The effect of chlorhexidine mouthwash on gingival health around stainless steel crowns in primary molars

The effect of chlorhexidine mouthwash on gingival health around stainless steel crowns in primary molars | 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 The effect of chlorhexidine mouthwash on gingival health around stainless steel crowns in primary molars Taravati Shirin¹, Basir Leila², Motaghi Shiva³, Sana Ghaedi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7058941/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Apr, 2026 Read the published version in BMC Oral Health → Version 1 posted 17 You are reading this latest preprint version Abstract Aim: Stainless steel crowns (SSC), widely used in pediatric dentistry, may cause gingivitis and discomfort. In this study, we investigated the effect of these crowns on gingival index (GI), periodontal probing depth (PPD), Oral Hygiene Index-Simplified (OHI-S), and the effect of chlorhexidine (CHX) mouthwash on reducing these indices in crowned teeth. Materials and Methods: A randomized double-blind controlled trial was conducted on 56 healthy children aged 4 to 9 years old requiring pulpotomy and SSC on mandibular primary molars. Patients were randomly divided into control and intervention (using chlorhexidine mouthwash) groups. In the second session, two weeks later, GI, OHI-S, and PPD were measured in previously crowned and controlled teeth. Statistical analysis: Non-parametric tests Mann-Whitney and Wilcoxon were used to analyze OHI-S, PPD, and GI scores between groups. Results: Comparing SSC-restored teeth between the intervention and control groups showed OHI-S and GI indices were lower in the intervention group and this difference was significant (P = 0.004), (P=0.003), however PPD in crowned teeth did not differ significantly between the two groups (P> 0.05). In the control group, GI and PPD increased significantly in crowned teeth, while plaque accumulation remained unchanged. In contrast, the CHX group showed no significant differences between crowned and control teeth. Conclusion: Chlorhexidine mouthwash usage improved gingival health, and decreased plaque accumulation. Therefore, providing instructions about using mouthwash after placing SSCs especially in patients with poor oral hygiene is recommended. Trial registration: This trial was registered at the Iranian Registry of Clinical Trials (IRCT) on April 17, 2021, under registration number IRCT20210417050994N1. Stainless steel crown Oral Hygiene Index Gingivitis Figures Figure 1 Figure 2 Figure 3 Introduction Stainless steel crowns were first introduced to pediatric dentistry by Humphry in 1950. These crowns are valuable for restoring severely damaged primary teeth and especially recommended for younger children who are at high risk of dental caries. SSCs advantages include durability, longevity, prevention of recurrent caries in children and cost-effectiveness [ 1 , 2 ]. Stainless steel crowns are available in different sizes and are trimmed and contoured to match specific teeth as needed. Due to the fact that there is no perfect marginal integrity in these crowns, periodontal problems happen occasionally which causes discomfort to the patients. Periodontal problems accompanying SSCs are commonly seen in the form of gingivitis [ 3 , 4 ]. Among the local factors, any factor that causes plaque accumulation on the teeth or interferes with plaque removal can lead to gingivitis, so over-contoured crowns and crowns which extend under the gingiva can lead to gingivitis. Gingivitis is reversible and can be controlled by improving oral hygiene [ 5 ]. The use of chemical mouthwashes along with mechanical plaque removal helps to reduce microbial plaque and gingivitis and can promote oral hygiene [ 6 ]. Chlorhexidine (CHX) is a cationic bisbiguanide with broad antimicrobial activity and has been used as the gold standard for dental plaque control in dentistry for more than two decades. It exerts its antimicrobial activity by rupture of the cell membrane of microorganisms. CHX has an exclusive property which can be bonded to human tissue proteins. Therefore, the substance is slowly released and leads to long-term antimicrobial activity against gram-positive, gram-negative bacteria and fungi [ 7 ]. CHX has been studied in dentistry as a smooth surface caries controller, denture disinfectant, and plaque control agent [ 8 ]. There are studies that have been performed to show periodontal problems and plaque accumulation around preformed crowns in primary teeth. [ 9 , 10 , 11 ]. Sharaf et al. concluded that stainless steel crowns do not have adverse effects on gingiva in patients with good oral hygiene [ 4 ]. Given the fact that gingivitis is one of the most common problems of stainless-steel crowns in primary teeth [ 4 , 10 ], no study has examined the effect of therapeutic agents and mouthwashes in reducing gingivitis around these crowns. The aim of this study was to evaluate the effect of CHX mouthwash on gingival health and reduction of gingivitis around SSCs in children post treatment. Materials and Methods A randomized double blinded controlled trial was conducted on 56 healthy children of age group 4 to 9 years. Participants were recruited from referrals to Jundishapur dental school in Ahvaz, IRAN from October 2020 to March 2021. In the first examination, Patients with carious mandibular primary molars that needed pulpotomy and SSC were selected. The inclusion criteria for the study were: Children over 4 years of age who were able to spit out mouthwash, no history of taking antibiotics within the past 2 weeks, no signs of periodontal disease and interdental bone resorption on the patient's radiograph, having no orthodontic appliance, no history of systemic disease, no history of fluoride therapy in the last two weeks, no use of mouthwash within the previous 4 weeks. The exclusion criteria were: Non-cooperative behavior, use of antibiotics during treatment, receiving dental treatments in other medical centers, or failure to use CHX mouthwash as recommended. Children and their parents were given verbal and written information. Informed consent was obtained from the parents prior to the study. Ethical permission for the study was approved by the Ahvaz Jundishapur University of medical sciences Ethics Committee, according to the Helsinki Declaration of 1975, as revised in 2000. (Ethical code: IR.A.JUMS.REC.1400.036) At the first session, the mandibular primary molar of one side was treated based on the patient’s chief complaint. After pulpotomy, the teeth were prepared and the SSCs (3M ESPE, Seefeld, Germany), (MIB, Korea) with appropriate matching (after trimming and contouring if needed) was selected and cemented using GI (luting and lining, GC corp, Japan) cement. A trained pediatric dentistry resident did pulpotomy and SSCs and the gingival margins of all SSCs were extended 0.5-1 mm subgingivally. For each patient a blind pediatric dentist assessed baseline status of oral hygiene by measuring Gingival index (GI), Oral hygiene Index-Simplified (OHI-S) and Periodontal Probing Depth (PPD) of teeth. OHI-S measured by moving the side of an explorer on teeth no 55, 51, 65, 75, 71 and 85 and determining the amount of plaque accumulation. OHI-S surveyed the sum of debris index (DI) and calculus index (CI), but in our study since there was no calculus formation in patients, the OHI-S was assumed the same as DI. OHI-S was scored as 0 = No debris on the tooth surface, 1 = Soft debris does not exceed one third of the tooth surface, 2 = Soft debris covers more than one third of the tooth surface, but does not exceed two thirds of the tooth surface, 3 = Soft debris covers more than two thirds of the tooth surface [ 12 ]. GI and PPD were determined by a periodontal probe (D&P, IRAN), placed in mesial, distal, buccal and lingual sulcus of crowned and control teeth. Gingival index was measured as follows: 0 = Healthy gums, 1 = Low inflammation: low discoloration, low edema, no bleeding, 2 = Moderate inflammation: redness of the gums, edema and shine, bleeding gums during probing, 3 = Severe inflammation: marked redness and edema, sores, tendency to spontaneous bleeding gums [ 13 ]. In patients with two adjacent primary molars needing SSCs, the second primary molar was included in the study. Then patients were randomly divided into two groups, control and intervention (CHX mouthwash), random allocation was conducted by the lead investigator using a consecutive allocation method, based on a simple random number table. No formal allocation concealment mechanism was used. (Fig. 1 ). No mouthwash was prescribed in the control group and no additional measures were taken to improve the children’s oral health. In the intervention group, patients were instructed to use 10 ml of 0.2% CHX spearmint mouthwash (Vi-One, IRAN) twice daily. They were advised to swish the mouthwash for 60 seconds before spitting it out. Patients were also warned not to swallow mouthwash and to avoid eating and drinking for 30 minutes after using mouthwash. Patients did not know the type of mouthwash and it was provided to them in a special container. No attempt was made to influence the oral health of children to investigate the effect of mouthwash alone. In both groups, two weeks after the first appointment, GI, OHI-S, and PPD were remeasured in previously crowned teeth and the control tooth on the opposite side of the patient's jaw (the same antimere tooth without crown). Patients were asked whether they had used the mouthwash, and eight children who did not use it due to lack of cooperation were excluded from the experimental group. Patients in the control group were also asked about the history of using mouthwash and were excluded if they had used it. (Fig. 2 , 3 ) Statistical analysis The data were collected and analyzed for statistical analysis by using SPSS software version 20 (SPSS Inc., USA). The sample size was based on feasibility and the number of eligible participants referred to the dental school during the study period. The coefficient of reproducibility of the variables was calculated by the Correlations test in order to measure the reproducibility of the dentist's measurements and was above 85% for all variables. The data of each group were evaluated by Kolmogorov-Smirnov test to be evaluated for normality. As the data were not normally distributed, non-parametric tests, Mann-Whitney and Wilcoxon were used to analyze OHI-S, PPD, and GI scores. The significance level was set as P < 0.05. Results In our study, OHI-S, GI and PPD in crowned teeth in the control and intervention groups (CHX mouthwash) were examined. According to our data 62% of the patients in the control group and 21.4% of the patients in the CHX group showed gingival inflammation and higher GI index after placing SSCs. Comparing indices between groups, OHI-S and GI indices in the CHX group was lower than the control group and its effect was statistically significant. (P = 0.004) (P = 0.003) Also, PPD decreased in patients who used CHX mouthwash, but the difference was not statistically significant. (P > 0.05) (Table 1 ) Table 1 Comparison of OHI-S, GI and PD in crowned primary molars in CHX and control groups Groups p-value Chlorhexidine Control Gingivitis 21.4% 62% Indices mean SD mean SD 0.004* OHI-S 1.23 0.67 1.64 0.85 GI 0.64 0.82 1.46 1.03 0.003* PD 0.54 0.51 1.65 0.65 0.55 c orrelation is significant at the P < 0.05 level. *Correlation is significant. OHI-S, oral hygiene index simplified; GI, gingival index; PPD, periodontal probing depth The intragroup evaluations between crowned and natural teeth showed in Table 2 . In the control group, the plaque accumulation was lower on the SSC, but the difference was not statistically significant (P > 0.05) and The GI index and PPD were significantly increased in crowned teeth. (P 0.05), unless plaque accumulation on crowns was more than natural teeth (P = 0). Table 2 Intragroup comparison of plaque accumulation, GI and PD in restored and natural teeth in both groups Indices Groups Restored teeth Natural teeth Mean SD Mean SD p-value Plaque accumulation CHX 1.23 0.67 0.97 0.59 0.000* Control 1.64 0.85 1.71 0.71 0.49 GI CHX 0.64 0.82 0.35 0.82 0.2 Control 1.46 0.35 1.46 1.03 0.000* PPD CHX 1.54 0.5 1.33 0.51 0.109 Control 1.65 0.65 1.32 0.49 0.006* c orrelation is significant at the P < 0.05 level. *Correlation is significant. GI, gingival index; PPD, periodontal probing depth So, the effect of chlorhexidine mouthwash was significant when comparing control and experimental groups, and in intragroup evaluation only control groups showed higher GI and PPD, also GI and PPD were not significantly higher than natural teeth in the CHX group. Discussion Based on previous studies, gingivitis, swelling and bleeding around the SSCs, led to pain and patient dissatisfaction [ 10 , 14 ]. So, the aim of this study was to compare OHIS, GI and PPD indices between the intervention group who used chlorhexidine mouthwash after SSC placement and the control group who did not use mouthwash. Another aim of this study was to compare these indices between natural and crowned teeth to assess the impact of SSCs on gingival health. Both groups were evaluated two weeks after treatment to assess the indices. Assessing the factors affecting gingivitis In our study, 62% of patients in the control group showed gingivitis and the GI index in crowned teeth was higher than control teeth. Similar to our results, Belduz Kara’s study also showed that the gingival health around the control teeth was better than SSCs [ 14 ]. Also, in the study of Schüler et al., the major concern about SSCs was the presence of gingivitis, so that 72.1% of all SSCs showed bleeding after Probing and gingivitis [ 10 ]. To manage gingival problems, we must first address the causes. One of the causes of gingivitis around the SSC is improper treatment technique [ 15 , 16 ]. The absence of gingival marginal integration of crowns and incomplete removal of cement are effective factors in this regard. According to other studies, it has been shown that the gingival index in non-ideal and defective crowns with problems such as poor marginal integrity and loss of crown crimping was significantly higher than the control teeth [ 3 , 4 ]. Therefore, the dentist's skill in placing SSCs can affect the rate of gingivitis after treatment. In our study, all SSCs were placed by a trained pediatric dentistry resident, so technical errors such as improper size, over extended crowns, or open interdental contacts were less likely. However, even in appropriate SSCs, there is some degree of gingivitis, so in addition to the skill of the dentist, it seems that the patient's oral hygiene is an important factor in development of gingivitis around the SSCs. In our study, this was evaluated by assessing the OHI-S and plaque accumulations on teeth and the results showed that gingivitis was observed in 40% of patients whose OHI-S index was above zero. Similarly in other studies children with poor oral hygiene showed a higher incidence of gingivitis, while children with good oral health had healthy gingival tissue around their SSCs and a positive and significant relationship between supragingival plaque and gingivitis has seen [ 4 , 17 ]. It may also appear that the presence of the crowns in the gingival sulcus may cause gingivitis. But studies showed that the cause of inflammation is bacterial plaque formed on the surface of the crowns, and the mechanical stimulation made by the edge of the crowns is not effective solely [ 17 , 18 ]. Also in our study, the amount of plaque accumulation on SSCs in the control group was not significantly different from teeth without SSCs. Similar to the results of our study, other studies have shown that there is no increase in supra-gingival plaque accumulation associated with SSCs [ 9 , 15 , 19 ] Likewise, by enhancing patients’ oral hygiene, the placement of SSCs will cause less inflammation and discomfort. In this regard, in our study CHX mouthwash was used to reduce plaque accumulation and subsequently reduce the risk of gingival problems after SSC placement. The effect of CHX mouthwash on OHI-S, GI and PPD indices In the CHX group, the OHI-S and GI showed a statistically significant decrease compared to the control group. In line with our results in other studies, the use of CHX has led to a decrease in plaque accumulation and GI [ 8 , 20 ]. This can be attributed to the antibacterial properties of CHX. Therefore, it seems that CHX mouthwash prevents gingivitis around SSCs by reducing plaque accumulation and antibacterial properties [ 21 ]. However, the PPD decreased in our study, this difference was not statistically significant, which may be due to the reduced incidence of periodontal disease in children and the higher prevalence of gingivitis in them, which leads to disclosing the symptoms of gingival problems in the form of bleeding during probing and pain, as shown in GI [ 5 ]. In our study, two weeks the use of CHX has advantages in reducing gingival problems. Considering that time can be an effective factor in increasing gingivitis, there are conflicting results regarding the time and extent of gingivitis after crown placement [ 14 ]. In some studies, longer periods of following up had no significant effect on the results, so probably time couldn’t affect results significantly, but studies with longer follow up recommended [ 4 , 10 ]. Moreover, the continuous effect of CHX after stopping its use has shown [ 22 ]. In other studies, longer periods of using CHX mouthwash in children assessed and reduced the GI index. [ 8 , 20 ] Due to the problems of children's cooperation in this study, the duration of using mouthwash was limited. Also, the likelihood of side effects such as discoloration, calculus formation and changes in taste sensation increases by time [ 23 ]. In our study, health education and emphasis on mechanical removal of plaque was not given to patients, in order to eliminate the effect of the interventional variable of changing the brushing method, this raises the possibility that with proper mechanical oral hygiene methods such as toothbrushing and flossing or after oral hygiene instruction, the effect of mouthwash would be less. But in Charles's study, patients had a course of oral hygiene education before the study, and all entered the study in a similar situation at time zero. After six months, the GI and PD indices of the intervention group that used mouthwash were statistically lower [ 20 ]. This proves that the use of mouthwash independent of mechanical plaque removal methods improves the patient's gingival condition [ 23 ]. In this study, due to financial and time constraints, we only investigated the effect of CHX mouthwash on gingival status of teeth restored by stainless steel crowns. Considering the fact that in our study, a limited number of patients complained about the taste of mouthwash or used mouthwash only once and later excluded from the study, it is recommended to use other mouthwashes and evaluate their effects. Nonetheless, comparing CHX with other types of mouthwashes, most studies approved the superior effect of CHX in reducing plaque and gingivitis [ 21 , 22 , 24 ]. Also, In cheng study, chlorhexidine mouthwash is well tolerated by children over 6 years and has an acceptable compliance [ 25 ]. In our study, high quality SSCs were studied, but given the fact that mouthwashes are better at removing microbial plaque in areas without proper access, the use of mouthwashes will probably have a better effect on crowns that do not fully integrate to teeth completely. This issue should be considered in future investigations. Conclusion In this study chlorhexidine mouthwash usage improved gingival health, and decreased plaque accumulation on teeth after placing SSCs. So, giving instructions about using mouthwash after placing SSCs especially in patients with poor oral hygiene is recommended. Abbreviations SSC Stainless Steel Crown CHX Chlorhexidine OHI-S Oral Hygiene Index-Simplified GI Gingival Index PPD Periodontal Probing Depth Declarations Funding This project has been supported by Ahvaz Jundishapur University of Medical Sciences Research Center grant #U-00033. Conflict of interest The authors declare that they have no conflict of interest related to this study. Ethics approval and Consent to participate Approval was obtained from the Ethics Committee of Ahvaz Jundishapur University of Medical Sciences (IR.A.JUMS.REC. 1400.036). Written informed consent was obtained from the parents or legal guardians of all participants included in the study. Consent for publication Not applicable. Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Authors' contributions TS and LB designed the study. SM performed the clinical procedures. SG analyzed the data and drafted the manuscript. All authors reviewed and approved the final manuscript. Acknowledgements The authors would like to thank the staff and patients of Jundishapur Dental School for their cooperation. Clinical Trial Registration This trial was registered at the Iranian Registry of Clinical Trials (IRCT) under the registration number: IRCT20210417050994N1. Protocol availability No formal trial protocol was prepared for publication. However, the methods and procedures are described in detail in the Materials and Methods section of this manuscript. References Attari N, Roberts JF. Restoration of primary teeth with crowns: a systematic review of the literature. Eur J Paediatr Dent. 2006;1(2):58–62. Waggoner WF, Nelson T. Restorative dentistry for the primary dentition. In: Pediatric Dentistry, 6th ed, Philadelphia: Elsevier, pp. 304–28. Chao DD, Tsai TP, Chen TC. Clinical evaluation of gingival tissue restored with stainless steel crown. Changgeng Yi Xue Za Zhi. 1992;15(4):198–203. Sharaf AA, Farsi NM. A clinical and radiographic evaluation of stainless steel crowns for primary molars. J Dent. 2004;32(1):27–33. Stenberg WV Jr. Periodontal problems in children and adolescents. Pediatric Dentistry. 6th ed. Philadelphia: Elsevier; 2019. pp. 371–8. Moretti LA, Barros RR, Costa PP, et al. 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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-7058941","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":502101776,"identity":"c31c21a0-c45b-402b-9de4-12ab4edead62","order_by":0,"name":"Taravati Shirin¹","email":"","orcid":"","institution":"Ahvaz Jundishapur University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Taravati","middleName":"","lastName":"Shirin¹","suffix":""},{"id":502101777,"identity":"84df386d-b371-4764-8cb8-59c2c25da200","order_by":1,"name":"Basir Leila²","email":"","orcid":"","institution":"Ahvaz Jundishapur University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Basir","middleName":"","lastName":"Leila²","suffix":""},{"id":502101778,"identity":"9c65cbe8-a33d-4b1c-8c2d-bf46cf3d3834","order_by":2,"name":"Motaghi Shiva³","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8ElEQVRIiWNgGAWjYBAC+RmMDVAmD8OBDwwMCQS1GNyAaJEAaTk4gygtEhAarIWZhygt0s1tEj9zbOr4+9cePGzbZpfHz97A+OFjDm4t8nMOtkn2bkuTkLjxLuFwbltysWTPAWbJmdvwWHMjsdmAd9thCYYbZwyAWpgTN9xIYGPmJaDF8C9QizxIi2VbPVFaGh+DbDE432NwmLHtMGEtBiAtstvSJDfe4DE42HPueOLMnoPNeP0iPyP9wcG322z45c6fMf7wo6w6sZ+9+eCHj/gcBgcSCQwMjGwgFjw9EAL8B4DEHyIVj4JRMApGwYgCAB72XIhmrtIMAAAAAElFTkSuQmCC","orcid":"","institution":"Ahvaz Jundishapur University of Medical Sciences","correspondingAuthor":true,"prefix":"","firstName":"Motaghi","middleName":"","lastName":"Shiva³","suffix":""},{"id":502101779,"identity":"5eb4468a-eb48-4478-91c4-cdbd991fb38a","order_by":3,"name":"Sana Ghaedi","email":"","orcid":"","institution":"Ahvaz Jundishapur University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Sana","middleName":"","lastName":"Ghaedi","suffix":""}],"badges":[],"createdAt":"2025-07-06 16:08:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7058941/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7058941/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12903-026-07902-w","type":"published","date":"2026-04-28T15:57:18+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":89544176,"identity":"5d5697b9-c7da-4de6-a0f0-125b22adf806","added_by":"auto","created_at":"2025-08-21 06:57:59","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":52443,"visible":true,"origin":"","legend":"\u003cp\u003eflowchart of study design\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7058941/v1/56506f3b4dbd43fdac15e963.jpg"},{"id":89544177,"identity":"0aa408c3-06ea-4d1a-8f67-55024aa5e964","added_by":"auto","created_at":"2025-08-21 06:58:00","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":191031,"visible":true,"origin":"","legend":"\u003cp\u003eThe treatment of mandibular right second primary molar. (A) before treatment (B) clinical view of tooth after pulp therapy and preparation for SSC (c) the clinical view immediately after placing SSC\u003c/p\u003e","description":"","filename":"figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7058941/v1/97f50a08218a72341b9883f3.jpg"},{"id":89542781,"identity":"17ff6009-1161-441a-920d-35e1a402af6f","added_by":"auto","created_at":"2025-08-21 06:49:59","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":123701,"visible":true,"origin":"","legend":"\u003cp\u003eclinical images of primary molars 2 weeks after placing SSCs, (A): plaque accumulation on tooth no.75, soreness of gingiva is visible (B): healthy gingiva around tooth no.84 comparing to control tooth, (C): plaque accumulation and bleeding on probing (BOP) around SSCs, (D): clinical situation of SSCs\u003c/p\u003e","description":"","filename":"figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7058941/v1/84ee7ab6eb5b113cffaa5215.jpg"},{"id":108438849,"identity":"afab7fce-9db2-451c-ab33-66781c5749d7","added_by":"auto","created_at":"2026-05-04 16:10:54","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":599608,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7058941/v1/116e803c-2635-4224-bfa4-5fa0b6e3b795.pdf"},{"id":89544175,"identity":"54d79860-f774-4b6a-a266-9ac7f50b6904","added_by":"auto","created_at":"2025-08-21 06:57:59","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":28180,"visible":true,"origin":"","legend":"","description":"","filename":"CONSORT2010Checklist.docx","url":"https://assets-eu.researchsquare.com/files/rs-7058941/v1/8817c2adfcb0a5bb3090983e.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The effect of chlorhexidine mouthwash on gingival health around stainless steel crowns in primary molars","fulltext":[{"header":"Introduction","content":"\u003cp\u003eStainless steel crowns were first introduced to pediatric dentistry by Humphry in 1950. These crowns are valuable for restoring severely damaged primary teeth and especially recommended for younger children who are at high risk of dental caries. SSCs advantages include durability, longevity, prevention of recurrent caries in children and cost-effectiveness [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Stainless steel crowns are available in different sizes and are trimmed and contoured to match specific teeth as needed. Due to the fact that there is no perfect marginal integrity in these crowns, periodontal problems happen occasionally which causes discomfort to the patients. Periodontal problems accompanying SSCs are commonly seen in the form of gingivitis [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Among the local factors, any factor that causes plaque accumulation on the teeth or interferes with plaque removal can lead to gingivitis, so over-contoured crowns and crowns which extend under the gingiva can lead to gingivitis. Gingivitis is reversible and can be controlled by improving oral hygiene [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. The use of chemical mouthwashes along with mechanical plaque removal helps to reduce microbial plaque and gingivitis and can promote oral hygiene [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eChlorhexidine (CHX) is a cationic bisbiguanide with broad antimicrobial activity and has been used as the gold standard for dental plaque control in dentistry for more than two decades. It exerts its antimicrobial activity by rupture of the cell membrane of microorganisms.\u003c/p\u003e\u003cp\u003eCHX has an exclusive property which can be bonded to human tissue proteins. Therefore, the substance is slowly released and leads to long-term antimicrobial activity against gram-positive, gram-negative bacteria and fungi [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. CHX has been studied in dentistry as a smooth surface caries controller, denture disinfectant, and plaque control agent [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. There are studies that have been performed to show periodontal problems and plaque accumulation around preformed crowns in primary teeth. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSharaf et al. concluded that stainless steel crowns do not have adverse effects on gingiva in patients with good oral hygiene [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eGiven the fact that gingivitis is one of the most common problems of stainless-steel crowns in primary teeth [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], no study has examined the effect of therapeutic agents and mouthwashes in reducing gingivitis around these crowns.\u003c/p\u003e\u003cp\u003eThe aim of this study was to evaluate the effect of CHX mouthwash on gingival health and reduction of gingivitis around SSCs in children post treatment.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eA randomized double blinded controlled trial was conducted on 56 healthy children of age group 4 to 9 years. Participants were recruited from referrals to Jundishapur dental school in Ahvaz, IRAN from October 2020 to March 2021. In the first examination, Patients with carious mandibular primary molars that needed pulpotomy and SSC were selected.\u003c/p\u003e\u003cp\u003eThe inclusion criteria for the study were: Children over 4 years of age who were able to spit out mouthwash, no history of taking antibiotics within the past 2 weeks, no signs of periodontal disease and interdental bone resorption on the patient's radiograph, having no orthodontic appliance, no history of systemic disease, no history of fluoride therapy in the last two weeks, no use of mouthwash within the previous 4 weeks.\u003c/p\u003e\u003cp\u003eThe exclusion criteria were: Non-cooperative behavior, use of antibiotics during treatment, receiving dental treatments in other medical centers, or failure to use CHX mouthwash as recommended. Children and their parents were given verbal and written information. Informed consent was obtained from the parents prior to the study. Ethical permission for the study was approved by the Ahvaz Jundishapur University of medical sciences Ethics Committee, according to the Helsinki Declaration of 1975, as revised in 2000. (Ethical code: IR.A.JUMS.REC.1400.036)\u003c/p\u003e\u003cp\u003eAt the first session, the mandibular primary molar of one side was treated based on the patient\u0026rsquo;s chief complaint. After pulpotomy, the teeth were prepared and the SSCs (3M ESPE, Seefeld, Germany), (MIB, Korea) with appropriate matching (after trimming and contouring if needed) was selected and cemented using GI (luting and lining, GC corp, Japan) cement. A trained pediatric dentistry resident did pulpotomy and SSCs and the gingival margins of all SSCs were extended 0.5-1 mm subgingivally. For each patient a blind pediatric dentist assessed baseline status of oral hygiene by measuring Gingival index (GI), Oral hygiene Index-Simplified (OHI-S) and Periodontal Probing Depth (PPD) of teeth. OHI-S measured by moving the side of an explorer on teeth no 55, 51, 65, 75, 71 and 85 and determining the amount of plaque accumulation. OHI-S surveyed the sum of debris index (DI) and calculus index (CI), but in our study since there was no calculus formation in patients, the OHI-S was assumed the same as DI. OHI-S was scored as 0\u0026thinsp;=\u0026thinsp;No debris on the tooth surface, 1\u0026thinsp;=\u0026thinsp;Soft debris does not exceed one third of the tooth surface, 2\u0026thinsp;=\u0026thinsp;Soft debris covers more than one third of the tooth surface, but does not exceed two thirds of the tooth surface, 3\u0026thinsp;=\u0026thinsp;Soft debris covers more than two thirds of the tooth surface [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. GI and PPD were determined by a periodontal probe (D\u0026amp;P, IRAN), placed in mesial, distal, buccal and lingual sulcus of crowned and control teeth. Gingival index was measured as follows: 0\u0026thinsp;=\u0026thinsp;Healthy gums, 1\u0026thinsp;=\u0026thinsp;Low inflammation: low discoloration, low edema, no bleeding, 2\u0026thinsp;=\u0026thinsp;Moderate inflammation: redness of the gums, edema and shine, bleeding gums during probing, 3\u0026thinsp;=\u0026thinsp;Severe inflammation: marked redness and edema, sores, tendency to spontaneous bleeding gums [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In patients with two adjacent primary molars needing SSCs, the second primary molar was included in the study. Then patients were randomly divided into two groups, control and intervention (CHX mouthwash), random allocation was conducted by the lead investigator using a consecutive allocation method, based on a simple random number table. No formal allocation concealment mechanism was used. (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). No mouthwash was prescribed in the control group and no additional measures were taken to improve the children\u0026rsquo;s oral health. In the intervention group, patients were instructed to use 10 ml of 0.2% CHX spearmint mouthwash (Vi-One, IRAN) twice daily. They were advised to swish the mouthwash for 60 seconds before spitting it out. Patients were also warned not to swallow mouthwash and to avoid eating and drinking for 30 minutes after using mouthwash. Patients did not know the type of mouthwash and it was provided to them in a special container. No attempt was made to influence the oral health of children to investigate the effect of mouthwash alone. In both groups, two weeks after the first appointment, GI, OHI-S, and PPD were remeasured in previously crowned teeth and the control tooth on the opposite side of the patient's jaw (the same antimere tooth without crown). Patients were asked whether they had used the mouthwash, and eight children who did not use it due to lack of cooperation were excluded from the experimental group. Patients in the control group were also asked about the history of using mouthwash and were excluded if they had used it. (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e,\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eThe data were collected and analyzed for statistical analysis by using SPSS software version 20 (SPSS Inc., USA). The sample size was based on feasibility and the number of eligible participants referred to the dental school during the study period. The coefficient of reproducibility of the variables was calculated by the Correlations test in order to measure the reproducibility of the dentist's measurements and was above 85% for all variables. The data of each group were evaluated by Kolmogorov-Smirnov test to be evaluated for normality. As the data were not normally distributed, non-parametric tests, Mann-Whitney and Wilcoxon were used to analyze OHI-S, PPD, and GI scores. The significance level was set as P\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eIn our study, OHI-S, GI and PPD in crowned teeth in the control and intervention groups (CHX mouthwash) were examined. According to our data 62% of the patients in the control group and 21.4% of the patients in the CHX group showed gingival inflammation and higher GI index after placing SSCs. Comparing indices between groups, OHI-S and GI indices in the CHX group was lower than the control group and its effect was statistically significant. (P\u0026thinsp;=\u0026thinsp;0.004) (P\u0026thinsp;=\u0026thinsp;0.003) Also, PPD decreased in patients who used CHX mouthwash, but the difference was not statistically significant. (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (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\u003eComparison of OHI-S, GI and PD in crowned primary molars in CHX and control groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"8\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"5\" nameend=\"c7\" namest=\"c3\"\u003e\u003cp\u003eGroups\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u003cp\u003eChlorhexidine\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eGingivitis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u003cp\u003e21.4%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e62%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eIndices\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003emean\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eSD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003emean\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eSD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.004*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eOHI-S\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003e0.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.85\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eGI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003e0.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.003*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e0.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003e1.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.55\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"8\"\u003e\u003cb\u003ec\u003c/b\u003eorrelation is significant at the P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 level.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"8\"\u003e*Correlation is significant.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"8\"\u003eOHI-S, oral hygiene index simplified; GI, gingival index; PPD, periodontal probing depth\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe intragroup evaluations between crowned and natural teeth showed in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. In the control group, the plaque accumulation was lower on the SSC, but the difference was not statistically significant (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) and The GI index and PPD were significantly increased in crowned teeth. (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). GI and PPD were not significantly higher than those in natural teeth in the CHX group (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05), unless plaque accumulation on crowns was more than natural teeth (P\u0026thinsp;=\u0026thinsp;0).\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\u003eIntragroup comparison of plaque accumulation, GI and PD in restored and natural teeth in both groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"8\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eIndices\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"6\" nameend=\"c7\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eGroups\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u003cp\u003eRestored teeth\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003eNatural teeth\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eSD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eSD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003ePlaque accumulation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCHX\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003e0.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.000*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003e0.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.49\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eGI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCHX\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003e0.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003e0.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.000*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003ePPD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCHX\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003e1.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.109\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003e1.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.006*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"8\"\u003e\u003cb\u003ec\u003c/b\u003eorrelation is significant at the P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 level.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"8\"\u003e*Correlation is significant.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"8\"\u003eGI, gingival index; PPD, periodontal probing depth\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eSo, the effect of chlorhexidine mouthwash was significant when comparing control and experimental groups, and in intragroup evaluation only control groups showed higher GI and PPD, also GI and PPD were not significantly higher than natural teeth in the CHX group.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eBased on previous studies, gingivitis, swelling and bleeding around the SSCs, led to pain and patient dissatisfaction [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. So, the aim of this study was to compare OHIS, GI and PPD indices between the intervention group who used chlorhexidine mouthwash after SSC placement and the control group who did not use mouthwash. Another aim of this study was to compare these indices between natural and crowned teeth to assess the impact of SSCs on gingival health. Both groups were evaluated two weeks after treatment to assess the indices.\u003c/p\u003e\n\u003ch3\u003eAssessing the factors affecting gingivitis\u003c/h3\u003e\n\u003cp\u003eIn our study, 62% of patients in the control group showed gingivitis and the GI index in crowned teeth was higher than control teeth. Similar to our results, Belduz Kara\u0026rsquo;s study also showed that the gingival health around the control teeth was better than SSCs [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Also, in the study of Sch\u0026uuml;ler et al., the major concern about SSCs was the presence of gingivitis, so that 72.1% of all SSCs showed bleeding after Probing and gingivitis [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. To manage gingival problems, we must first address the causes. One of the causes of gingivitis around the SSC is improper treatment technique [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The absence of gingival marginal integration of crowns and incomplete removal of cement are effective factors in this regard. According to other studies, it has been shown that the gingival index in non-ideal and defective crowns with problems such as poor marginal integrity and loss of crown crimping was significantly higher than the control teeth [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Therefore, the dentist's skill in placing SSCs can affect the rate of gingivitis after treatment. In our study, all SSCs were placed by a trained pediatric dentistry resident, so technical errors such as improper size, over extended crowns, or open interdental contacts were less likely. However, even in appropriate SSCs, there is some degree of gingivitis, so in addition to the skill of the dentist, it seems that the patient's oral hygiene is an important factor in development of gingivitis around the SSCs. In our study, this was evaluated by assessing the OHI-S and plaque accumulations on teeth and the results showed that gingivitis was observed in 40% of patients whose OHI-S index was above zero. Similarly in other studies children with poor oral hygiene showed a higher incidence of gingivitis, while children with good oral health had healthy gingival tissue around their SSCs and a positive and significant relationship between supragingival plaque and gingivitis has seen [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. It may also appear that the presence of the crowns in the gingival sulcus may cause gingivitis. But studies showed that the cause of inflammation is bacterial plaque formed on the surface of the crowns, and the mechanical stimulation made by the edge of the crowns is not effective solely [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Also in our study, the amount of plaque accumulation on SSCs in the control group was not significantly different from teeth without SSCs. Similar to the results of our study, other studies have shown that there is no increase in supra-gingival plaque accumulation associated with SSCs [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eLikewise, by enhancing patients\u0026rsquo; oral hygiene, the placement of SSCs will cause less inflammation and discomfort. In this regard, in our study CHX mouthwash was used to reduce plaque accumulation and subsequently reduce the risk of gingival problems after SSC placement.\u003c/p\u003e\n\u003ch3\u003eThe effect of CHX mouthwash on OHI-S, GI and PPD indices\u003c/h3\u003e\n\u003cp\u003eIn the CHX group, the OHI-S and GI showed a statistically significant decrease compared to the control group. In line with our results in other studies, the use of CHX has led to a decrease in plaque accumulation and GI [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. This can be attributed to the antibacterial properties of CHX. Therefore, it seems that CHX mouthwash prevents gingivitis around SSCs by reducing plaque accumulation and antibacterial properties [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. However, the PPD decreased in our study, this difference was not statistically significant, which may be due to the reduced incidence of periodontal disease in children and the higher prevalence of gingivitis in them, which leads to disclosing the symptoms of gingival problems in the form of bleeding during probing and pain, as shown in GI [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn our study, two weeks the use of CHX has advantages in reducing gingival problems.\u003c/p\u003e\u003cp\u003eConsidering that time can be an effective factor in increasing gingivitis, there are conflicting results regarding the time and extent of gingivitis after crown placement [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In some studies, longer periods of following up had no significant effect on the results, so probably time couldn\u0026rsquo;t affect results significantly, but studies with longer follow up recommended [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Moreover, the continuous effect of CHX after stopping its use has shown [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn other studies, longer periods of using CHX mouthwash in children assessed and reduced the GI index. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] Due to the problems of children's cooperation in this study, the duration of using mouthwash was limited. Also, the likelihood of side effects such as discoloration, calculus formation and changes in taste sensation increases by time [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn our study, health education and emphasis on mechanical removal of plaque was not given to patients, in order to eliminate the effect of the interventional variable of changing the brushing method, this raises the possibility that with proper mechanical oral hygiene methods such as toothbrushing and flossing or after oral hygiene instruction, the effect of mouthwash would be less. But in Charles's study, patients had a course of oral hygiene education before the study, and all entered the study in a similar situation at time zero. After six months, the GI and PD indices of the intervention group that used mouthwash were statistically lower [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. This proves that the use of mouthwash independent of mechanical plaque removal methods improves the patient's gingival condition [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. In this study, due to financial and time constraints, we only investigated the effect of CHX mouthwash on gingival status of teeth restored by stainless steel crowns. Considering the fact that in our study, a limited number of patients complained about the taste of mouthwash or used mouthwash only once and later excluded from the study, it is recommended to use other mouthwashes and evaluate their effects. Nonetheless, comparing CHX with other types of mouthwashes, most studies approved the superior effect of CHX in reducing plaque and gingivitis [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Also, In cheng study, chlorhexidine mouthwash is well tolerated by children over 6 years and has an acceptable compliance [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn our study, high quality SSCs were studied, but given the fact that mouthwashes are better at removing microbial plaque in areas without proper access, the use of mouthwashes will probably have a better effect on crowns that do not fully integrate to teeth completely. This issue should be considered in future investigations.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn this study chlorhexidine mouthwash usage improved gingival health, and decreased plaque accumulation on teeth after placing SSCs. So, giving instructions about using mouthwash after placing SSCs especially in patients with poor oral hygiene is recommended.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eSSC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eStainless Steel Crown\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCHX\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eChlorhexidine\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eOHI-S\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eOral Hygiene Index-Simplified\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eGI\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eGingival Index\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003ePPD\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePeriodontal Probing Depth\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis project has been supported by Ahvaz Jundishapur University of Medical Sciences Research Center grant #U-00033.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no conflict of interest related to this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and Consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eApproval was obtained from the Ethics Committee of Ahvaz Jundishapur University of Medical Sciences (IR.A.JUMS.REC. 1400.036).\u0026nbsp;Written informed consent was obtained from the parents or legal guardians of all participants included in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTS and LB designed the study. SM performed the clinical procedures. SG analyzed the data and drafted the manuscript. All authors reviewed and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank the staff and patients of Jundishapur Dental School for their cooperation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Trial Registration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis trial was registered at the Iranian Registry of Clinical Trials (IRCT) under the registration number: IRCT20210417050994N1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eProtocol availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo formal trial protocol was prepared for publication. However, the methods and procedures are described in detail in the Materials and Methods section of this manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAttari N, Roberts JF. Restoration of primary teeth with crowns: a systematic review of the literature. Eur J Paediatr Dent. 2006;1(2):58\u0026ndash;62.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWaggoner WF, Nelson T. Restorative dentistry for the primary dentition. In: Pediatric Dentistry, 6th ed, Philadelphia: Elsevier, pp. 304\u0026ndash;28.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChao DD, Tsai TP, Chen TC. Clinical evaluation of gingival tissue restored with stainless steel crown. Changgeng Yi Xue Za Zhi. 1992;15(4):198\u0026ndash;203.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSharaf AA, Farsi NM. A clinical and radiographic evaluation of stainless steel crowns for primary molars. J Dent. 2004;32(1):27\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStenberg WV Jr. Periodontal problems in children and adolescents. Pediatric Dentistry. 6th ed. Philadelphia: Elsevier; 2019. pp. 371\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMoretti LA, Barros RR, Costa PP, et al. The influence of restorations and prosthetic crowns finishing lines on inflammatory levels after non-surgical periodontal therapy. J Int Acad Periodontol. 2011;13(3):65\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFardai O, Turnbull RS. A review of the literature on use of chlorhexidine in dentistry. J Am Dent Assoc. 1986;112(6):863\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBajaj N, Tandon S. The effect of Triphala and Chlorhexidine mouthwash on dental plaque, gingival inflammation, and microbial growth. Int J Ayurveda Res. 2011;2(1):29\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlShaibah WM, El-Shehaby FA, El-Dokky NA, et al. Comparative study on the microbial adhesion to preveneered and stainless steel crowns. J Indian Soc Pedod Prev Dent. 2012;30(3):206\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSch\u0026uuml;ler IM, Hiller M, Roloff T, et al. Clinical success of stainless steel crowns placed under general anaesthesia in primary molars: An observational follow up study. J Dent. 2014;42(11):1396\u0026ndash;403.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWalia T, Salami AA, Bashiri R, et al. A randomised controlled trial of three aesthetic full-coronal restorations in primary maxillary teeth. Eur J Paediatr Dent. 2014;15(2):113\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGreene JC, Vermillion JR. The simplified oral hygiene index. J Am Dent Assoc. 1964;68:7\u0026ndash;13.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eL\u0026ouml;e H. The gingival index, the plaque index and the retention index systems. J Periodontol. 1967;38(6):610\u0026ndash;606.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBeld\u0026uuml;z Kara N, Yilmaz Y. Assessment of oral hygiene and periodontal health around posterior primary molars after their restoration with various crown types. Int J Paediatr Dent. 2014;24(4):303\u0026ndash;13.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDurr DP, Ashrafi MH, Duncan WK. A study of plaque accumulation and gingival health surrounding stainless steel crowns. ASDC J Dent Child. 1982;49(5):343\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMacLean JK, Champagne CE, Waggoner WF, et al. Clinical outcomes for primary anterior teeth treated with preveneered stainless steel crowns. Pediatr Dent. 2007;29(5):377\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWaerhaug J. Tissue reactions around artificial crowns. J Periodontol. 1953;24(3):172\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWebber DL. Gingival health following placement of stainless steel crowns. ASDC J Dent Child. 1974;41(3):186\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDimitrov E. Oral hygiene levels in primary molars restored with preformed metal crowns. Scr Sci Med. 2019;5(2):26\u0026ndash;31.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCharles CH, Mostler KM, Bartels LL, et al. Comparative antiplaque and antigingivitis effectiveness of a chlorhexidine and an essential oil mouthrinse: 6-month clinical trial. J Clin Periodontol. 2004;31(10):878\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Leeuwen MP, Van der Slot DE. Essential oils compared to chlorhexidine with respect to plaque and parameters of gingival inflammation: a systematic review. J Periodontol. 2011;82(2):174\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSharma R, Hebbal M, Ankola AV, et al. Effect of two herbal mouthwashes on gingival health of school children. J Tradit Complement Med. 2014;4(4):272\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGagari E, Kabani S. Adverse effects of mouthwash use. A review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1995;80(4):432\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eViana GR, Teiltelbaum AP, dos Santos FA, et al. Chlorhexidine spray as an adjunct in the control of dental biofilm in children with special needs. Spec Care Dentist. 2014;34(6):286\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCheng KK. Children's acceptance and tolerance of chlorhexidine and benzydamine oral rinses in the treatment of chemotherapy-induced oropharyngeal mucositis. Eur J Oncol Nurs. 2004;8(4):341\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Stainless steel crown, Oral Hygiene Index, Gingivitis","lastPublishedDoi":"10.21203/rs.3.rs-7058941/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7058941/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eAim: \u003c/strong\u003eStainless steel crowns (SSC), widely used in pediatric dentistry, may cause gingivitis and discomfort. In this study, we investigated the effect of these crowns on gingival index (GI), periodontal probing depth (PPD), Oral Hygiene Index-Simplified (OHI-S), and the effect of chlorhexidine (CHX) mouthwash on reducing these indices in crowned teeth.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods: \u003c/strong\u003eA randomized double-blind controlled trial was conducted on 56 healthy children aged 4 to 9 years old requiring pulpotomy and SSC on mandibular primary molars. Patients were randomly divided into control and intervention (using chlorhexidine mouthwash) groups. In the second session, two weeks later, GI, OHI-S, and PPD were measured in previously crowned and controlled teeth.\u003c/p\u003e\n\u003cp\u003eStatistical analysis: Non-parametric tests Mann-Whitney and Wilcoxon were used to analyze OHI-S, PPD, and GI scores between groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eComparing SSC-restored teeth between the intervention and control groups showed OHI-S and GI indices were lower in the intervention group and this difference was significant (P = 0.004), (P=0.003), however PPD in crowned teeth did not differ significantly between the two groups (P\u0026gt; 0.05). In the control group, GI and PPD increased significantly in crowned teeth, while plaque accumulation remained unchanged. In contrast, the CHX group showed no significant differences between crowned and control teeth.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eChlorhexidine mouthwash usage improved gingival health, and decreased plaque accumulation. Therefore, providing instructions about using mouthwash after placing SSCs especially in patients with poor oral hygiene is recommended.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration:\u003c/strong\u003e This trial was registered at the Iranian Registry of Clinical Trials (IRCT) on April 17, 2021, under registration number IRCT20210417050994N1.\u003c/p\u003e","manuscriptTitle":"The effect of chlorhexidine mouthwash on gingival health around stainless steel crowns in primary molars","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-21 06:49:55","doi":"10.21203/rs.3.rs-7058941/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-26T05:21:05+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-24T15:50:46+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-23T05:38:55+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-21T10:41:36+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-18T16:22:05+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-17T11:50:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"255404900247825539032547511443813594557","date":"2025-08-17T11:15:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"40262611378630645781299332994978045198","date":"2025-08-17T08:49:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"82690914463710473521479836641700493118","date":"2025-08-14T02:28:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"271346385660425887696584737485126230886","date":"2025-08-13T05:03:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"62762322174637475078995184789611432114","date":"2025-08-13T04:13:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"73606971315153779426233517121451094112","date":"2025-08-12T16:59:40+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-12T08:31:59+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-12T08:29:15+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-08-12T08:19:37+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-10T00:08:13+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Oral Health","date":"2025-08-10T00:05:45+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"513d57f1-631f-46a7-a345-32fd8c7119ca","owner":[],"postedDate":"August 21st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-05-04T16:10:28+00:00","versionOfRecord":{"articleIdentity":"rs-7058941","link":"https://doi.org/10.1186/s12903-026-07902-w","journal":{"identity":"bmc-oral-health","isVorOnly":false,"title":"BMC Oral Health"},"publishedOn":"2026-04-28 15:57:18","publishedOnDateReadable":"April 28th, 2026"},"versionCreatedAt":"2025-08-21 06:49:55","video":"","vorDoi":"10.1186/s12903-026-07902-w","vorDoiUrl":"https://doi.org/10.1186/s12903-026-07902-w","workflowStages":[]},"version":"v1","identity":"rs-7058941","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7058941","identity":"rs-7058941","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}