area and root canal system [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e, \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e]. Radiographic evaluation has been increasingly used to examine the quality of obturation techniques because of its simplicity, reliability, and objectivity [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]. In our study, the proper filling rate of each group was between 88.33% and 95.00%, whereas the overfilling and underfilling rates were less than 8.33% and 3.33%, respectively, in accordance with those previously reported [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. These findings indicate no significant difference in root canal filling quality among the groups, thereby validating the null hypothesis. Another critical factor affecting the three-dimensional sealing of root canal filling was the choice of root canal sealer, particularly hydrophilic bioceramic-based sealers with good fluidity and adhesion, which improves filling and sealing in irregular anatomical structures, such as isthmus, apical bifurcation, and lateral root canal [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. The selected bioceramic-based sealers also exhibited excellent biocompatibility, antibacterial activity, low cytotoxicity, stable physicochemical properties, and radiopacity [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePost-obturation pain is a concern in endodontic therapy, with reported incidences between 3% and 58%[\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. It can be as high as 80% in the first 24 h [\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. The factors related to postoperative pain include age, gender, pulpal and periradicular status, degree of infection, tooth type, sinus, preoperative pain, root canal preparation, irrigation and filling methods, and materials [\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e, \u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e]. Root canal sealers are in direct or close contact with the innervated periapical tissue through apical extrusion or diffusion, which may elicit an immunological response and activate the trigeminal nociceptors, causing postoperative pain [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]. Previous studies have reported that bioceramic-based sealers combined with different obturation techniques were better than or comparable to resin-based sealers in terms of incidence and intensity of postoperative pain [\u003cspan additionalcitationids=\"CR57 CR58\" citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e]; however, no comparison between different types of bioceramic-based sealers have been made. In the present study, C-Root SP combined with the SC technique has certain advantages in relieving postoperative pain (incidence and intensity), particularly on day 1 after operation; thus, the null hypothesis that no significant difference exists in postoperative pain response among the three groups was partially rejected. One of the reasons is that calcium silicate was replaced with strontium silicate in C-Root SP [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. In addition, Strontium Ranelate induces analgesia in patients with arthritis by inhibiting the release of inflammatory cytokines into the inflamed joints [\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e]. Therefore, we speculated that C-Root SP may alleviate postoperative pain following root canal filling and is partially related to strontium silicate.\u003c/p\u003e \u003cp\u003e Several clinical trials, retrospective studies, systematic reviews, and meta\u0026shy;analyses revealed that clinical outcomes of using calcium silicate\u0026ndash;based sealers combined with different obturation techniques were similar to or better than other obturation materials and techniques. In particular, bioceramic-based sealers can play crucial roles in reducing acute inflammation and promoting periapical healing [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e, \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e]. However, the clinical effects of using strontium silicate\u0026ndash;based sealers combined with different obturation techniques remain unclear.\u003c/p\u003e \u003cp\u003eThis randomized clinical study aimed to investigate success rates and changes in PAI scores using C-Root SP combined with different obturation techniques in older patients. Both success rates and PAI scores were similar for the patients allocated to all groups at baseline and 1 year of follow-up using either per-protocol or ITT analysis. Our study\u0026rsquo;s treatment approaches effectively reduced the PAI score from 2.93\u0026ndash;3.00 at baseline to 1.89\u0026ndash;2.10 after 1 year of follow-up (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 for all analyses). Furthermore, the success rate for all four groups in the 1-year review was \u0026gt;\u0026thinsp;91.23%; however, no significant differences were observed between the four groups (\u003cem\u003eF\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.680, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.892). This finding is consistent with those of previous studies [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]; hence, the relevant null hypothesis is accepted. Therefore, the clinical efficacy of C-Root SP combined with different obturation techniques and iRoot SP combined with SC in older patients can be deemed equivalent.\u003c/p\u003e \u003cp\u003eFinally, several factors affect the success rate of root canal therapy in older patients, including root canal preparation, disinfection, and obturation. These steps can be effectively performed if the overall treatment is successful, particularly when considering the unique challenges posed by dental pulp aging. With age, pulp tissue undergoes changes such as increased fibrosis and reduced vascularization [\u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e63\u003c/span\u003e], making endodontic treatment initiation more challenging. Because this study included older patients, the root canal size was smaller because of pathological and age-related calcification. Even anterior teeth with single root canal rarely required preparation beyond X4 (40/0.06) or X5 (50/0.06). Although removing root canal infections was crucial, appropriate irrigation and disinfection strategies were also essential for infection control. Furthermore, excessive removal of the root canal wall should be avoided, as thinning increases the risk of root fractures [\u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e64\u003c/span\u003e]. The operator\u0026rsquo;s expertise is a key factor, as their skills and knowledge in providing high-quality endodontic treatment affect the prognosis and outcomes of therapy [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo the best of our knowledge, this is the first clinical trial on the use of strontium silicate\u0026ndash;based sealers combined with different obturation techniques in older patients. The limitations of this study include the relatively small number of teeth and patients, diversity of periapical tooth status, not using the split\u0026shy;mouth design to eliminate individual factors [\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e], and short observation duration. Nevertheless, the patients in this study are still in a recall program to collect long-term data and validate the outcomes of our findings.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eWithin the limitations of this clinical randomized study, the following conclusions can be drawn: C-Root SP combined with different obturation techniques presented outcomes similar to those of iRoot SP combined with the SC technique in terms of root canal filling length, success rate, and changes in PAI scores in older patients. The SC technique could significantly improve the efficiency of clinical procedures. It may have an advantage in reducing the incidence and intensity of early postoperative pain when combined with C-Root SP. Nevertheless, multicenter prospective long-term clinical trials involving larger sample sizes and different diagnoses should be conducted to obtain specific conclusions regarding the outcomes of using these obturation techniques and sealers.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eNSRCT: nonsurgical root canal treatment\u003c/p\u003e\n\u003cp\u003eSC: single-cone technique\u003c/p\u003e\n\u003cp\u003eWVC: warm vertical compaction technique\u003c/p\u003e\n\u003cp\u003eCLC: cold lateral condensation technique\u003c/p\u003e\n\u003cp\u003eWL: Working length\u003c/p\u003e\n\u003cp\u003eGP: gutta-percha\u003c/p\u003e\n\u003cp\u003eNRS: numeric rating scale\u003c/p\u003e\n\u003cp\u003ePAI: periapical index\u003c/p\u003e\n\u003cp\u003eITT: intention-to-treat\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eF.C.: conceptualization, methodology, investigation, project administration funding acquisition. L.D., J.L.,\u0026nbsp;and P.X.: investigation, data curation and drafting and writing the manuscript. S.H. and L.L.: investigation and data curation. C.X. and L.W.: radiographically analysis. H.H. and Q.L.: writing,\u0026nbsp;review \u0026amp; editing, and supervision. All authors contributed to the study conception and design and read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Youth Independent Innovation Science Fund Project of Chinese PLA General Hospital (grant number: 22QNFC037) and the 2023 Hospital-Level New Service Projects of Chinese PLA General Hospital (grant number: 2023-2-4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval for this study was obtained from the Ethics Committee of the First Medical Center of PLA General Hospital (No. S2023-141-01). The study was conducted in accordance with the Declaration of Helsinki. Informed consents were obtained from the patients in written form.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eHiltunen K, M\u0026auml;ntyl\u0026auml; P, Vehkalahti MM. Age- and Time-Related Trends in Oral Health Care for Patients Aged 60 Years and Older in 2007-2017 in Public Oral Health Services in Helsinki, Finland. Int Dent J 2021;71(4):321-327.\u003c/li\u003e\n \u003cli\u003eKytridou V, Gkikas I, Garcia MN, Cepeda O, Hildebolt CF. A literature review of local and systemic considerations for endodontic treatments in older adults. Gerodontology 2023;40(4):410-421.\u003c/li\u003e\n \u003cli\u003eRazak PA, Richard KM, Thankachan RP, Hafiz KA, Kumar KN, Sameer KM. Geriatric oral health: a review article. J Int Oral Health 2014;6(6):110-116.\u003c/li\u003e\n \u003cli\u003eAzim AA, Griggs JA, Huang GT. The Tennessee study: factors affecting treatment outcome and healing time following nonsurgical root canal treatment. Int Endod J 2016;49(1):6-16.\u003c/li\u003e\n \u003cli\u003eShakiba B, Hamedy R, Pak JG, Barbizam JV, Ogawa R, White SN. Influence of increased patient age on longitudinal outcomes of root canal treatment: a systematic review. Gerodontology 2017;34(1):101-109.\u003c/li\u003e\n \u003cli\u003eChung SH, Chang J. Impact of endodontic case difficulty on operating time of single visit nonsurgical endodontic treatment under general anesthesia. BMC Oral Health 2021;21(1):231.\u003c/li\u003e\n \u003cli\u003ede Figueiredo FED, Lima LF, Oliveira LS, Ribeiro MA, Correa MB, Brito-Junior M, Faria ESAL. Effectiveness of a reciprocating single file, single cone endodontic treatment approach: a randomized controlled pragmatic clinical trial. Clin Oral Investig 2020;24(7):2247-2257.\u003c/li\u003e\n \u003cli\u003eSharki AM, Ali AH. Three-Dimensional Measurement of Obturation Quality of Bioceramic Materials in Filling Artificial Internal Root Resorption Cavities Using Different Obturation Techniques: An In Vitro Comparative Study. J Endod 2024;50(7):997-1003.\u003c/li\u003e\n \u003cli\u003eKim JH, Cho SY, Choi Y, Kim DH, Shin SJ, Jung IY. Clinical Efficacy of Sealer-based Obturation Using Calcium Silicate Sealers: A Randomized Clinical Trial. J Endod 2022;48(2):144-151.\u003c/li\u003e\n \u003cli\u003eNg YL, Mann V, Rahbaran S, Lewsey J, Gulabivala K. Outcome of primary root canal treatment: systematic review of the literature -- Part 2. Influence of clinical factors. Int Endod J 2008;41(1):6-31.\u003c/li\u003e\n \u003cli\u003eSabeti MA, Karimpourtalebi N, Shahravan A, Dianat O. Clinical and Radiographic Failure of Nonsurgical Endodontic Treatment and Retreatment Using Single-cone Technique With Calcium Silicate-based Sealers: A Systematic Review and Meta-analysis. J Endod 2024;50(6):735-746.e731.\u003c/li\u003e\n \u003cli\u003eAtav Ates A, Dumani A, Yoldas O, Unal I. Post-obturation pain following the use of carrier-based system with AH Plus or iRoot SP sealers: a randomized controlled clinical trial. Clin Oral Investig 2019;23(7):3053-3061.\u003c/li\u003e\n \u003cli\u003ePontoriero DIK, Ferrari Cagidiaco E, Maccagnola V, Manfredini D, Ferrari M. Outcomes of Endodontic-Treated Teeth Obturated with Bioceramic Sealers in Combination with Warm Gutta-Percha Obturation Techniques: A Prospective Clinical Study. J Clin Med 2023;12(8):2867.\u003c/li\u003e\n \u003cli\u003eSeron MA, Nunes GP, Ferrisse TM, Strazzi-Sahyon HB, Dos Santos PH, Gomes-Filho JE, Cintra LTA, Sivieri-Araujo G. Influence of bioceramic sealers on dentinal tubule penetration and antimicrobial effectiveness: a systematic review and meta-analysis of in vitro studies. Odontology 2024;112(3):672-699.\u003c/li\u003e\n \u003cli\u003eAl-Haddad A, Che Ab Aziz ZA. Bioceramic-Based Root Canal Sealers: A Review. Int J Biomater 2016;2016:9753210.\u003c/li\u003e\n \u003cli\u003eZhang W, Li Z, Peng B. Ex vivo cytotoxicity of a new calcium silicate-based canal filling material. Int Endod J 2010;43(9):769-774.\u003c/li\u003e\n \u003cli\u003eZhao F, Lei B, Li X, Mo Y, Wang R, Chen D, Chen X. Promoting in vivo early angiogenesis with sub-micrometer strontium-contained bioactive microspheres through modulating macrophage phenotypes. Biomaterials 2018;178:36-47.\u003c/li\u003e\n \u003cli\u003ePelepenko LE, Marciano MA, Francati TM, Bombarda G, Bessa Marconato Antunes T, Sorrentino F, Martin RA, Boanini E, Cooper PR, Shelton RM, Camilleri J. Can strontium replace calcium in bioactive materials for dental applications? J Biomed Mater Res A 2022;110(12):1892-1911.\u003c/li\u003e\n \u003cli\u003eLin K, Xia L, Li H, Jiang X, Pan H, Xu Y, Lu WW, Zhang Z, Chang J. Enhanced osteoporotic bone regeneration by strontium-substituted calcium silicate bioactive ceramics. Biomaterials 2013;34(38):10028-10042.\u003c/li\u003e\n \u003cli\u003eMarie PJ. Strontium ranelate: a dual mode of action rebalancing bone turnover in favour of bone formation. Curr Opin Rheumatol 2006;18 Suppl 1:S11-15.\u003c/li\u003e\n \u003cli\u003eZhang W, Zhao F, Huang D, Fu X, Li X, Chen X. Strontium-Substituted Submicrometer Bioactive Glasses Modulate Macrophage Responses for Improved Bone Regeneration. ACS Appl Mater Interfaces 2016;8(45):30747-30758.\u003c/li\u003e\n \u003cli\u003eNishad KV, Komath M, Unnikrishnan G. Synthesis of strontium orthosilicate (Sr2SiO4) by sol-gel method for the use in endodontic cements to enhance bioactivity and radio-contrast. Materials Research Express 2019;6(10):105401.\u003c/li\u003e\n \u003cli\u003eYang XL, Zheng TX, Li W, Wang WL, Yin ZH, Bai YH. In vitro study on cytotoxicity, osteogenic potential and antibacterial activity of silicate root canal sealers. Shanghai Kou Qiang Yi Xue 2023;32(3):246-250.\u003c/li\u003e\n \u003cli\u003eJing Y, Gong T, Duan C, Wang H, Zhang C, Neelakantan P. In vitro cytocompatibility and osteogenic potential of calcium silicate-based dental cements in a root canal-filling model. J Int Med Res 2020;48(4):300060519894801.\u003c/li\u003e\n \u003cli\u003eZhou G, Zhao Y, Cai L, Liu L, Li X, Sun L, Deng J. Cytotoxicity and cell migration evaluation of a strontium silicate-based root canal sealer on stem cells from rat apical papilla: an in vitro study. BMC Oral Health 2024;24(1):1023.\u003c/li\u003e\n \u003cli\u003eYang X, Xia L, Chen Y, Jiang L, Zheng T, Bai Y. Cytotoxicity and Bone Biocompatibility of the C-Root SP Experimental Root Canal Sealer. Aust Endod J 2024.\u003c/li\u003e\n \u003cli\u003eZanza A, Reda R, Vannettelli E, Donfrancesco O, Relucenti M, Bhandi S, Patil S, Mehta D, Krithikadatta J, Testarelli L. The Influence of Thermomechanical Compaction on the Marginal Adaptation of 4 Different Hydraulic Sealers: A Comparative Ex Vivo Study. J Compos Sci 2023;7(1):10.\u003c/li\u003e\n \u003cli\u003eMoher D, Hopewell S, Schulz KF, Montori V, G\u0026oslash;tzsche PC, Devereaux PJ, Elbourne D, Egger M, Altman DG. CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. Bmj 2010;340:c869.\u003c/li\u003e\n \u003cli\u003eSaini HR, Tewari S, Sangwan P, Duhan J, Gupta A. Effect of different apical preparation sizes on outcome of primary endodontic treatment: a randomized controlled trial. J Endod 2012;38(10):1309-1315.\u003c/li\u003e\n \u003cli\u003eViechtbauer W, Smits L, Kotz D, Bud\u0026eacute; L, Spigt M, Serroyen J, Crutzen R. A simple formula for the calculation of sample size in pilot studies. J Clin Epidemiol 2015;68(11):1375-1379.\u003c/li\u003e\n \u003cli\u003eFerreira NS, Gollo EKF, Boscato N, Arias A, Silva E. Postoperative pain after root canal filling with different endodontic sealers: a randomized clinical trial. Braz Oral Res 2020;34:e069.\u003c/li\u003e\n \u003cli\u003eMannocci F, Bhuva B, Roig M, Zarow M, Bitter K. European Society of Endodontology position statement: The restoration of root filled teeth. Int Endod J 2021;54(11):1974-1981.\u003c/li\u003e\n \u003cli\u003eSjogren U, Hagglund B, Sundqvist G, Wing K. Factors affecting the long-term results of endodontic treatment. J Endod 1990;16(10):498-504.\u003c/li\u003e\n \u003cli\u003eOrstavik D, Kerekes K, Eriksen HM. The periapical index: a scoring system for radiographic assessment of apical periodontitis. Endod Dent Traumatol 1986;2(1):20-34.\u003c/li\u003e\n \u003cli\u003eOrstavik D. Time-course and risk analyses of the development and healing of chronic apical periodontitis in man. Int Endod J 1996;29(3):150-155.\u003c/li\u003e\n \u003cli\u003eChybowski EA, Glickman GN, Patel Y, Fleury A, Solomon E, He J. Clinical Outcome of Non-Surgical Root Canal Treatment Using a Single-cone Technique with Endosequence Bioceramic Sealer: A Retrospective Analysis. J Endod 2018;44(6):941-945.\u003c/li\u003e\n \u003cli\u003eCoşar M, Kandemir Demirci G, \u0026Ccedil;alışkan MK. The effect of two different root canal sealers on treatment outcome and post-obturation pain in single-visit root canal treatment: A prospective randomized clinical trial. Int Endod J 2023;56(3):318-330.\u003c/li\u003e\n \u003cli\u003eLakens D. Equivalence Tests: A Practical Primer for t Tests, Correlations, and Meta-Analyses. Soc Psychol Personal Sci 2017;8(4):355-362.\u003c/li\u003e\n \u003cli\u003eHasheminia SM, Farhad AR, Saatchi M, Nejad HS, Sanei M. Mechanical or cold lateral compaction: The incidence of dentinal defects. Dent Res J (Isfahan) 2015;12(6):513-519.\u003c/li\u003e\n \u003cli\u003eChellapilla PK, Boddeda MR, Jyothi M, Uppalapati LV, Konagala RK, Dasari L. Influence of obturating techniques on root dentin crack propagation: A micro-computed tomography assessment. J Conserv Dent 2021;24(1):72-76.\u003c/li\u003e\n \u003cli\u003ePirani C, Zamparini F, Peters OA, Iacono F, Gatto MR, Generali L, Gandolfi MG, Prati C. The fate of root canals obturated with Thermafil: 10-year data for patients treated in a master\u0026apos;s program. Clin Oral Investig 2019;23(8):3367-3377.\u003c/li\u003e\n \u003cli\u003ePirani C, Friedman S, Gatto MR, Iacono F, Tinarelli V, Gandolfi MG, Prati C. Survival and periapical health after root canal treatment with carrier-based root fillings: five-year retrospective assessment. Int Endod J 2018;51 Suppl 3:e178-e188.\u003c/li\u003e\n \u003cli\u003eCamilleri J. Sealers and warm gutta-percha obturation techniques. J Endod 2015;41(1):72-78.\u003c/li\u003e\n \u003cli\u003eIglecias EF, Freire LG, de Miranda Candeiro GT, Dos Santos M, Antoniazzi JH, Gavini G. Presence of Voids after Continuous Wave of Condensation and Single-cone Obturation in Mandibular Molars: A Micro-computed Tomography Analysis. J Endod 2017;43(4):638-642.\u003c/li\u003e\n \u003cli\u003eChew ST, Eshak Z, Al-Haddad A. Evaluation of interfacial adaptation and penetration of bioceramic-based sealers in oval root canals: A confocal laser scanning microscope study. Microsc Res Tech 2023;86(7):754-761.\u003c/li\u003e\n \u003cli\u003eTajonar R, S\u0026aacute;nchez-Mendieta KP, Mart\u0026iacute;nez-Mart\u0026iacute;nez RE, Dom\u0026iacute;nguez-P\u0026eacute;rez RA. Periapical Healing of Endodontically Treated Teeth Filled Only in the Apical Third: A Randomized Controlled Trial. Eur Endod J 2018;3(1):24-30.\u003c/li\u003e\n \u003cli\u003eAlenezi MA, Al-Nazhan SA, Al-Omari MA. Three-dimensional evaluation of root canal morphology of maxillary first premolars: Micro-computed tomographic study. Saudi Dent J 2022;34(7):611-616.\u003c/li\u003e\n \u003cli\u003eHabib AA, Doumani MD, Nassani MZ, Shamsy E, Jto BS, Arwadİ HA, Mohamed SA. Radiographic Assessment of the Quality of Root Canal Fillings Performed by Senior Dental Students. Eur Endod J 2018;3(2):101-106.\u003c/li\u003e\n \u003cli\u003eWuersching SN, Diegritz C, Hickel R, Huth KC, Kollmuss M. A comprehensive in vitro comparison of the biological and physicochemical properties of bioactive root canal sealers. Clin Oral Investig 2022;26(10):6209-6222.\u003c/li\u003e\n \u003cli\u003eFerreira GC, Pinheiro LS, Nunes JS, de Almeida Mendes R, Schuster CD, Soares RG, Kopper PMP, de Figueiredo JAP, Grecca FS. Evaluation of the biological and physicochemical properties of calcium silicate-based and epoxy resin-based root canal sealers. J Biomed Mater Res B Appl Biomater 2022;110(6):1344-1353.\u003c/li\u003e\n \u003cli\u003eSathorn C, Parashos P, Messer H. The prevalence of postoperative pain and flare-up in single- and multiple-visit endodontic treatment: a systematic review. Int Endod J 2008;41(2):91-99.\u003c/li\u003e\n \u003cli\u003ePak JG, White SN. Pain prevalence and severity before, during, and after root canal treatment: a systematic review. J Endod 2011;37(4):429-438.\u003c/li\u003e\n \u003cli\u003eAl\u0026iacute; A, Olivieri JG, Duran-Sindreu F, Abella F, Roig M, Garc\u0026iacute;a-Font M. Influence of preoperative pain intensity on postoperative pain after root canal treatment: A prospective clinical study. J Dent 2016;45:39-42.\u003c/li\u003e\n \u003cli\u003eWang C, Xu P, Ren L, Dong G, Ye L. Comparison of post-obturation pain experience following one-visit and two-visit root canal treatment on teeth with vital pulps: a randomized controlled trial. Int Endod J 2010;43(8):692-697.\u003c/li\u003e\n \u003cli\u003eRuparel NB, Ruparel SB, Chen PB, Ishikawa B, Diogenes A. Direct effect of endodontic sealers on trigeminal neuronal activity. J Endod 2014;40(5):683-687.\u003c/li\u003e\n \u003cli\u003eSeron MA, Nunes GP, Ferrisse TM, Strazzi-Sahyon HB, Victorino FR, Dos Santos PH, Gomes-Filho JE, Cintra LTA, Sivieri-Araujo G. Postoperative pain after root canal filling with bioceramic sealers: a systematic review and meta-analysis of randomized clinical trials. Odontology 2023;111(4):793-812.\u003c/li\u003e\n \u003cli\u003eYu YH, Kushnir L, Kohli M, Karabucak B. Comparing the incidence of postoperative pain after root canal filling with warm vertical obturation with resin-based sealer and sealer-based obturation with calcium silicate-based sealer: a prospective clinical trial. Clin Oral Investig 2021;25(8):5033-5042.\u003c/li\u003e\n \u003cli\u003eAlzoubi F, Alajmi S, Alkandari A, Alqahtani S, Alanezi A, Setzer FC. Post-operative pain in non-surgical root canal treatment after sealer-based obturation versus warm vertical compaction: A randomized clinical trial. Int Endod J 2024;57(9):1168-1179.\u003c/li\u003e\n \u003cli\u003eGraunaite I, Skucaite N, Lodiene G, Agentiene I, Machiulskiene V. Effect of Resin-based and Bioceramic Root Canal Sealers on Postoperative Pain: A Split-mouth Randomized Controlled Trial. J Endod 2018;44(5):689-693.\u003c/li\u003e\n \u003cli\u003ede Melo Nunes R, Martins MR, da Silva Junior FS, de Melo Leite AC, Gir\u0026atilde;o VC, de Queiroz Cunha F, Marinho AL, Pinto AC, Rocha FA. Strontium ranelate analgesia in arthritis models is associated to decreased cytokine release and opioid-dependent mechanisms. Inflamm Res 2015;64(10):781-787.\u003c/li\u003e\n \u003cli\u003eRadwanski M, Pietrzycka K, Ey\u0026uuml;boğlu TF, \u0026Ouml;zcan M, Lukomska-Szymanska M. Clinical outcome of non-surgical root canal treatment using different sealers and techniques of obturation in 237 patients: A retrospective study. Clin Oral Investig 2024;28(9):479.\u003c/li\u003e\n \u003cli\u003eLi J, Chen L, Zeng C, Liu Y, Gong Q, Jiang H. Clinical outcome of bioceramic sealer iRoot SP extrusion in root canal treatment: a retrospective analysis. Head Face Med 2022;18(1):28.\u003c/li\u003e\n \u003cli\u003eRutz da Silva F, Padilha EZ, C\u0026acirc;ndido VS, Cavassim R, Pereira AC, Hebling E. Relationship between quality of root canal obturation and periapical lesion in elderly patients: a systematic review. Gerodontology 2016;33(3):290-298.\u003c/li\u003e\n \u003cli\u003eHuang D, Wang X, Liang J, Ling J, Bian Z, Yu Q, Hou B, Chen X, Li J, Ye L, Cheng L, Xu X, Hu T, Wu H, Guo B, Su Q, Chen Z, Qiu L, Chen W, Wei X, Huang Z, Yu J, Lin Z, Zhang Q, Yang D, Zhao J, Pan S, Yang J, Wu J, Pan Y, Xie X, Deng S, Huang X, Zhang L, Yue L, Zhou X. Expert consensus on difficulty assessment of endodontic therapy. Int J Oral Sci 2024;16(1):22.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Bioceramic-based sealers, clinical trial, endodontic outcomes, obturation technique, postoperative pain","lastPublishedDoi":"10.21203/rs.3.rs-5548977/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5548977/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e To evaluate the clinical efficacy and outcomes of C-Root SP bioceramic-based sealers combined with different obturation techniques in nonsurgical root canal treatment for older patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods \u003c/strong\u003eThis prospective, single-center, single-blind, parallel, randomized clinical trial included 240 patients aged ≥60 years. Patients were randomly divided into fourtreatment groups. Group A: C-Root SP combined with single-cone (SC); Group B: C-Root SP combined with warm vertical compaction (WVC); Group C: C-Root SP combined with cold lateral condensation (CLC); Group D: iRoot SP combined with SC (Control). All teeth were subjected to root canal filling using the corresponding methods 7–10 days after root canal preparation and medication. The duration of obturation was recorded. Periapical radiographs were obtained immediately after obturation to determine the length of root canal filling, and postoperative pain on days 1, 2, and 7 was documented. The treatment outcomes based on clinical signs and symptoms as well as periapical index (PAI) were analyzed at 1 year postoperatively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e Groups A and D exhibited significantly higher filling efficiency than groups B and C (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001). No significant differences were observed in the length of obturation between the groups (\u003cem\u003eP\u003c/em\u003e \u0026gt; 0.05). Postoperative pain decreased over time in all groups, with group A showing significantly lower pain rates on day 1 than the other groups (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05). After 1 year, all groups exhibited considerable reductions in the PAI scores, with success rates ranging from 91.23% to 94.83%; however, no significant differences were observed between them (\u003cem\u003eP\u003c/em\u003e \u0026gt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e C-Root SP combined with different obturation techniques yielded similar outcomes to iRoot SP combined with the SC technique in terms of filling length, success rate, and changes in PAI scores. The SC technique demonstrated significant advantages in terms of clinical efficiency and may reduce early postoperative pain when combined with C-Root SP.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration \u003c/strong\u003eThe study was retrospectively registered in chictr.org.cn with the identifier: ChiCTR2400092580 on 11/19/2024.\u003c/p\u003e","manuscriptTitle":"Clinical outcomes of nonsurgical root canal treatment using C-Root SP combined with different obturation techniques in older patients: a randomized controlled clinical trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-06 09:21:38","doi":"10.21203/rs.3.rs-5548977/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accepted","date":"2025-05-05T13:30:35+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-03T09:43:51+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Oral Health","date":"2025-04-28T13:45:05+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d2e24637-9cab-4af1-8547-ce3747136f2b","owner":[],"postedDate":"May 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-05-19T16:03:03+00:00","versionOfRecord":{"articleIdentity":"rs-5548977","link":"https://doi.org/10.1186/s12903-025-06117-9","journal":{"identity":"bmc-oral-health","isVorOnly":false,"title":"BMC Oral Health"},"publishedOn":"2025-05-15 15:58:11","publishedOnDateReadable":"May 15th, 2025"},"versionCreatedAt":"2025-05-06 09:21:38","video":"","vorDoi":"10.1186/s12903-025-06117-9","vorDoiUrl":"https://doi.org/10.1186/s12903-025-06117-9","workflowStages":[]},"version":"v1","identity":"rs-5548977","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5548977","identity":"rs-5548977","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}