Application of local melatonin for controlling peri-implantitis: a randomized clinical trial

Application of local melatonin for controlling peri-implantitis: a randomized 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 Application of local melatonin for controlling peri-implantitis: a randomized clinical trial Carlos Manuel Cobo-Vázquez, Pedro Molinero-Mourelle, Cristina Madrigal-Martínez-Pereda, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7095643/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objectives : The main objective was to determine the effectiveness of melatonin in the treatment of peri-implantitis. Secondary objectives were to determine the anti-inflammatory, osteogenic and antimicrobial properties of melatonin. Materials and Methods : A randomized clinical trial was carried out in patients affected by peri-implantitis with a follow-up of 60 days. Melatonin 1.9 mg or placebo was applied locally to the peri-implant defect after debridement. The probing depth, bleeding index, plaque index, and interleukin-1β and 6 concentrations, peri-implant bone level and the bacterial strains were analyzed. Results : 30 patients were analyzed with a mean age of 71.9±7.3 years. Changes on the probing depth in the melatonin group were -1.80±0.88 mm and -1.38±0.47 mm in placebo. Bone level changes were -0.87±0.74 mm in the melatonin group and -0.80±0.68 mm in the placebo. The interleukin-1β concentration at 60 days was 8.62±5.09 pg/mL in the melatonin group and 9.07±5.57 pg/mL in placebo. No differences were observed in probing depth (p=.17), plaque index (p=.57), bleeding index (p=.91), peri-implant bone level (p=.43), interleukin-1β (p=.80), interleukin-6 (p=.52) and anaerobic bacterial species (p=0.96). There were differences in the P. gingivalis concentration (p=.05). Conclusions : Anti-inflammatory, analgesic, osteogenic and antimicrobial properties of melatonin cannot be determined. It seems to improve slightly probing depth changes, interleukin-1β levels and P. gingivalis concentration. Trial registration : Protocol Registration & Results System Clinical Trial Number NCT06816277- Clinical Relevance: Melatonin could improve plaque index, bleeding index, reduce probing depth and peri-implant marginal bone loss, in addition to controlling certain bacterial species in the short term. melatonin periimplant disease marginal bone loss inflammation treatment Figures Figure 1 Figure 2 Figure 3 BACKGROUND Peri-implant diseases are a host response to the formation of a biofilm on the implant surface. They are initiated by inflammatory reactions with an increase in interleukins (IL-1, IL-6, IL-8 and IL-17) produced by bacterial species in the soft tissue surrounding the implant and can subsequently lead to loss of bone support [ 1 , 2 ]. According to the Sixth European Consensus of Periodontology (2008) its incidence is between 28–56%. Although the etiology of these diseases is not clear, the increased presence of gram-negative microorganisms and spirochetes has been determined [ 3 ]. It is known that the increase in IL-6 in the injured area triggers the production of the first symptoms of inflammation and stimulates bone resorption in the initial stages of osteoclastogenesis [ 2 ]. Treatment protocols for peri-implant diseases are not established and have limitations when there is peri-implant bone loss. Due to the importance of periodontal therapy, several authors propose the investigation of anti-inflammatory and preventive agents such as melatonin, using this molecule as complementary therapeutic strategies in models of periodontal disease [ 3 ]. Melatonin (N-acetyl-5-methoxytryptamine) is a highly lipophilic pleiotropic hormone synthesized mainly in the pineal gland. Its therapeutic applications derive from its two main properties, its high antioxidant power and its great lipid solubility [ 4 ]. Due to these properties, it has been used successfully after oral surgery, with stimulating and protective effects on the intracellular enzymes involved in the healing process, inhibiting the production of prostaglandins, TNF-α, and interleukins (IL-1β, IL-6, IL-8 and IL-10) [ 5 , 10 ]. Several studies have confirmed the anti-inflammatory activity produced by melatonin in situations of acute inflammation and exacerbated immune response [ 8 , 9 , 11 – 13 ]. On the contrary, other studies have shown that exogenous administration of melatonin above the body's basal levels stimulates the immune system by increasing the proliferation of T lymphocytes, NK cells and granulocytes, and the antibody response [ 14 – 17 ]. T cell activation increases the release of inflammatory cytokines such as interferon-ɣ, TNF-α, IL-1, IL-1β, IL-2, IL-6, and IL-12. The stimulation of the immune and inflammatory system depends on the concentration of melatonin, which is responsible for the inflammatory response and the body's defense against bacterial and viral infections [ 18 – 21 ]. Melatonin has been used in bone formation and the stimulation of bone metabolism [ 17 , 22 , 23 ]. In osseointegrated implants, earlier osteoblast differentiation, an increase in osteoblast proliferation and an acceleration in the synthesis and mineralization of the osteoid matrix have been observed after 2 weeks and 4 weeks of implant placement, as well as a significant increase in the width and length of cortical bone [ 17 , 24 , 25 ]. In histological analysis, the local application of melatonin has been shown to increase trabecular formation by directly stimulating osteoblasts from the endosteum [ 26 , 27 ]. Furthermore, it has been described a slight increase in radiological bone density at 15 days without relevant inflammatory phenomena at a macroscopic level. However, no differences with untreated bone in imaging or microscopic tests at 60 days were found, behaving as a biomimetic agent, with anti-inflammatory and osteogenic properties [ 27 ]. The effectiveness of melatonin in restricting the survival and growth of bacteria is explained by its diffusion properties through the bacterial cell wall and its ability to reduce the levels of lipids present in cell membranes. Gram-negative bacteria have an internal and external cell membrane composed of glycopeptide proteins, lipopolysaccharides and large amounts of lipids, which explains that the antimicrobial activity of melatonin is greater in these bacteria. Furthermore, bacteria are highly dependent on free metals for their growth, particularly iron. Once in the cytoplasm, melatonin binds iron (III), copper and zinc, thus reducing their cytoplasmic availability due to its high metal binding capacity. This mechanism is of special relevance in an infected environment in an environment with metals, such as peri-implant infections. Peri-implant bone loss is established and progresses due to oxidative stress processes produced by oral biofilm, which activate osteoclasts directly, and by the indirect destruction of membrane lipids and collagen fibers produced by activated polymorphonuclear cells [ 28 ]. Proinflammatory cytokines, such as TNFα, a granulocyte and macrophage-stimulating factor (IL-1, IL-6, and IL-8), and lipopolysaccharide, among others, also stimulate polymorphonuclear cells to produce higher levels of oxidative stress [ 28 ]. The main objective of the present research is to determine the effectiveness of melatonin in the treatment of peri-implant diseases. The secondary objectives are to determine the anti-inflammatory, osteogenic and bactericidal properties of melatonin. METHODS This Randomized Clinical Trial was carried out following the recommendations of the Consolidated Standards Of Reporting Trials Declaration (CONSORT 2010), the requirements established in the Declaration of Helsinki (World Medical Assembly), and in accordance with the Data Protection Law (the Organic Law 3/2018, of December 5, on Protection of Personal Data and guarantee of digital rights). The protocol was approved by the Clinical Research Ethics Committee (CEIC) of the San Carlos Clinical Hospital of Madrid, minute 7.2/19; C.P. MEL19 - C.I. 19/313-E. In Spain, the Spanish Agency for Medicines and Health Products (AEMPS), dependent on the Ministry of Health, establishes that the use of melatonin in doses greater than 1.9 mg was only possible under medical prescription for the treatment of sleep disorders and hyperactivity disorders, or autism spectrum (Royal Legislative Decree 1/2015), which is why it is only marketed in Spain in doses less than 2 mg. Recruitment Volunteer participants diagnosed with peri-implant disease were recruited according to the criteria of the Classification of Periodontal and Peri-implant Diseases and Conditions of the 2017 World Workshop, with an indication for peri-implant surgical treatment, with one or more fully erupted teeth. Patients of both sexes were included, aged between 40 and 85 years, in healthy condition (Category I and II of the American Society of Anesthesiologists [ASA]), with no history or metabolic or systemic diseases that affected the bone or the healing process. as is the case of diabetes, without autoimmune diseases, coagulation or healing disorders and who, meeting the inclusion criteria, agreed to sign the informed consent. Exclusion criteria were established as tobacco consumption > 25 cigarettes a day, the use of hormonal, anti-inflammatory, corticosteroids, immunosuppressants, analgesics, antidiabetic or antiresorptive medications on a regular or recent basis, pregnant or breastfeeding women, and those who refused to participate in the study or did not allow follow-up and sample collection. Study design The implant with the most severe involvement was selected, although the treatment was performed on all implants, to prevent patients with more affected implants from having greater statistical relevance. Prior to treatment (T0), the peri-implant clinical and radiological study was carried out using periapical radiography with a parallelize and samples of crevicular fluid from the implant were obtained in duplicate. The peri-implant surgical treatment was performed under local infiltrative anesthesia with 4% articaine with 1:100,000 adrenaline. Debridement was performed using ultrasound with irrigation, complemented using curettes. Treatment with melatonin or placebo was applied through computer block randomization. To achieve blinding, a different code was assigned to the group applying 1.9 mg of melatonin (A) and to the control group (B) applying placebo (dextrinomaltose 2 mg) powder and the samples and records were coded. It was sutured with 4/0 monofilament in a pre-assembled 3/8 semicircular needle (Fig. 1 ). In all patients, 1000 mg of Paracetamol was prescribed every 8 hours in case of pain, and it was indicated not to rinse or use any topical antiseptic. At 7 days (T1), the healing process was reviewed, sutures were removed, and crevicular fluid samples were taken. At 21 days (T2), a new complete peri-implant registration, new crevicular fluid samples and a radiological study were performed. At 60 days (T3), a new complete peri-implant registration, crevicular fluid samples and radiological study were performed. To detect the appearance of complications, a record of adverse events was established for a period of two months after treatment. Variables Probing depth The distance from the gingival margin to the bottom of the periodontal pocket was considered. The measurement was carried out in the four locations surrounding the implant, mesial, distal, lingual and vestibular. Additionally, the average of the four locations was presented. Plaque Index (Löe y Silness) The presence of visible bacterial plaque was considered adapted to rehabilitation using implants (Grade 0: No plaque; Grade 1: No plaque with the naked eye. There is plaque when the exploration is performed with a probe in the peri-implant area; Grade 2: There is visible bacterial plaque; Grade 3: There is visible bacterial plaque surrounding the implant, including interdental spaces. There may be stones. Adequate plaque control is considered to exist when the index results in a value ≤ 1. Bleeding Index (Löe y Silness) It was considered during the 30 seconds after probing adapted to the implant model (Grade 0: Absence of bleeding; Grade 1: A spot of blood does not appear until a few seconds after probing; Grade 2: Bleeding immediately after of probing; Grade 3: Bleeding at the slightest contact with the mucosa, extension of bleeding along the sulcus). Marginal bone loss The evaluation of the peri-implant-crestal bone level was performed using the ImageJ® program (NIH, Bethesda, MD, USA). From the measurement in pixels of the known length of the implant, the vertical measurement of the bone level was determined from the implant platform and perpendicular to it, to the area of ​​turbinate bone in contact with the surface of the implant both mesial and distal. It was considered as a single measurement of the mesial and distal mean of each implant considering the clinical significance (Fig. 2 ). IL-1β and IL-6 concentration Crevicular fluid samples obtained using Perio-paper strips were analyzed with the enzyme-linked immunosorbent assay (ELISA) technique. The samples were stored in sterile 13x75mm x 2 mL BD Vacutainer® tubes and were processed using the ELH-IL1B-1 Human IL-1 beta ELISA Kits 1 x 96-Wel BIONOVA CIENTIFICA S.L and HEA079HU-48T High Sensitive ELISA Kit for Interleukin 6 (IL-6) 48T BIONOVA CIENTIFICA SL for analysis of interleukin-1β and 6 at 60–90 minutes after obtaining it. The determinations were read using the ELISA reader (Ivymen System 2100-C). The standard curve of the kits was made in duplicate for IL-1β and IL-6 both in the test and in the total analysis of the samples. Microbiological count A Colon Forming Unit (CFU) count was performed on the crevicular fluid samples obtained using sterile paper points. They were transferred into a vial of reduced transport liquid with 1.0 mL of RTF transport medium to preserve the anaerobiosis of the samples for 24 hours and quantify the sample volume. The samples were immediately cultured on blood agar medium and the peri-implantopathogenic, periodontopathogenic and candida species were identified. Sample size calculation The calculation of the sample size was carried out taking as reference previous similar studies [ 34 , 37 ]. 30 patients (15/15) were considered to detect differences with a large effect size (d = 1) and with a statistical power of 80%. Considering a possible drop out of patients, a minimum recruitment of 33 patients was estimated. Statistical analysis A descriptive analysis of the most relevant statistics was carried out for all the variables collected in the research: absolute and relative frequencies (for the categorical ones) and mean, standard deviation, range, median and 25th and 75th percentiles (for the continuous ones). The Shapiro-Wilk test was applied to evaluate the adjustment to a normal distribution of the variables in both groups. To carry out the inferential analysis, the non-parametric Brunner-Langer Model for longitudinal data was used. To study the evolution of the different variables (clinical, inflammatory, microbiological) throughout all measurements of the period depended on the type of treatment. A level of statistical significance p ≤ 0.05 was established. RESULTS 41 participants were recruited consecutively, of which 11 participants were excluded. A final sample of 30 patients was analyzed, 10 men (33.3%) and 20 women (66.7%), with a mean age of 71.9 ± 7.3 years (48–85 years) (Fig. 3 ). The results of the homogeneity tests showed that the groups were homogeneous, and the variables were not potential confounders (Table 1 ). Table 1 Tests of homogeneity of treatment groups according to independent variables Chi2 Test and Mann-Whitney test p-value SEX 0.439 (Chi 2 ) AGE 0.838 (MW) SMOKERS 0.682 (Fis) DISEASES 0.464 (Chi 2 ) DYSLIPEMIA 1.000 (Fis) HIGH BLOOD PRESSURE 0.705 (Chi 2 ) ANEMIA 1.000 (Fis) DIABETES 0.483 (Fis) HYPOTIROIDISM 0.483 (Fis) TOOTH TYPE 0.587 (Chi 2 ) ARCH 0.705 (Chi 2 ) BRAND 0.502 (Chi 2 ) RESTORATION TYPE 0.140 (Chi 2 ) *p<0.05; **p<0.01; ***p<0.001 The evolution of the vestibular, palatal, mesial, distal and average probing depth between both groups (interaction effect) determined that both treatments produced a significant decrease throughout the follow-up (p < 0.001). There were no statistically significant differences in probing depth levels in any location according to the type of treatment. No differences were observed in the average probing depth level depending on the treatment applied (A or B) (p = 0.170). After the analysis, a reduction in probing depth was observed in group A of 1.80 mm and in group B of 1.38 mm at 60 days (Table 2 ). This is a lower effect size (d = 0.5) than that proposed in the statistical power calculation prior to the study and explains why we did not find statistically significant differences (p = 0.307). Table 2 Descriptive values ​​of the mean peri-implant probing depth throughout the follow-up according to groups GROUP Total Melatonin Placebo PSmeanT0 N 30 15 15 Mean 5,46 5,78 5,13 Standard deviation 1,07 1,15 ,91 Minimum 3,25 4,00 3,25 Maximum 7,75 7,75 6,25 25th percentile 5,00 5,00 4,25 Median 5,50 5,50 5,50 75th percentile 6,00 7,00 5,75 PSmeanT2 N 30 15 15 Mean 4,24 4,53 3,95 Standard deviation ,76 ,77 ,65 Minimum 3,00 3,50 3,00 Maximum 6,00 6,00 4,75 25th percentile 4,00 4,00 3,00 Median 4,25 4,25 4,25 75th percentile 4,75 5,00 4,50 PSmeanT3 N 30 15 15 Mean 3,87 3,98 3,75 Standard deviation ,71 ,72 ,71 Minimum 2,50 3,00 2,50 Maximum 5,50 5,50 4,75 25th percentile 3,25 3,25 3,00 Median 4,00 4,00 4,00 75th percentile 4,25 4,25 4,50 Both treatments produced a significant decrease in the plaque index throughout the follow-up time (p < 0.001). The level of plaque index is significantly higher in group A than in B (p < 0.001). No significant interaction is observed (p = 0.568). That is, the evolution of the plaque index is similar in both groups over time. Therefore, the progression of the plaque index in group A can be extrapolated to any time and does not present differences compared to group B (Table 3 ). Table 3 Descriptive blues of the Plaque Index throughout the follow-up according to groups. GROUP Total Melatonin Placebo IP T0 N 30 15 15 Mean 1,90 2,07 1,73 Standard deviation ,48 ,46 ,46 Minimum 1,00 1,00 1,00 Maximum 3,00 3,00 2,00 25th percentile 2,00 2,00 1,00 Median 2,00 2,00 2,00 75th percentile 2,00 2,00 2,00 IP T2 N 30 15 15 Mean ,30 ,53 ,07 Standard deviation ,53 ,64 ,26 Minimum ,00 ,00 ,00 Maximum 2,00 2,00 1,00 25th percentile ,00 ,00 ,00 Median ,00 ,00 ,00 75th percentile 1,00 1,00 ,00 IP T3 N 30 15 15 Mean ,63 ,80 ,47 Standard deviation ,56 ,41 ,64 Minimum ,00 ,00 ,00 Maximum 2,00 1,00 2,00 25th percentile ,00 1,00 ,00 Median 1,00 1,00 ,00 75th percentile 1,00 1,00 1,00 Both treatments produced a significant decrease in the Bleeding Index throughout the follow-up (p < 0.001). The Bleeding Index level is globally similar between groups (p = 0.298). Bleeding control is comparable between both treatments, with no statistically significant differences between both (p = 0.910). Both melatonin treatment and placebo produce a significant decrease in marginal bone loss throughout follow-up (p < 0.001). The level of marginal bone loss is somewhat higher, with more negative values, in group A compared to group B (p = 0.051). However, the evolution of marginal bone loss was statistically similar between both groups (p = 0.431) (Table 4 ). Table 4 Descriptive values ​​of the mean marginal bone loss throughout the follow-up according to groups GROUP Total Melatonin Placebo MBL T0 N 30 15 15 Mean -4,43 -4,87 -4,00 Standard deviation 1,17 1,25 ,93 Minimum -6,00 -6,00 -6,00 Maximum -3,00 -3,00 -3,00 25th percentile -6,00 -6,00 -5,00 Median -4,00 -5,00 -4,00 75th percentile -3,00 -4,00 -3,00 MBL T2 N 30 15 15 Mean -4,20 -4,47 -3,93 Standard deviation 1,03 1,06 ,96 Minimum -6,00 -6,00 -6,00 Maximum -3,00 -3,00 -3,00 25th percentile -5,00 -5,00 -5,00 Median -4,00 -4,00 -4,00 75th percentile -3,00 -4,00 -3,00 MBL T3 N 30 15 15 Mean -3,60 -4,00 -3,20 Standard deviation 1,04 ,93 1,01 Minimum -5,00 -5,00 -5,00 Maximum -2,00 -2,00 -2,00 25th percentile -4,00 -5,00 -4,00 Median -4,00 -4,00 -3,00 75th percentile -3,00 -3,00 -2,00 The concentration of IL-1β presents significant variations throughout the follow-up (p = 0.010). There were no statistically significant differences in IL-1β levels according to the type of treatment (p = 0.804). This behavior can be extrapolated to any of the treatments (p = 0.555). It should be noted that at time T3 (60 days) the medians are practically the same in both groups (8.3 pg/mL) and so are the global variations T3-T0 (0 pg/mL). At 7 days, both groups presented uniform values, with little variability except for atypical cases. At 21 days the range of possible values ​​amplifies again and remains this way until 60 days. The statistical results of the model concluded that the treatments produce a significant increase in IL-6 throughout the follow-up (p < 0.001). There is no effect dependent on the study group. The increase in IL-6 presents a similar pattern in both groups with no statistically significant differences between them (p = 0.515). It should be noted that at time T3 (60 days) the medians are 0.19 and 0.16 pg/mL in treatment A and B respectively. The overall T3-T0 change was, respectively, 0.15 and 0.13 pg/mL. The initial total anaerobic bacteria count in the melatonin group was 2,156,933.3 ± 2,000,755.1 CFU/mL and in the placebo group was 3,545,333.3 ± 2,330,973.5 CFU/mL. At 60 days, 1,841,446.7 ± 2,161,934.9 CFU/mL and 2,137,800.0 ± 2,482,920.8 CFU/mL were found, respectively. Regarding the total number of anaerobic species, no statistically significant differences were observed in terms of their count throughout the follow-up (p = 0.328). There were also no statistically significant differences in the treatment group. Stability was applicable to both groups and without statistically significant differences between the groups (p = 0.959). Changes in the amount of Porphyromona gingivalis depended specifically on the type of treatment (p = 0.046). For each treatment there is a notable oscillation in the charge of this bacteria and this pattern of charge oscillation is antagonistic. The amount of Prevotella intermedia detected changes significantly in the study period (p = 0.013). This change is statistically similar in both groups, with no statistically significant differences between treatment and placebo (p = 0.599). The amount of Fusobacterium nucleatum remains stable over time (p = 0.154). The bacterial load of Fusobacterium nucleatum in the placebo group is higher than in melatonin group (p = 0.039). This statement includes time T0, so it cannot be an effect attributable to the treatment. A similar longitudinal pattern of bacterial load is found in both treatment groups (p = 0.125). DISCUSSION The conventional treatment of peri-implant pathologies has demonstrated limited effectiveness, which is why the need for bioactive molecules has been proposed. The described biological properties of melatonin have placed this molecule as an alternative that deserves consideration in implant dentistry [ 29 – 31 ]. There are no clinical trials in humans in the literature that treat peri-implant disease states with bone loss through the local application of melatonin. Therefore, the different doses, routes of administration and type of pathology make comparison with the present clinical trial difficult, in addition to the use of other topical antiseptics in most previous studies. In the present study, the reduction in the average probing depth in the melatonin group (1.80 ± 0.88 mm) does not present statistical differences compared to the control group (1.38 ± 0.47 mm), although it can be verified that there is an improvement in probing depth in all locations in both groups. This improvement is most noticeable at 21 days and remains stable at 60 days. The initial plaque index values ​​in both groups correspond to states of poor plaque control by the patient. Higher values ​​were recorded in the melatonin group throughout all phases of the study, which could be related to a worse outcome of the peri-implant treatment. However, the results are not worse compared to the control. The initial mean bleeding index for both groups correspond to peri-implant disease states. At the end of the follow-up time, improvement was found, with a reduction in the bleeding index of 1.67 ± 0.49 for the melatonin group and 1.60 ± 0.51 for the control group. There are some studies that compare periodontal clinical parameters such as probing depth, plaque index and bleeding index in groups of patients with periodontal disease to whom melatonin is applied [ 35 – 37 ]. Authors such as Tinto et al. [ 32 ], Chitsazi et al. [ 33 ], Cutando et al. [ 34 ], and Anton et al. [ 35 ] found favorable differences in terms of probing depth in periodontal disease by supplying 1 mg of melatonin daily orally for 4 weeks, 2 mg daily orally for 4 weeks, 1% topically for 20 days and 3 mg orally daily for 2 months. On the other hand, El-Sharkawy et al. [ 36 ], using 10 mg daily orally for 2 months in the treatment of periodontal disease, found a decrease in plaque index values ​​from 2.35 ± 0.45 to 0.84. ± 0.26 at 3 months and the bleeding index from 2.14 ± 0.36 to 0.73 ± 0.19, although without statistically significant differences. The only periodontal parameter that registers significant differences compared to the control is the probing depth, evolving from 4.3 ± 0.8 mm to 2.4 ± 1.0 mm. The study by Ahmed et al. [ 37 ] evaluates the effect of 5% melatonin gel administered locally as a complement to non-surgical periodontal therapy in patients with stage II periodontitis in terms of probing depth, clinical insertion level, plaque index, and bleeding index at 3 months. Their results agree with the study by Montero et al. [ 38 ], which reported that topical application of melatonin has positive effects on periodontal health and resulted in a significant improvement in clinical parameters such as gingival index and probing depth [ 38 ]. Unlike the results described by previous studies, in the present investigation no statistically significant differences were found regarding treatment with melatonin. This could be due to the dose used and in a unique way that in other investigations was carried out continuously. The initial mean marginal bone loss corresponds to advanced peri-implant disease states, although a greater loss is seen in the melatonin group (-4.87 ± 1.25 mm) compared to the placebo (-4.00 ± 0.93 mm). At the end of the follow-up, a greater improvement was found in the melatonin group (0.87 ± 0.74 mm) compared to the control (0.80 ± 0.68 mm), which could be promising despite exhibiting a limited effect due to the advanced peri-implant disease. Most studies describe beneficial effects in controlling marginal bone loss and peri-implant bone density in topical use [ 39 , 40 ]. However, these studies include experimental studies [ 17 , 24 , 27 , 41 , 42 – 45 ], coating the implant [ 39 , 43 , 44 ] or injected around the implants. implants at the time of placement [ 41 ], so the results are not comparable. Its application in peri-implant bone regeneration with autologous bone shows favorable differences in terms of marginal bone loss, although they are not found in probing depth according to Hazzaa et al. [ 46 ]. The evolution of IL-1β concentration shows a decrease after 7 days in both groups, although initially the value in the melatonin group was higher (9.84 ± 5.47 pg/mL) and similar values ​​are reached in both groups. (6.80 ± 3.83 pg/mL vs 6.79 ± 4.20 pg/mL), but without differences between both groups. At 21 and 60 days it is observed that the concentration increases in both groups but in the melatonin group it maintains greater stability (8.37 ± 6.08 pg/mL and 8.62 ± 5.09 pg/mL) than in the group. placebo (7.27 ± 5.52 pg/mL and 9.07 ± 5.57 pg/mL). Regarding the concentration of IL-6, it experienced an increase after 7 days in both groups. At 21 days it is observed that the concentration decreases and at 60 days it increases again in a similar way in both groups. Authors such as Hazzaa et al. [ 46 ] found significant reductions in proinflammatory interleukins, such as TNF α, IL-6 and CRP after two months by providing 6 mg/day orally of melatonin as an adjuvant to periodontal therapy. The periodontal pathogens Porhyromona gingivalis, Prevotella intermedia, Tannerella forsythia and Fusobacterium nucleatum are the most frequently associated with peri-implantitis [ 47 – 52 ]. Several studies affirm that Fusobacterium species are found in the initial stages and their increase is related to a greater severity of peri-implant disease [ 53 – 55 ]. P. gingivalis species and other strains are among the dominant bacterial species in advanced peri-implant diseases and failed implants. Coinfection with P. gingivalis and Fusobacterium has been shown to synergistically increase bone loss and exacerbate host inflammatory responses, being related with the progression of peri-implant clinical parameters [ 49 , 56 ]. Previous scientific evidence describes that melatonin exerts antibacterial activities on common gram-negative and positive bacteria. The direct actions of melatonin can occur only at very high concentrations, which is a limitation in terms of clinical applicability. However, other indirect mechanisms include the activation of host defense mechanisms or, in sepsis, the attenuation of bacteria-induced inflammation [ 57 ]. The binding of melatonin to free metals in the peri-implant environment may have favorable bacteriostatic properties, since bacterial growth is dependent on these metals [ 57 – 59 ]. The properties of melatonin against bacteria such as Porphyromonas gingivalis have been demonstrated in in vitro models [ 60 ]. Regarding the anaerobic bacterial species found in the present study, it seems that the application of melatonin does not present favorable differences compared to placebo in the total number of anaerobes. On Porphyromonas gingivalis counts, melatonin produces an antagonistic effect to that which occurs with placebo. This behavior should be studied in future research, since it does not correspond to the results of any previous study. A favorable effect of melatonin is found in terms of reducing Prevotella intermedia in the long term. The effects on Fusobacterium nucleatum do not present significant differences, although its behavior does not obey any pattern. Despite the limitations regarding the dose of melatonin applied according to the legislation in force at the time, it could be deduced from the results that the concentration is insufficient to produce significant direct effects. It should be considered that to observe direct effects in environments where there are bacteria that coexist with salivary melatonin, the administered dose should be much higher. Other limitations that must be considered are the patient's oral hygiene habits and local conditions such as the three-dimensional position of the implants, the thickness and characteristics of the peri-implant mucosa. Despite not finding statistically significant differences in the study variables based on applying melatonin versus a placebo, favorable changes are observed in the parameters evaluated over time. Its application could be favorable in improving the plaque index, bleeding index, reducing probing depth and peri-implant marginal bone loss, in addition to controlling certain bacterial species in the short term, such as Prevotella intermedia and Fusobacterium nucleatum, and in the long term like Porphyromona gingivalis. In conclusion, no significant differences were observed when using a placebo in terms of probing depth, Plaque Index, Bleeding Index, marginal bone loss, IL-1β and IL-6 levels, overall. of anaerobic species, Prevotella intermedia and Fusobacterium nucleatum throughout the follow-up. Differences were found in the count of Porphyromona gingivalis throughout the follow-up. No complications were recorded in any group throughout the study follow-up period. Despite not finding statistically significant differences in the study variables based on applying melatonin versus a placebo, favorable changes are observed in the parameters evaluated over time. For this reason, it would be advisable to carry out more research by increasing the applied dose of melatonin and the sample, with a similar methodology, to be able to establish the differences with the application of a placebo. Abbreviations AEMPS Spanish Agency for Medicines and Health Products ASA American Society of Anesthesiologists BOP Bleeding Rate CAL Clinical Attachment Loss CEIC Clinical Research Ethics Committee Cmax Maximum concentration CONSORT Consolidated Standards of Reporting Trials SD Standard Deviation ELISA Enzyme-linked immunosorbent assay IL Interleukin TNF Tumor Necrosis Factor Declarations ETHICS APPROVAL AND CONSENT TO PARTICIPATE The study was conducted in accordance with the requirements established in the Declaration of Helsinki (World Medical Assembly) and with the Data Protection Law (the Organic Law 3/2018, of December 5, on Protection of Personal Data and guarantee of digital rights). The protocol was approved by the Clinical Research Ethics Committee (CEIC) of the San Carlos Clinical Hospital of Madrid, dated 07/02/2019; C.P. MEL19 - C.I. 19/313-E. The informed consent for participants was obtained previously for all the participants. CONSENT FOR PUBLICATION Not applicable. AVAILABILITY OF DATA AND MATERIALS Data and materials are available at the Clinical Research Ethics Committee of the San Carlos Clinical Hospital of Madrid. COMPETING INTEREST All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript. FUNDING There was no funding. The authors did not receive support from any organization for the submitted work. AUTHORS CONTRIBUTIONS This Randomized Clinical Trial was carried out following the recommendations of the Consolidated Standards Of Reporting Trials Declaration (CONSORT 2010), the requirements established in the Declaration of Helsinki (World Medical Assembly), and in accordance with the Data Protection Law (the Organic Law 3/2018, of December 5, on Protection of Personal Data and guarantee of digital rights). The protocol was approved by the Clinical Research Ethics Committee (CEIC) of the San Carlos Clinical Hospital of Madrid, minute 7.2/19; C.P. MEL19 - C.I. 19/313-E. ACKNOWLEDGEMENTS Not applicable References Gazivoda D, Dzopalic T, Bozic B et al (2009) Production of proinflammatory and immunoregulatory cytokiness by inflammatory cells from periapical lesions in culture. J Oral Pathol Med 38:605 Hurst SM, Wilkinson TS, McLoughlin RM, Jones S, Horiuchi S, Yamamoto N et al (2001) IL-6 and its soluble receptor orchestrate a temporal switch in the pattern of leukocyte recruitment seen during acute inflammation.Immunity. 14:705–714 Karring ES, Stavropoulos A, Elleegaard B, Karring T (2005) Treatment of peri-implantitis by the Vector ® system. A pilot study. Clin Oral Implants Res 16(3):288–293 Tan DX, Reiter RJ, Manchester LC et al (2002) Chemical and physical properties and potential mechanisms: melatonin as a broad-spectrum antioxidant and free radical scavenger. Curr Top Med Chem 2:181 Cutando A, Aneiros-Fernández J, López-Valverde A et al (2011) A new perspective in oral health: potential importance and actions of melatonin receptors MT1, MT2, MT3, and RZR/ROR in the oral cavity. Arch Oral Biol 56:944 Pandi-Perumal SR, Srinivasan V, Maestroni GJM, Cardinali DP, Poeggeler B, Hardeland R (2006) Melatonin. Nature´s most versatile biological signal? FEBS J 273:2813–2838 Carrillo-Vico A, Calvo JR, Abreu P, Lardone PJ, Garcia- Maurino S, Reiter RJ, Guerrero JM (2004) Evidence of melatonin synthesis by human lymphocytes and its physiological significance: possible role as intracrine, autocrine, and⁄or paracrine substance. FASEB J 18:537–539 Ressmeyer AR, Mayo JC, Zelosko V, Sainz RM, Tan DX, Poeggeler B, Antolin I, Zsizsik BK, Reiter RJ, Hardeland R (2003) Antioxidant properties of the melatonin metabolite N1-acetyl-5-methoxykynuramine (AMK): scavenging of free radicals and prevention of protein destruction. Redox Rep 8:205–213 Reiter RJ, Tan DX, Manchester LC, Qi W (2001) Biochemical reactivity of melatonin with reactive oxygen and nitrogen species: a review of the evidence. Cell Biochem Biophys 34:237–256 Konturek SJ, Zayachkivska O, Havryluk XO, Brzozowski T, Sliwowski Z, Pawlik M et al (2007) Protective influence of melatonin against acute esophageal lesions involves prostaglandins, nitric oxide and sensory nerves. J Physiol Pharmacol 58(2):361–377 Radogna F, Diederich M, Ghibelli L (2010) Melatonin: a pleiotropic molecule regulating inflammation. Biochem Pharmacol 80:1844–1852 Cutando A, Arana C, Gomez G, Escames G, Lopez A, Ferrera MJ et al (2007) Local application of melatonin into alveolar sockets of beagle dogs reduces tooth removal-induced oxidative stress. J Periodontol 78:576–583 Carrillo-Vico A, Lardone PJ, Álvarez-Sánchez N (2013) Rodríguez-Rodríguez A and Guerrero JM. Melatonin: buffering the immune system. Int J Mol Sci 14:8638–8683 Xia MZ, Liang YL, Wang H, Chen X, Huang YY, Zhang ZH et al (2012) Melatonin modulates TLR4-mediated inflammatory genes through MyD88- and TRIF-dependent signaling pathways in lipopolysaccharide-stimulated RAW264.7 cells. J Pineal Res 53(4):325–334 Ahmad R, Haldar C, Gupta S (2012) Melatonin membrane receptor type mt1 modulates cell-mediated immunity in the seasonally breeding tropical rodent funambulus pennanti. Neuroimmunomodulation 19:50–59 Ahmad R, Haldar C (2010) Photoperiodic regulation of mt1 and mt2 melatonin receptor expression is spleen and thymus of a tropical rodent funambulus pennanti during reproductively active and inactive phases. Chronobiol Int 27:446–462 Cutando A, Gómez-Moreno G, Arana C, Muñoz F, Lopez-Peña M, Stephenson J et al (2008) Melatonin stimulates osteointegration of dental implants. J Pineal Res 45:174–179 Radogna F, Diederich M, Ghibelli L (2010) Melatonin: a pleiotropic molecule regulating inflammation. Biochem Pharmacol 80:1844–1852 Jimenez-Jorge S, Jimenez-Caliani AJ, Guerrero JM, Naranjo MC, Lardone PJ, Carrillo-Vico A, Osuna C, Molinero P (2005) Melatonin synthesis and melatonin-membrane receptor (mt1) expression during rat thymus development: Role of the pineal gland. J Pineal Res 39:77–83 Ahmad R, Haldar C (2010) Melatonin and androgen receptor expression interplay modulates cell-mediated immunity in tropical rodent funambulus pennanti: An in vivo and in vitro study. Scand J Immunol 71:420–430 Kostoglou-Athanassiou I (2013) Therapeutic applications of melatonin. Adv Endocrinol Metab 4(1):13–24 Acuña Castroviejo D, Escames G, Carazo A, León J, Khaldy H, Reiter RJ (2002) Melatonin, mitochondrial homeostasis and mitochondrial-related diseases. Curr Top Med Chem 2(2):133–151 Witt-Enderby PA, Radio NM, Doctor JS, Davis VL (2006) Therapeutic treatments potentially mediated by melatonin receptors: potential clinical uses in the prevention of osteoporosis, cancer and as an adjuvant therapy. J Pineal Res 41(4):297–305 Calvo-Guirado JL, Gómez-Moreno G, Barone A, Cutando A, Alcaraz-Baños M, Chiva F et al (2009) Melatonin plus porcine bone on discrete calcium deposit implant surfaces stimulates osteointegration in dental implants. J Pineal Res 47:164–172 Tan DX, Manchester LC, Reiter RJ et al (1999) Identification of highly elevated levels of melatonin in bone marrow: its origin and significance. Biochim Biophys Acta 1472:206–214 Nakade O, Koyama H, Ariji H et al (1999) Melatonin stimulates proliferation and type I collagen synthesis in human bone cells in vivo. J Pineal Res 27:106 Tresguerres IF, Clemente C, Blanco L, Khraisat A, Tamimi F, Tresguerres JA (2012 Jun) Effects of local melatonin application on implant osseointegration. Clin Implant Dent Relat Res 14(3):395–399. 10.1111/j.1708-8208.2010.00271.x van Tits LJ, Hak-Lemmers HL, Demacker PN, Stalenhoef AF, Willems PH (2000) Oxidized low-density lipoprotein induces calcium influx in polymorphonuclear leukocytes. Free Radic Biol Med 29:747–755 Maria S, Witt-Enderby PA (2014) Melatonin effects on bone: potential use for the prevention and treatment for osteopenia, osteoporosis, and periodontal disease and for use in bone-grafting procedures. J Pineal Res 56:115–125 Cerqueira A, Romero-Gavilán F, Araújo-Gomes N, García-Arnáez I, Martinez-Ramos C, Ozturan S, Azkargorta M, Elortza F, Gurruchaga M, Suay J, Goñi I (2020) A possible use of melatonin in the dental field: Protein adsorption and in vitro cell response on coated titanium. Mater Sci Eng C Mater Biol Appl 116:111262 Wang C, Wang L, Wang X, Cao Z (2022) Beneficial Effects of Melatonin on Periodontitis Management: Far More Than Oral Cavity. Int J Mol Sci 23(23):14541 Tinto M, Sartori M, Pizzi I, Verga A, Longoni S (2020) Melatonin as host modulating agent supporting nonsurgical periodontal therapy in patients affected by untreated severe periodontitis: A preliminary randomized, triple-blind, placebo-controlled study. J Periodontal Res 55:61–67 Chitsazi M, Faramarzie M, Sadighi M, Shirmohammadi A, Hashemzadeh A (2017) Effects of adjective use of melatonin and vitamin C in the treatment of chronic periodontitis: A randomized clinical trial. J Dent Res Dent Clin Dent Prospects 11:236–240 Cutando A, Montero J, Gómez-de Diego R, Ferrera M-J, Lopez-Valverde A (2015) Effect of topical application of melatonin on serum levels of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in patients with type 1 or type 2 diabetes and periodontal disease. J Clin Exp Dent 7:628–633 Anton DM, Martu MA, Maris M, Maftei GA, Sufaru IG, Tatarciuc D, Luchian I, Ioanid N, Martu S (2021) Study on the Effects of Melatonin on Glycemic Control and Periodontal Parameters in Patients with Type II Diabetes Mellitus and Periodontal Disease. Med (Kaunas) 57(2):140 El-Sharkawy H, Elmeadawy S, Elshinnawi U, Anees M (2019) Is dietary melatonin supplementation a viable adjunctive therapy for chronic periodontitis?-A randomized controlled clinical trial. J Periodontal Res 54(2):190–197 Ahmed E, Shaker OG, Yussif N, Ghalwash DM (2021) Effect of Locally Delivered Melatonin as an Adjunct to Nonsurgical Therapy on GCF Antioxidant Capacity and MMP-9 in Stage II Periodontitis Patients: A Randomized Controlled Clinical Trial. Int J Dent 2021:8840167 Montero J, López-Valverde N, Ferrera MJ, López-Valverde A (2017) Changes in crevicular cytokines after application of melatonin in patients with periodontal disease. J Clin Exp Dent 9(9):e1081–e1087 El-Gammal MY, Salem AS, Anees MM, Tawfik MA (2016) Clinical and Radiographic Evaluation of Immediate Loaded Dental Implants With Local Application of Melatonin: A Preliminary Randomized Controlled Clinical Trial. J Oral Implantol 42(2):119–125 Renn T-Y, Huang Y-K, Feng S-W, Wang H-W, Lee W-F, Lin C-T et al (2018) Prophylactic supplement with melatonin successfully suppresses the pathogenesis of periodontitis through normalizing RANKL/OPG ratio and depressing the TLR4/MyD88 signaling pathway. J Pineal Res. ; 64(3) Takechi M, Tatehara S, Satomura K, Fujisawa K, Nagayama M (2008) Effect of FGF-2 and melatonin on implant bone healing: a histomorphometric study. J Mater Sci: Mater Med 19:2949–2952 Salomó-Coll O, de Maté-Sánchez JE, Ramírez-Fernández MP, Satorres-Nieto M, Gargallo-Albiol J, Calvo-Guirado JL (2016) Osseoinductive elements for promoting osseointegration around immediate implants: A pilot study in the foxhound dog. Clin Oral Implant Res 27:e167–e175 Dundar S, Yaman F, Saybak A, Ozupek MF, Toy VE, Gul M et al (2016) Evaluation of Effects of Topical Melatonin Application on Osseointegration of Dental Implant: An Experimental Study. J Oral Implantol 42(5):386–389 Calvo-Guirado JL, Aguilar Salvatierra A, Gargallo-Albiol J, Delgado-Ruiz RA, Maté Sanchez JE, Satorres-Nieto M (2015) Zirconia with laser-modified microgrooved surface vs. titanium implants covered with melatonin stimulates bone formation. Experimental study in tibia rabbits. Clin Oral Implants Res 26(12):1421–1429 Guardia J, Gómez-Moreno G, Ferrera MJ, Cutando A (2011) Evaluation of effects of topic melatonin on implant surface at 5 and 8 weeks in Beagle dogs. Clin Implant Dent Relat Res 13:262–268 Hazzaa HH, El-Kilani NS, Elsayed SA, Abd El Massieh PM (2019) Evaluation of immediate implants augmented with autogenous bone/melatonin composite graft in the esthetic zone: a randomized controlled trial. J Prosthodont 28:637–642 De Waal YC, Eijsbouts HV, Winkel EG, van Winkelhoff AJ (2017) Microbial Characteristics of Peri-Implantitis: A Case-Control Study. J Periodontol 88(2):209–217 Canullo L, Peñarrocha-Oltra D, Covani U, Rossetti PH (2015 Jul-Aug) Microbiologic and Clinical Findings of Implants in Healthy Condition and with Peri-Implantitis. Int J Oral Maxillofac Implants 30(4):834–842 Jezdic M, Nikolic N, Krasavcevic AD, Milasin J, Aleksic Z, Carkic J et al (2023) Clinical, microbiological and osteoimmunological findings in different peri-implant conditions - A cross-sectional study. Clin Oral Implants Res 34(9):958–966 Ebadian AR, Kadkhodazadeh M, Zarnegarnia P, Dahlén G (2012) Bacterial analysis of peri-implantitis and chronic periodontitis in Iranian subjects. Acta Med Iran 50(7):486–492 Korsch M, Marten SM, Stoll D, Prechtl C, Dötsch A (2021) Microbiological findings in early and late implant loss: an observational clinical case-controlled study. BMC Oral Health 21(1):112 Sanz-Martin I, Doolittle-Hall J, Teles RP, Patel M, Belibasakis GN, Hämmerle CHF et al (2017) Exploring the microbiome of healthy and diseased peri-implant sites using Illumina sequencing. J Clin Periodontol 44(12):1274–1284 Ding Q, Tan KS (2016) The Danger Signal Extracellular ATP Is an Inducer of Fusobacterium nucleatum Biofilm Dispersal. Front Cell Infect Microbiol 6:155 Ghensi P, Manghi P, Zolfo M, Armanini F, Pasolli E, Bolzan M et al (2020) Strong oral plaque microbiome signatures for dental implant diseases identified by strain-resolution metagenomics. NPJ Biofilms Microbiomes 6(1):47 Han YW (2015) Fusobacterium nucleatum: a commensal-turned pathogen. Curr Opin Microbiol 23:141–147 Polak D, Wilensky A, Shapira L, Halabi A, Goldstein D, Weiss EI et al (2009) Mouse model of experimental periodontitis induced by Porphyromonas gingivalis/Fusobacterium nucleatum infection: bone loss and host response. J Clin Periodontol 36(5):406–410 He F, Wu X, Zhang Q, Li Y, Ye Y, Li P, Chen S, Peng Y, Hardeland R, Xia Y (2021) Bacteriostatic Potential of Melatonin: Therapeutic Standing and Mechanistic Insights. Front Immunol 12:683879 Wang HX, Liu F, Ng TB (2001) Examination of pineal indoles and 6-methoxy-2-benzoxazolinone for antioxidant and antimicrobial effects. Comp Biochem Physiol C Toxicol Pharmacol 130(3):379–388 Tekbas OF, Ogur R, Korkmaz A, Kilic A, Reiter RJ (2008) Melatonin as an antibiotic: new insights into the actions of this ubiquitous molecule. J Pineal Res 44(2):222–226 Zhou W, Zhang X, Zhu CL, He ZY, Liang JP, Song ZC (2016) Melatonin Receptor Agonists as the Perioceutics Agents for Periodontal Disease through Modulation of Porphyromonas gingivalis Virulence and Inflammatory Response. PLoS ONE 11(11):e0166442 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-7095643","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":495499500,"identity":"4c438d83-d27e-41b6-8afe-8506fd969f05","order_by":0,"name":"Carlos Manuel 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University of Madrid","correspondingAuthor":false,"prefix":"","firstName":"José","middleName":"María","lastName":"Martínez-González","suffix":""},{"id":495499509,"identity":"fa79022b-c783-4811-b690-312a34657941","order_by":6,"name":"Juan López-Quiles","email":"","orcid":"","institution":"Complutense University of Madrid","correspondingAuthor":false,"prefix":"","firstName":"Juan","middleName":"","lastName":"López-Quiles","suffix":""}],"badges":[],"createdAt":"2025-07-10 18:53:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7095643/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7095643/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88502649,"identity":"e1b3cd96-3992-40ae-ad13-26133a0895f2","added_by":"auto","created_at":"2025-08-07 06:59:31","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":443670,"visible":true,"origin":"","legend":"\u003cp\u003ePeri-implant treatment sequence.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7095643/v1/241e6ccf33e0b51692baa40b.png"},{"id":88504391,"identity":"be2f81ba-934d-4613-83fa-1f3104063f46","added_by":"auto","created_at":"2025-08-07 07:07:31","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":205496,"visible":true,"origin":"","legend":"\u003cp\u003eRadiologic analysis of marginal bone loss changes initially, at 21 days and at 60 days.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7095643/v1/527f2aff5e9e8cc8f1cc8e99.png"},{"id":88504393,"identity":"22f03b51-845e-4861-a973-7b926244271d","added_by":"auto","created_at":"2025-08-07 07:07:32","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":84079,"visible":true,"origin":"","legend":"\u003cp\u003eFlow diagram of the patient’s recruitment\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7095643/v1/8ba68ddb75037a55af326495.png"},{"id":91195161,"identity":"e089d874-912c-4d95-ae67-d0c3174ca921","added_by":"auto","created_at":"2025-09-12 14:53:53","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2062786,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7095643/v1/63f71781-b232-4eb8-809b-92acbab03b9a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eApplication of local melatonin for controlling peri-implantitis: a randomized clinical trial\u003c/p\u003e","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003ePeri-implant diseases are a host response to the formation of a biofilm on the implant surface. They are initiated by inflammatory reactions with an increase in interleukins (IL-1, IL-6, IL-8 and IL-17) produced by bacterial species in the soft tissue surrounding the implant and can subsequently lead to loss of bone support [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. According to the Sixth European Consensus of Periodontology (2008) its incidence is between 28–56%. Although the etiology of these diseases is not clear, the increased presence of gram-negative microorganisms and spirochetes has been determined [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. It is known that the increase in IL-6 in the injured area triggers the production of the first symptoms of inflammation and stimulates bone resorption in the initial stages of osteoclastogenesis [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Treatment protocols for peri-implant diseases are not established and have limitations when there is peri-implant bone loss. Due to the importance of periodontal therapy, several authors propose the investigation of anti-inflammatory and preventive agents such as melatonin, using this molecule as complementary therapeutic strategies in models of periodontal disease [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eMelatonin (N-acetyl-5-methoxytryptamine) is a highly lipophilic pleiotropic hormone synthesized mainly in the pineal gland. Its therapeutic applications derive from its two main properties, its high antioxidant power and its great lipid solubility [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Due to these properties, it has been used successfully after oral surgery, with stimulating and protective effects on the intracellular enzymes involved in the healing process, inhibiting the production of prostaglandins, TNF-α, and interleukins (IL-1β, IL-6, IL-8 and IL-10) [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Several studies have confirmed the anti-inflammatory activity produced by melatonin in situations of acute inflammation and exacerbated immune response [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e–\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. On the contrary, other studies have shown that exogenous administration of melatonin above the body's basal levels stimulates the immune system by increasing the proliferation of T lymphocytes, NK cells and granulocytes, and the antibody response [\u003cspan additionalcitationids=\"CR15 CR16\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e–\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. T cell activation increases the release of inflammatory cytokines such as interferon-ɣ, TNF-α, IL-1, IL-1β, IL-2, IL-6, and IL-12.\u003c/p\u003e\u003cp\u003eThe stimulation of the immune and inflammatory system depends on the concentration of melatonin, which is responsible for the inflammatory response and the body's defense against bacterial and viral infections [\u003cspan additionalcitationids=\"CR19 CR20\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e–\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eMelatonin has been used in bone formation and the stimulation of bone metabolism [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. In osseointegrated implants, earlier osteoblast differentiation, an increase in osteoblast proliferation and an acceleration in the synthesis and mineralization of the osteoid matrix have been observed after 2 weeks and 4 weeks of implant placement, as well as a significant increase in the width and length of cortical bone [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. In histological analysis, the local application of melatonin has been shown to increase trabecular formation by directly stimulating osteoblasts from the endosteum [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Furthermore, it has been described a slight increase in radiological bone density at 15 days without relevant inflammatory phenomena at a macroscopic level. However, no differences with untreated bone in imaging or microscopic tests at 60 days were found, behaving as a biomimetic agent, with anti-inflammatory and osteogenic properties [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe effectiveness of melatonin in restricting the survival and growth of bacteria is explained by its diffusion properties through the bacterial cell wall and its ability to reduce the levels of lipids present in cell membranes. Gram-negative bacteria have an internal and external cell membrane composed of glycopeptide proteins, lipopolysaccharides and large amounts of lipids, which explains that the antimicrobial activity of melatonin is greater in these bacteria. Furthermore, bacteria are highly dependent on free metals for their growth, particularly iron. Once in the cytoplasm, melatonin binds iron (III), copper and zinc, thus reducing their cytoplasmic availability due to its high metal binding capacity. This mechanism is of special relevance in an infected environment in an environment with metals, such as peri-implant infections.\u003c/p\u003e\u003cp\u003ePeri-implant bone loss is established and progresses due to oxidative stress processes produced by oral biofilm, which activate osteoclasts directly, and by the indirect destruction of membrane lipids and collagen fibers produced by activated polymorphonuclear cells [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Proinflammatory cytokines, such as TNFα, a granulocyte and macrophage-stimulating factor (IL-1, IL-6, and IL-8), and lipopolysaccharide, among others, also stimulate polymorphonuclear cells to produce higher levels of oxidative stress [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe main objective of the present research is to determine the effectiveness of melatonin in the treatment of peri-implant diseases. The secondary objectives are to determine the anti-inflammatory, osteogenic and bactericidal properties of melatonin.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003e This Randomized Clinical Trial was carried out following the recommendations of the Consolidated Standards Of Reporting Trials Declaration (CONSORT 2010), the requirements established in the Declaration of Helsinki (World Medical Assembly), and in accordance with the Data Protection Law (the Organic Law 3/2018, of December 5, on Protection of Personal Data and guarantee of digital rights). The protocol was approved by the Clinical Research Ethics Committee (CEIC) of the San Carlos Clinical Hospital of Madrid, minute 7.2/19; C.P. MEL19 - C.I. 19/313-E.\u003c/p\u003e\u003cp\u003eIn Spain, the Spanish Agency for Medicines and Health Products (AEMPS), dependent on the Ministry of Health, establishes that the use of melatonin in doses greater than 1.9 mg was only possible under medical prescription for the treatment of sleep disorders and hyperactivity disorders, or autism spectrum (Royal Legislative Decree 1/2015), which is why it is only marketed in Spain in doses less than 2 mg.\u003c/p\u003e\u003cp\u003e\u003cb\u003eRecruitment\u003c/b\u003e\u003c/p\u003e\u003cp\u003eVolunteer participants diagnosed with peri-implant disease were recruited according to the criteria of the Classification of Periodontal and Peri-implant Diseases and Conditions of the 2017 World Workshop, with an indication for peri-implant surgical treatment, with one or more fully erupted teeth. Patients of both sexes were included, aged between 40 and 85 years, in healthy condition (Category I and II of the American Society of Anesthesiologists [ASA]), with no history or metabolic or systemic diseases that affected the bone or the healing process. as is the case of diabetes, without autoimmune diseases, coagulation or healing disorders and who, meeting the inclusion criteria, agreed to sign the informed consent.\u003c/p\u003e\u003cp\u003eExclusion criteria were established as tobacco consumption \u0026gt; 25 cigarettes a day, the use of hormonal, anti-inflammatory, corticosteroids, immunosuppressants, analgesics, antidiabetic or antiresorptive medications on a regular or recent basis, pregnant or breastfeeding women, and those who refused to participate in the study or did not allow follow-up and sample collection.\u003c/p\u003e\u003cp\u003e\u003cb\u003eStudy design\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe implant with the most severe involvement was selected, although the treatment was performed on all implants, to prevent patients with more affected implants from having greater statistical relevance.\u003c/p\u003e\u003cp\u003ePrior to treatment (T0), the peri-implant clinical and radiological study was carried out using periapical radiography with a parallelize and samples of crevicular fluid from the implant were obtained in duplicate.\u003c/p\u003e\u003cp\u003eThe peri-implant surgical treatment was performed under local infiltrative anesthesia with 4% articaine with 1:100,000 adrenaline. Debridement was performed using ultrasound with irrigation, complemented using curettes. Treatment with melatonin or placebo was applied through computer block randomization. To achieve blinding, a different code was assigned to the group applying 1.9 mg of melatonin (A) and to the control group (B) applying placebo (dextrinomaltose 2 mg) powder and the samples and records were coded. It was sutured with 4/0 monofilament in a pre-assembled 3/8 semicircular needle (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn all patients, 1000 mg of Paracetamol was prescribed every 8 hours in case of pain, and it was indicated not to rinse or use any topical antiseptic.\u003c/p\u003e\u003cp\u003eAt 7 days (T1), the healing process was reviewed, sutures were removed, and crevicular fluid samples were taken. At 21 days (T2), a new complete peri-implant registration, new crevicular fluid samples and a radiological study were performed. At 60 days (T3), a new complete peri-implant registration, crevicular fluid samples and radiological study were performed.\u003c/p\u003e\u003cp\u003eTo detect the appearance of complications, a record of adverse events was established for a period of two months after treatment.\u003c/p\u003e\u003cp\u003e\u003cb\u003eVariables\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eProbing depth\u003c/span\u003e\u003c/p\u003e\u003cp\u003eThe distance from the gingival margin to the bottom of the periodontal pocket was considered. The measurement was carried out in the four locations surrounding the implant, mesial, distal, lingual and vestibular. Additionally, the average of the four locations was presented.\u003c/p\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003ePlaque Index (Löe y Silness)\u003c/span\u003e\u003c/p\u003e\u003cp\u003eThe presence of visible bacterial plaque was considered adapted to rehabilitation using implants (Grade 0: No plaque; Grade 1: No plaque with the naked eye. There is plaque when the exploration is performed with a probe in the peri-implant area; Grade 2: There is visible bacterial plaque; Grade 3: There is visible bacterial plaque surrounding the implant, including interdental spaces. There may be stones.\u003c/p\u003e\u003cp\u003eAdequate plaque control is considered to exist when the index results in a value ≤ 1.\u003c/p\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eBleeding Index (Löe y Silness)\u003c/span\u003e\u003c/p\u003e\u003cp\u003eIt was considered during the 30 seconds after probing adapted to the implant model (Grade 0: Absence of bleeding; Grade 1: A spot of blood does not appear until a few seconds after probing; Grade 2: Bleeding immediately after of probing; Grade 3: Bleeding at the slightest contact with the mucosa, extension of bleeding along the sulcus).\u003c/p\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eMarginal bone loss\u003c/span\u003e\u003c/p\u003e\u003cp\u003eThe evaluation of the peri-implant-crestal bone level was performed using the ImageJ® program (NIH, Bethesda, MD, USA). From the measurement in pixels of the known length of the implant, the vertical measurement of the bone level was determined from the implant platform and perpendicular to it, to the area of ​​turbinate bone in contact with the surface of the implant both mesial and distal. It was considered as a single measurement of the mesial and distal mean of each implant considering the clinical significance (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eIL-1β and IL-6 concentration\u003c/span\u003e\u003c/p\u003e\u003cp\u003eCrevicular fluid samples obtained using Perio-paper strips were analyzed with the enzyme-linked immunosorbent assay (ELISA) technique. The samples were stored in sterile 13x75mm x 2 mL BD Vacutainer® tubes and were processed using the ELH-IL1B-1 Human IL-1 beta ELISA Kits 1 x 96-Wel BIONOVA CIENTIFICA S.L and HEA079HU-48T High Sensitive ELISA Kit for Interleukin 6 (IL-6) 48T BIONOVA CIENTIFICA SL for analysis of interleukin-1β and 6 at 60–90 minutes after obtaining it. The determinations were read using the ELISA reader (Ivymen System 2100-C). The standard curve of the kits was made in duplicate for IL-1β and IL-6 both in the test and in the total analysis of the samples.\u003c/p\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eMicrobiological count\u003c/span\u003e\u003c/p\u003e\u003cp\u003eA Colon Forming Unit (CFU) count was performed on the crevicular fluid samples obtained using sterile paper points. They were transferred into a vial of reduced transport liquid with 1.0 mL of RTF transport medium to preserve the anaerobiosis of the samples for 24 hours and quantify the sample volume. The samples were immediately cultured on blood agar medium and the peri-implantopathogenic, periodontopathogenic and candida species were identified.\u003c/p\u003e\u003cp\u003e\u003cb\u003eSample size calculation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe calculation of the sample size was carried out taking as reference previous similar studies [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. 30 patients (15/15) were considered to detect differences with a large effect size (d = 1) and with a statistical power of 80%. Considering a possible drop out of patients, a minimum recruitment of 33 patients was estimated.\u003c/p\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eA descriptive analysis of the most relevant statistics was carried out for all the variables collected in the research: absolute and relative frequencies (for the categorical ones) and mean, standard deviation, range, median and 25th and 75th percentiles (for the continuous ones).\u003c/p\u003e\u003cp\u003eThe Shapiro-Wilk test was applied to evaluate the adjustment to a normal distribution of the variables in both groups. To carry out the inferential analysis, the non-parametric Brunner-Langer Model for longitudinal data was used. To study the evolution of the different variables (clinical, inflammatory, microbiological) throughout all measurements of the period depended on the type of treatment.\u003c/p\u003e\u003cp\u003eA level of statistical significance p ≤ 0.05 was established.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003e41 participants were recruited consecutively, of which 11 participants were excluded. A final sample of 30 patients was analyzed, 10 men (33.3%) and 20 women (66.7%), with a mean age of 71.9\u0026thinsp;\u0026plusmn;\u0026thinsp;7.3 years (48\u0026ndash;85 years) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe results of the homogeneity tests showed that the groups were homogeneous, and the variables were not potential confounders (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\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\u003eTests of homogeneity of treatment groups according to independent variables \u003cb\u003eChi2 Test and Mann-Whitney test\u003c/b\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSEX\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.439 (Chi\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAGE\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.838 (MW)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSMOKERS\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.682 (Fis)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDISEASES\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.464 (Chi\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDYSLIPEMIA\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.000 (Fis)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eHIGH BLOOD PRESSURE\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.705 (Chi\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eANEMIA\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.000 (Fis)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDIABETES\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.483 (Fis)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eHYPOTIROIDISM\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.483 (Fis)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTOOTH TYPE\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.587 (Chi\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eARCH\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.705 (Chi\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eBRAND\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.502 (Chi\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRESTORATION TYPE\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.140 (Chi\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003csup\u003e*p\u0026lt;0.05; **p\u0026lt;0.01; ***p\u0026lt;0.001\u003c/sup\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe evolution of the vestibular, palatal, mesial, distal and average probing depth between both groups (interaction effect) determined that both treatments produced a significant decrease throughout the follow-up (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). There were no statistically significant differences in probing depth levels in any location according to the type of treatment.\u003c/p\u003e\u003cp\u003eNo differences were observed in the average probing depth level depending on the treatment applied (A or B) (p\u0026thinsp;=\u0026thinsp;0.170). After the analysis, a reduction in probing depth was observed in group A of 1.80 mm and in group B of 1.38 mm at 60 days (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). This is a lower effect size (d\u0026thinsp;=\u0026thinsp;0.5) than that proposed in the statistical power calculation prior to the study and explains why we did not find statistically significant differences (p\u0026thinsp;=\u0026thinsp;0.307).\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\u003eDescriptive values ​​of the mean peri-implant probing depth throughout the follow-up according to groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\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\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u003cp\u003eGROUP\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMelatonin\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePlacebo\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003ePSmeanT0\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5,46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5,78\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e5,13\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,91\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3,25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3,25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7,75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e7,75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e6,25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4,25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5,50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5,50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e5,50\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e7,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e5,75\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003ePSmeanT2\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4,24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4,53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3,95\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,77\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,65\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3,50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4,75\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4,25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4,25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4,25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4,75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4,50\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003ePSmeanT3\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3,87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3,98\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3,75\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,72\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,71\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2,50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2,50\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5,50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5,50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4,75\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3,25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3,25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4,25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4,25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4,50\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eBoth treatments produced a significant decrease in the plaque index throughout the follow-up time (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The level of plaque index is significantly higher in group A than in B (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). No significant interaction is observed (p\u0026thinsp;=\u0026thinsp;0.568). That is, the evolution of the plaque index is similar in both groups over time. Therefore, the progression of the plaque index in group A can be extrapolated to any time and does not present differences compared to group B (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\u003eDescriptive blues of the Plaque Index throughout the follow-up according to groups.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\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\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u003cp\u003eGROUP\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMelatonin\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePlacebo\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003eIP T0\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2,07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,73\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,46\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003eIP T2\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,26\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003eIP T3\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,47\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,64\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eBoth treatments produced a significant decrease in the Bleeding Index throughout the follow-up (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The Bleeding Index level is globally similar between groups (p\u0026thinsp;=\u0026thinsp;0.298). Bleeding control is comparable between both treatments, with no statistically significant differences between both (p\u0026thinsp;=\u0026thinsp;0.910).\u003c/p\u003e\u003cp\u003eBoth melatonin treatment and placebo produce a significant decrease in marginal bone loss throughout follow-up (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The level of marginal bone loss is somewhat higher, with more negative values, in group A compared to group B (p\u0026thinsp;=\u0026thinsp;0.051). However, the evolution of marginal bone loss was statistically similar between both groups (p\u0026thinsp;=\u0026thinsp;0.431) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\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\u003eDescriptive values ​​of the mean marginal bone loss throughout the follow-up according to groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\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\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u003cp\u003eGROUP\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMelatonin\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePlacebo\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003eMBL T0\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-4,43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-4,87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,93\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-6,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003eMBL T2\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-4,20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-4,47\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-3,93\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1,06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e,96\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-6,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-6,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cb\u003eMBL T3\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-3,60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-3,20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eStandard deviation\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1,04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e,93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1,01\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMinimum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMaximum\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-2,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-2,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e25th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-5,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMedian\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-4,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e75th percentile\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-3,00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-2,00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe concentration of IL-1β presents significant variations throughout the follow-up (p\u0026thinsp;=\u0026thinsp;0.010). There were no statistically significant differences in IL-1β levels according to the type of treatment (p\u0026thinsp;=\u0026thinsp;0.804). This behavior can be extrapolated to any of the treatments (p\u0026thinsp;=\u0026thinsp;0.555). It should be noted that at time T3 (60 days) the medians are practically the same in both groups (8.3 pg/mL) and so are the global variations T3-T0 (0 pg/mL). At 7 days, both groups presented uniform values, with little variability except for atypical cases. At 21 days the range of possible values ​​amplifies again and remains this way until 60 days.\u003c/p\u003e\u003cp\u003eThe statistical results of the model concluded that the treatments produce a significant increase in IL-6 throughout the follow-up (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). There is no effect dependent on the study group. The increase in IL-6 presents a similar pattern in both groups with no statistically significant differences between them (p\u0026thinsp;=\u0026thinsp;0.515). It should be noted that at time T3 (60 days) the medians are 0.19 and 0.16 pg/mL in treatment A and B respectively. The overall T3-T0 change was, respectively, 0.15 and 0.13 pg/mL.\u003c/p\u003e\u003cp\u003eThe initial total anaerobic bacteria count in the melatonin group was 2,156,933.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2,000,755.1 CFU/mL and in the placebo group was 3,545,333.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2,330,973.5 CFU/mL. At 60 days, 1,841,446.7\u0026thinsp;\u0026plusmn;\u0026thinsp;2,161,934.9 CFU/mL and 2,137,800.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2,482,920.8 CFU/mL were found, respectively.\u003c/p\u003e\u003cp\u003eRegarding the total number of anaerobic species, no statistically significant differences were observed in terms of their count throughout the follow-up (p\u0026thinsp;=\u0026thinsp;0.328). There were also no statistically significant differences in the treatment group. Stability was applicable to both groups and without statistically significant differences between the groups (p\u0026thinsp;=\u0026thinsp;0.959).\u003c/p\u003e\u003cp\u003eChanges in the amount of Porphyromona gingivalis depended specifically on the type of treatment (p\u0026thinsp;=\u0026thinsp;0.046). For each treatment there is a notable oscillation in the charge of this bacteria and this pattern of charge oscillation is antagonistic.\u003c/p\u003e\u003cp\u003eThe amount of Prevotella intermedia detected changes significantly in the study period (p\u0026thinsp;=\u0026thinsp;0.013). This change is statistically similar in both groups, with no statistically significant differences between treatment and placebo (p\u0026thinsp;=\u0026thinsp;0.599).\u003c/p\u003e\u003cp\u003eThe amount of Fusobacterium nucleatum remains stable over time (p\u0026thinsp;=\u0026thinsp;0.154). The bacterial load of Fusobacterium nucleatum in the placebo group is higher than in melatonin group (p\u0026thinsp;=\u0026thinsp;0.039). This statement includes time T0, so it cannot be an effect attributable to the treatment. A similar longitudinal pattern of bacterial load is found in both treatment groups (p\u0026thinsp;=\u0026thinsp;0.125).\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThe conventional treatment of peri-implant pathologies has demonstrated limited effectiveness, which is why the need for bioactive molecules has been proposed. The described biological properties of melatonin have placed this molecule as an alternative that deserves consideration in implant dentistry [\u003cspan additionalcitationids=\"CR30\" citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. There are no clinical trials in humans in the literature that treat peri-implant disease states with bone loss through the local application of melatonin. Therefore, the different doses, routes of administration and type of pathology make comparison with the present clinical trial difficult, in addition to the use of other topical antiseptics in most previous studies.\u003c/p\u003e\u003cp\u003eIn the present study, the reduction in the average probing depth in the melatonin group (1.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88 mm) does not present statistical differences compared to the control group (1.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47 mm), although it can be verified that there is an improvement in probing depth in all locations in both groups. This improvement is most noticeable at 21 days and remains stable at 60 days.\u003c/p\u003e\u003cp\u003eThe initial plaque index values ​​in both groups correspond to states of poor plaque control by the patient. Higher values ​​were recorded in the melatonin group throughout all phases of the study, which could be related to a worse outcome of the peri-implant treatment. However, the results are not worse compared to the control.\u003c/p\u003e\u003cp\u003eThe initial mean bleeding index for both groups correspond to peri-implant disease states. At the end of the follow-up time, improvement was found, with a reduction in the bleeding index of 1.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49 for the melatonin group and 1.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51 for the control group.\u003c/p\u003e\u003cp\u003eThere are some studies that compare periodontal clinical parameters such as probing depth, plaque index and bleeding index in groups of patients with periodontal disease to whom melatonin is applied [\u003cspan additionalcitationids=\"CR36\" citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Authors such as Tinto et al. [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e], Chitsazi et al. [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e], Cutando et al. [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e], and Anton et al. [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e] found favorable differences in terms of probing depth in periodontal disease by supplying 1 mg of melatonin daily orally for 4 weeks, 2 mg daily orally for 4 weeks, 1% topically for 20 days and 3 mg orally daily for 2 months. On the other hand, El-Sharkawy et al. [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e], using 10 mg daily orally for 2 months in the treatment of periodontal disease, found a decrease in plaque index values ​​from 2.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45 to 0.84. \u0026plusmn; 0.26 at 3 months and the bleeding index from 2.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36 to 0.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19, although without statistically significant differences. The only periodontal parameter that registers significant differences compared to the control is the probing depth, evolving from 4.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8 mm to 2.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0 mm. The study by Ahmed et al. [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e] evaluates the effect of 5% melatonin gel administered locally as a complement to non-surgical periodontal therapy in patients with stage II periodontitis in terms of probing depth, clinical insertion level, plaque index, and bleeding index at 3 months. Their results agree with the study by Montero et al. [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e], which reported that topical application of melatonin has positive effects on periodontal health and resulted in a significant improvement in clinical parameters such as gingival index and probing depth [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eUnlike the results described by previous studies, in the present investigation no statistically significant differences were found regarding treatment with melatonin. This could be due to the dose used and in a unique way that in other investigations was carried out continuously.\u003c/p\u003e\u003cp\u003eThe initial mean marginal bone loss corresponds to advanced peri-implant disease states, although a greater loss is seen in the melatonin group (-4.87\u0026thinsp;\u0026plusmn;\u0026thinsp;1.25 mm) compared to the placebo (-4.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93 mm). At the end of the follow-up, a greater improvement was found in the melatonin group (0.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.74 mm) compared to the control (0.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68 mm), which could be promising despite exhibiting a limited effect due to the advanced peri-implant disease. Most studies describe beneficial effects in controlling marginal bone loss and peri-implant bone density in topical use [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. However, these studies include experimental studies [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan additionalcitationids=\"CR43 CR44\" citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e], coating the implant [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e] or injected around the implants. implants at the time of placement [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e], so the results are not comparable.\u003c/p\u003e\u003cp\u003eIts application in peri-implant bone regeneration with autologous bone shows favorable differences in terms of marginal bone loss, although they are not found in probing depth according to Hazzaa et al. [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe evolution of IL-1β concentration shows a decrease after 7 days in both groups, although initially the value in the melatonin group was higher (9.84\u0026thinsp;\u0026plusmn;\u0026thinsp;5.47 pg/mL) and similar values ​​are reached in both groups. (6.80\u0026thinsp;\u0026plusmn;\u0026thinsp;3.83 pg/mL vs 6.79\u0026thinsp;\u0026plusmn;\u0026thinsp;4.20 pg/mL), but without differences between both groups. At 21 and 60 days it is observed that the concentration increases in both groups but in the melatonin group it maintains greater stability (8.37\u0026thinsp;\u0026plusmn;\u0026thinsp;6.08 pg/mL and 8.62\u0026thinsp;\u0026plusmn;\u0026thinsp;5.09 pg/mL) than in the group. placebo (7.27\u0026thinsp;\u0026plusmn;\u0026thinsp;5.52 pg/mL and 9.07\u0026thinsp;\u0026plusmn;\u0026thinsp;5.57 pg/mL). Regarding the concentration of IL-6, it experienced an increase after 7 days in both groups. At 21 days it is observed that the concentration decreases and at 60 days it increases again in a similar way in both groups. Authors such as Hazzaa et al. [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e] found significant reductions in proinflammatory interleukins, such as TNF α, IL-6 and CRP after two months by providing 6 mg/day orally of melatonin as an adjuvant to periodontal therapy.\u003c/p\u003e\u003cp\u003eThe periodontal pathogens Porhyromona gingivalis, Prevotella intermedia, Tannerella forsythia and Fusobacterium nucleatum are the most frequently associated with peri-implantitis [\u003cspan additionalcitationids=\"CR48 CR49 CR50 CR51\" citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. Several studies affirm that Fusobacterium species are found in the initial stages and their increase is related to a greater severity of peri-implant disease [\u003cspan additionalcitationids=\"CR54\" citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]. P. gingivalis species and other strains are among the dominant bacterial species in advanced peri-implant diseases and failed implants. Coinfection with P. gingivalis and Fusobacterium has been shown to synergistically increase bone loss and exacerbate host inflammatory responses, being related with the progression of peri-implant clinical parameters [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e, \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e]. Previous scientific evidence describes that melatonin exerts antibacterial activities on common gram-negative and positive bacteria. The direct actions of melatonin can occur only at very high concentrations, which is a limitation in terms of clinical applicability. However, other indirect mechanisms include the activation of host defense mechanisms or, in sepsis, the attenuation of bacteria-induced inflammation [\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e]. The binding of melatonin to free metals in the peri-implant environment may have favorable bacteriostatic properties, since bacterial growth is dependent on these metals [\u003cspan additionalcitationids=\"CR58\" citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe properties of melatonin against bacteria such as Porphyromonas gingivalis have been demonstrated in in vitro models [\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eRegarding the anaerobic bacterial species found in the present study, it seems that the application of melatonin does not present favorable differences compared to placebo in the total number of anaerobes. On Porphyromonas gingivalis counts, melatonin produces an antagonistic effect to that which occurs with placebo. This behavior should be studied in future research, since it does not correspond to the results of any previous study. A favorable effect of melatonin is found in terms of reducing Prevotella intermedia in the long term.\u003c/p\u003e\u003cp\u003eThe effects on Fusobacterium nucleatum do not present significant differences, although its behavior does not obey any pattern.\u003c/p\u003e\u003cp\u003eDespite the limitations regarding the dose of melatonin applied according to the legislation in force at the time, it could be deduced from the results that the concentration is insufficient to produce significant direct effects. It should be considered that to observe direct effects in environments where there are bacteria that coexist with salivary melatonin, the administered dose should be much higher. Other limitations that must be considered are the patient's oral hygiene habits and local conditions such as the three-dimensional position of the implants, the thickness and characteristics of the peri-implant mucosa.\u003c/p\u003e\u003cp\u003eDespite not finding statistically significant differences in the study variables based on applying melatonin versus a placebo, favorable changes are observed in the parameters evaluated over time. Its application could be favorable in improving the plaque index, bleeding index, reducing probing depth and peri-implant marginal bone loss, in addition to controlling certain bacterial species in the short term, such as Prevotella intermedia and Fusobacterium nucleatum, and in the long term like Porphyromona gingivalis.\u003c/p\u003e\u003cp\u003eIn conclusion, no significant differences were observed when using a placebo in terms of probing depth, Plaque Index, Bleeding Index, marginal bone loss, IL-1β and IL-6 levels, overall. of anaerobic species, Prevotella intermedia and Fusobacterium nucleatum throughout the follow-up. Differences were found in the count of Porphyromona gingivalis throughout the follow-up. No complications were recorded in any group throughout the study follow-up period.\u003c/p\u003e\u003cp\u003eDespite not finding statistically significant differences in the study variables based on applying melatonin versus a placebo, favorable changes are observed in the parameters evaluated over time. For this reason, it would be advisable to carry out more research by increasing the applied dose of melatonin and the sample, with a similar methodology, to be able to establish the differences with the application of a placebo.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eAEMPS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eSpanish Agency for Medicines and Health Products\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eASA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eAmerican Society of Anesthesiologists\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eBOP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eBleeding Rate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCAL\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eClinical Attachment Loss\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCEIC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eClinical Research Ethics Committee\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCmax\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMaximum concentration\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCONSORT\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eConsolidated Standards of Reporting Trials\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eSD\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eStandard Deviation\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eELISA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eEnzyme-linked immunosorbent assay\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eInterleukin\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eTNF\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eTumor Necrosis Factor\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eETHICS APPROVAL AND CONSENT TO PARTICIPATE\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was conducted in accordance with the requirements established in the Declaration of Helsinki (World Medical Assembly) and with the Data Protection Law (the Organic Law 3/2018, of December 5, on Protection of Personal Data and guarantee of digital rights).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe protocol was approved by the Clinical Research Ethics Committee (CEIC) of the San Carlos Clinical Hospital of Madrid, dated 07/02/2019; C.P. MEL19 - C.I. 19/313-E.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe informed consent for participants was obtained previously for all the participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCONSENT FOR PUBLICATION\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAVAILABILITY OF DATA AND MATERIALS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData and materials are available at the\u0026nbsp;Clinical Research Ethics Committee of the San Carlos Clinical Hospital of Madrid.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCOMPETING INTEREST\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFUNDING\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere was no funding. The authors did not receive support from any organization for the submitted work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAUTHORS CONTRIBUTIONS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis Randomized Clinical Trial was carried out following the recommendations of the Consolidated Standards Of Reporting Trials Declaration (CONSORT 2010), the requirements established in the Declaration of Helsinki (World Medical Assembly), and in accordance with the Data Protection Law (the Organic Law 3/2018, of December 5, on Protection of Personal Data and guarantee of digital rights).\u0026nbsp;The protocol was approved by the Clinical Research Ethics Committee (CEIC) of the San Carlos Clinical Hospital of Madrid, minute 7.2/19; C.P. MEL19 - C.I. 19/313-E.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eACKNOWLEDGEMENTS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eGazivoda D, Dzopalic T, Bozic B et al (2009) Production of proinflammatory and immunoregulatory cytokiness by inflammatory cells from periapical lesions in culture. J Oral Pathol Med 38:605\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHurst SM, Wilkinson TS, McLoughlin RM, Jones S, Horiuchi S, Yamamoto N et al (2001) IL-6 and its soluble receptor orchestrate a temporal switch in the pattern of leukocyte recruitment seen during acute inflammation.Immunity. 14:705\u0026ndash;714\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKarring ES, Stavropoulos A, Elleegaard B, Karring T (2005) Treatment of peri-implantitis by the Vector \u0026reg; system. A pilot study. Clin Oral Implants Res 16(3):288\u0026ndash;293\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTan DX, Reiter RJ, Manchester LC et al (2002) Chemical and physical properties and potential mechanisms: melatonin as a broad-spectrum antioxidant and free radical scavenger. Curr Top Med Chem 2:181\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCutando A, Aneiros-Fern\u0026aacute;ndez J, L\u0026oacute;pez-Valverde A et al (2011) A new perspective in oral health: potential importance and actions of melatonin receptors MT1, MT2, MT3, and RZR/ROR in the oral cavity. Arch Oral Biol 56:944\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePandi-Perumal SR, Srinivasan V, Maestroni GJM, Cardinali DP, Poeggeler B, Hardeland R (2006) Melatonin. Nature\u0026acute;s most versatile biological signal? FEBS J 273:2813\u0026ndash;2838\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCarrillo-Vico A, Calvo JR, Abreu P, Lardone PJ, Garcia- Maurino S, Reiter RJ, Guerrero JM (2004) Evidence of melatonin synthesis by human lymphocytes and its physiological significance: possible role as intracrine, autocrine, and\u0026frasl;or paracrine substance. FASEB J 18:537\u0026ndash;539\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRessmeyer AR, Mayo JC, Zelosko V, Sainz RM, Tan DX, Poeggeler B, Antolin I, Zsizsik BK, Reiter RJ, Hardeland R (2003) Antioxidant properties of the melatonin metabolite N1-acetyl-5-methoxykynuramine (AMK): scavenging of free radicals and prevention of protein destruction. Redox Rep 8:205\u0026ndash;213\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eReiter RJ, Tan DX, Manchester LC, Qi W (2001) Biochemical reactivity of melatonin with reactive oxygen and nitrogen species: a review of the evidence. Cell Biochem Biophys 34:237\u0026ndash;256\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKonturek SJ, Zayachkivska O, Havryluk XO, Brzozowski T, Sliwowski Z, Pawlik M et al (2007) Protective influence of melatonin against acute esophageal lesions involves prostaglandins, nitric oxide and sensory nerves. J Physiol Pharmacol 58(2):361\u0026ndash;377\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRadogna F, Diederich M, Ghibelli L (2010) Melatonin: a pleiotropic molecule regulating inflammation. Biochem Pharmacol 80:1844\u0026ndash;1852\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCutando A, Arana C, Gomez G, Escames G, Lopez A, Ferrera MJ et al (2007) Local application of melatonin into alveolar sockets of beagle dogs reduces tooth removal-induced oxidative stress. J Periodontol 78:576\u0026ndash;583\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCarrillo-Vico A, Lardone PJ, \u0026Aacute;lvarez-S\u0026aacute;nchez N (2013) Rodr\u0026iacute;guez-Rodr\u0026iacute;guez A and Guerrero JM. Melatonin: buffering the immune system. Int J Mol Sci 14:8638\u0026ndash;8683\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXia MZ, Liang YL, Wang H, Chen X, Huang YY, Zhang ZH et al (2012) Melatonin modulates TLR4-mediated inflammatory genes through MyD88- and TRIF-dependent signaling pathways in lipopolysaccharide-stimulated RAW264.7 cells. J Pineal Res 53(4):325\u0026ndash;334\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAhmad R, Haldar C, Gupta S (2012) Melatonin membrane receptor type mt1 modulates cell-mediated immunity in the seasonally breeding tropical rodent funambulus pennanti. Neuroimmunomodulation 19:50\u0026ndash;59\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAhmad R, Haldar C (2010) Photoperiodic regulation of mt1 and mt2 melatonin receptor expression is spleen and thymus of a tropical rodent funambulus pennanti during reproductively active and inactive phases. Chronobiol Int 27:446\u0026ndash;462\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCutando A, G\u0026oacute;mez-Moreno G, Arana C, Mu\u0026ntilde;oz F, Lopez-Pe\u0026ntilde;a M, Stephenson J et al (2008) Melatonin stimulates osteointegration of dental implants. J Pineal Res 45:174\u0026ndash;179\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRadogna F, Diederich M, Ghibelli L (2010) Melatonin: a pleiotropic molecule regulating inflammation. Biochem Pharmacol 80:1844\u0026ndash;1852\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJimenez-Jorge S, Jimenez-Caliani AJ, Guerrero JM, Naranjo MC, Lardone PJ, Carrillo-Vico A, Osuna C, Molinero P (2005) Melatonin synthesis and melatonin-membrane receptor (mt1) expression during rat thymus development: Role of the pineal gland. J Pineal Res 39:77\u0026ndash;83\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAhmad R, Haldar C (2010) Melatonin and androgen receptor expression interplay modulates cell-mediated immunity in tropical rodent funambulus pennanti: An in vivo and in vitro study. Scand J Immunol 71:420\u0026ndash;430\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKostoglou-Athanassiou I (2013) Therapeutic applications of melatonin. Adv Endocrinol Metab 4(1):13\u0026ndash;24\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAcu\u0026ntilde;a Castroviejo D, Escames G, Carazo A, Le\u0026oacute;n J, Khaldy H, Reiter RJ (2002) Melatonin, mitochondrial homeostasis and mitochondrial-related diseases. Curr Top Med Chem 2(2):133\u0026ndash;151\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWitt-Enderby PA, Radio NM, Doctor JS, Davis VL (2006) Therapeutic treatments potentially mediated by melatonin receptors: potential clinical uses in the prevention of osteoporosis, cancer and as an adjuvant therapy. J Pineal Res 41(4):297\u0026ndash;305\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCalvo-Guirado JL, G\u0026oacute;mez-Moreno G, Barone A, Cutando A, Alcaraz-Ba\u0026ntilde;os M, Chiva F et al (2009) Melatonin plus porcine bone on discrete calcium deposit implant surfaces stimulates osteointegration in dental implants. J Pineal Res 47:164\u0026ndash;172\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTan DX, Manchester LC, Reiter RJ et al (1999) Identification of highly elevated levels of melatonin in bone marrow: its origin and significance. Biochim Biophys Acta 1472:206\u0026ndash;214\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNakade O, Koyama H, Ariji H et al (1999) Melatonin stimulates proliferation and type I collagen synthesis in human bone cells in vivo. J Pineal Res 27:106\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTresguerres IF, Clemente C, Blanco L, Khraisat A, Tamimi F, Tresguerres JA (2012 Jun) Effects of local melatonin application on implant osseointegration. Clin Implant Dent Relat Res 14(3):395\u0026ndash;399. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/j.1708-8208.2010.00271.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1708-8208.2010.00271.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003evan Tits LJ, Hak-Lemmers HL, Demacker PN, Stalenhoef AF, Willems PH (2000) Oxidized low-density lipoprotein induces calcium influx in polymorphonuclear leukocytes. Free Radic Biol Med 29:747\u0026ndash;755\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMaria S, Witt-Enderby PA (2014) Melatonin effects on bone: potential use for the prevention and treatment for osteopenia, osteoporosis, and periodontal disease and for use in bone-grafting procedures. J Pineal Res 56:115\u0026ndash;125\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCerqueira A, Romero-Gavil\u0026aacute;n F, Ara\u0026uacute;jo-Gomes N, Garc\u0026iacute;a-Arn\u0026aacute;ez I, Martinez-Ramos C, Ozturan S, Azkargorta M, Elortza F, Gurruchaga M, Suay J, Go\u0026ntilde;i I (2020) A possible use of melatonin in the dental field: Protein adsorption and in vitro cell response on coated titanium. Mater Sci Eng C Mater Biol Appl 116:111262\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang C, Wang L, Wang X, Cao Z (2022) Beneficial Effects of Melatonin on Periodontitis Management: Far More Than Oral Cavity. Int J Mol Sci 23(23):14541\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTinto M, Sartori M, Pizzi I, Verga A, Longoni S (2020) Melatonin as host modulating agent supporting nonsurgical periodontal therapy in patients affected by untreated severe periodontitis: A preliminary randomized, triple-blind, placebo-controlled study. J Periodontal Res 55:61\u0026ndash;67\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChitsazi M, Faramarzie M, Sadighi M, Shirmohammadi A, Hashemzadeh A (2017) Effects of adjective use of melatonin and vitamin C in the treatment of chronic periodontitis: A randomized clinical trial. J Dent Res Dent Clin Dent Prospects 11:236\u0026ndash;240\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCutando A, Montero J, G\u0026oacute;mez-de Diego R, Ferrera M-J, Lopez-Valverde A (2015) Effect of topical application of melatonin on serum levels of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in patients with type 1 or type 2 diabetes and periodontal disease. J Clin Exp Dent 7:628\u0026ndash;633\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnton DM, Martu MA, Maris M, Maftei GA, Sufaru IG, Tatarciuc D, Luchian I, Ioanid N, Martu S (2021) Study on the Effects of Melatonin on Glycemic Control and Periodontal Parameters in Patients with Type II Diabetes Mellitus and Periodontal Disease. Med (Kaunas) 57(2):140\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEl-Sharkawy H, Elmeadawy S, Elshinnawi U, Anees M (2019) Is dietary melatonin supplementation a viable adjunctive therapy for chronic periodontitis?-A randomized controlled clinical trial. J Periodontal Res 54(2):190\u0026ndash;197\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAhmed E, Shaker OG, Yussif N, Ghalwash DM (2021) Effect of Locally Delivered Melatonin as an Adjunct to Nonsurgical Therapy on GCF Antioxidant Capacity and MMP-9 in Stage II Periodontitis Patients: A Randomized Controlled Clinical Trial. Int J Dent 2021:8840167\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMontero J, L\u0026oacute;pez-Valverde N, Ferrera MJ, L\u0026oacute;pez-Valverde A (2017) Changes in crevicular cytokines after application of melatonin in patients with periodontal disease. J Clin Exp Dent 9(9):e1081\u0026ndash;e1087\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEl-Gammal MY, Salem AS, Anees MM, Tawfik MA (2016) Clinical and Radiographic Evaluation of Immediate Loaded Dental Implants With Local Application of Melatonin: A Preliminary Randomized Controlled Clinical Trial. J Oral Implantol 42(2):119\u0026ndash;125\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRenn T-Y, Huang Y-K, Feng S-W, Wang H-W, Lee W-F, Lin C-T et al (2018) Prophylactic supplement with melatonin successfully suppresses the pathogenesis of periodontitis through normalizing RANKL/OPG ratio and depressing the TLR4/MyD88 signaling pathway. J Pineal Res. ; 64(3)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTakechi M, Tatehara S, Satomura K, Fujisawa K, Nagayama M (2008) Effect of FGF-2 and melatonin on implant bone healing: a histomorphometric study. J Mater Sci: Mater Med 19:2949\u0026ndash;2952\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSalom\u0026oacute;-Coll O, de Mat\u0026eacute;-S\u0026aacute;nchez JE, Ram\u0026iacute;rez-Fern\u0026aacute;ndez MP, Satorres-Nieto M, Gargallo-Albiol J, Calvo-Guirado JL (2016) Osseoinductive elements for promoting osseointegration around immediate implants: A pilot study in the foxhound dog. Clin Oral Implant Res 27:e167\u0026ndash;e175\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDundar S, Yaman F, Saybak A, Ozupek MF, Toy VE, Gul M et al (2016) Evaluation of Effects of Topical Melatonin Application on Osseointegration of Dental Implant: An Experimental Study. J Oral Implantol 42(5):386\u0026ndash;389\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCalvo-Guirado JL, Aguilar Salvatierra A, Gargallo-Albiol J, Delgado-Ruiz RA, Mat\u0026eacute; Sanchez JE, Satorres-Nieto M (2015) Zirconia with laser-modified microgrooved surface vs. titanium implants covered with melatonin stimulates bone formation. Experimental study in tibia rabbits. Clin Oral Implants Res 26(12):1421\u0026ndash;1429\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGuardia J, G\u0026oacute;mez-Moreno G, Ferrera MJ, Cutando A (2011) Evaluation of effects of topic melatonin on implant surface at 5 and 8 weeks in Beagle dogs. Clin Implant Dent Relat Res 13:262\u0026ndash;268\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHazzaa HH, El-Kilani NS, Elsayed SA, Abd El Massieh PM (2019) Evaluation of immediate implants augmented with autogenous bone/melatonin composite graft in the esthetic zone: a randomized controlled trial. J Prosthodont 28:637\u0026ndash;642\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDe Waal YC, Eijsbouts HV, Winkel EG, van Winkelhoff AJ (2017) Microbial Characteristics of Peri-Implantitis: A Case-Control Study. J Periodontol 88(2):209\u0026ndash;217\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCanullo L, Pe\u0026ntilde;arrocha-Oltra D, Covani U, Rossetti PH (2015 Jul-Aug) Microbiologic and Clinical Findings of Implants in Healthy Condition and with Peri-Implantitis. Int J Oral Maxillofac Implants 30(4):834\u0026ndash;842\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJezdic M, Nikolic N, Krasavcevic AD, Milasin J, Aleksic Z, Carkic J et al (2023) Clinical, microbiological and osteoimmunological findings in different peri-implant conditions - A cross-sectional study. Clin Oral Implants Res 34(9):958\u0026ndash;966\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEbadian AR, Kadkhodazadeh M, Zarnegarnia P, Dahl\u0026eacute;n G (2012) Bacterial analysis of peri-implantitis and chronic periodontitis in Iranian subjects. Acta Med Iran 50(7):486\u0026ndash;492\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKorsch M, Marten SM, Stoll D, Prechtl C, D\u0026ouml;tsch A (2021) Microbiological findings in early and late implant loss: an observational clinical case-controlled study. BMC Oral Health 21(1):112\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSanz-Martin I, Doolittle-Hall J, Teles RP, Patel M, Belibasakis GN, H\u0026auml;mmerle CHF et al (2017) Exploring the microbiome of healthy and diseased peri-implant sites using Illumina sequencing. J Clin Periodontol 44(12):1274\u0026ndash;1284\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDing Q, Tan KS (2016) The Danger Signal Extracellular ATP Is an Inducer of Fusobacterium nucleatum Biofilm Dispersal. Front Cell Infect Microbiol 6:155\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGhensi P, Manghi P, Zolfo M, Armanini F, Pasolli E, Bolzan M et al (2020) Strong oral plaque microbiome signatures for dental implant diseases identified by strain-resolution metagenomics. NPJ Biofilms Microbiomes 6(1):47\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHan YW (2015) Fusobacterium nucleatum: a commensal-turned pathogen. Curr Opin Microbiol 23:141\u0026ndash;147\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePolak D, Wilensky A, Shapira L, Halabi A, Goldstein D, Weiss EI et al (2009) Mouse model of experimental periodontitis induced by Porphyromonas gingivalis/Fusobacterium nucleatum infection: bone loss and host response. J Clin Periodontol 36(5):406\u0026ndash;410\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHe F, Wu X, Zhang Q, Li Y, Ye Y, Li P, Chen S, Peng Y, Hardeland R, Xia Y (2021) Bacteriostatic Potential of Melatonin: Therapeutic Standing and Mechanistic Insights. Front Immunol 12:683879\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang HX, Liu F, Ng TB (2001) Examination of pineal indoles and 6-methoxy-2-benzoxazolinone for antioxidant and antimicrobial effects. Comp Biochem Physiol C Toxicol Pharmacol 130(3):379\u0026ndash;388\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTekbas OF, Ogur R, Korkmaz A, Kilic A, Reiter RJ (2008) Melatonin as an antibiotic: new insights into the actions of this ubiquitous molecule. J Pineal Res 44(2):222\u0026ndash;226\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhou W, Zhang X, Zhu CL, He ZY, Liang JP, Song ZC (2016) Melatonin Receptor Agonists as the Perioceutics Agents for Periodontal Disease through Modulation of Porphyromonas gingivalis Virulence and Inflammatory Response. PLoS ONE 11(11):e0166442\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"melatonin, periimplant disease, marginal bone loss, inflammation, treatment","lastPublishedDoi":"10.21203/rs.3.rs-7095643/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7095643/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjectives\u003c/strong\u003e: The main objective was to determine the effectiveness of melatonin in the treatment of peri-implantitis. Secondary objectives were to determine the anti-inflammatory, osteogenic and antimicrobial properties of melatonin.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods\u003c/strong\u003e: A randomized clinical trial was carried out in patients affected by peri-implantitis with a follow-up of 60 days. Melatonin 1.9 mg or placebo was applied locally to the peri-implant defect after debridement. The probing depth, bleeding index, plaque index, and interleukin-1β and 6 concentrations, peri-implant bone level and the bacterial strains were analyzed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: 30 patients were analyzed with a mean age of 71.9±7.3 years. Changes on the probing depth in the melatonin group were -1.80±0.88 mm and -1.38±0.47 mm in placebo. Bone level changes were -0.87±0.74 mm in the melatonin group and -0.80±0.68 mm in the placebo. The interleukin-1β concentration at 60 days was 8.62±5.09 pg/mL in the melatonin group and 9.07±5.57 pg/mL in placebo. No differences were observed in probing depth (p=.17), plaque index (p=.57), bleeding index (p=.91), peri-implant bone level (p=.43), interleukin-1β (p=.80), interleukin-6 (p=.52) and anaerobic bacterial species (p=0.96). There were differences in the P. gingivalis concentration (p=.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e: Anti-inflammatory, analgesic, osteogenic and antimicrobial properties of melatonin cannot be determined. It seems to improve slightly probing depth changes, interleukin-1β levels and P. gingivalis concentration.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration\u003c/strong\u003e: Protocol Registration \u0026amp; Results System Clinical Trial Number NCT06816277-\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Relevance: \u003c/strong\u003eMelatonin could improve plaque index, bleeding index, reduce probing depth and peri-implant marginal bone loss, in addition to controlling certain bacterial species in the short term.\u003c/p\u003e","manuscriptTitle":"Application of local melatonin for controlling peri-implantitis: a randomized clinical trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-07 06:51:26","doi":"10.21203/rs.3.rs-7095643/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1b2560f4-8729-42a9-aa8f-d150b3425510","owner":[],"postedDate":"August 7th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-10T10:53:52+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-07 06:51:26","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7095643","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7095643","identity":"rs-7095643","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}