Effect of bonded and removable retainers on occlusal settling after orthodontic treatment: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to summarize the effectiveness of bonded and removable retainers (the Hawley and Essix retainers) in terms of improving occlusal settling (occlusal contact points/areas) after orthodontic treatment. We searched the Cochrane Library, PubMed, CINAHL Plus, and Dental & Oral Sciences Source (DOSS), as well as SIGLE, Google Scholar and ClinicalTrials.gov for eligible studies. We included randomized and non-randomized controlled trials along with cohort studies. Studies that reported occlusal contacts/areas during retention with fixed bonded and removable retainers were included. To assess the quality of the randomized controlled trials (RCTs), the Cochrane Collaboration risk-of-bias (RoB) tool was utilized, whereas the Newcastle-Ottawa Scale (NOS) was used to assess the quality of cohort studies.We included 6 articles in our systematic review after scrutinizing 219 articles and eliminating the illegible ones based on duplication, titles, abstracts, and objectives. Bonded retainers (BRs) allowed faster and better posterior occlusal settling as compared to the Hawley retainer (HR). However, HR showed good occlusal settling in the anterior dental arch. The Essix retainer (ER) showed a decrease in occlusal contact during the retention phase. Meta-analysis showed no statistically significant difference between BRs and removable retainers. In conclusion, HR allowed better overall occlusal settling as compared to other retainers. However, BRs allowed faster settling in the posterior tooth region. The Essix retainer showed poor settling of occlusion. Overall, there is an insufficient number of high-quality RCTs to provide additional evidence, and further high-quality RCTs are needed.

Effectiveness of antimicrobial gels on gingivitis during fixed orthodontic treatment: A systematic review and meta-analysis.

OBJECTIVE: The present study was aimed to assess the effectiveness of antimicrobial gels along with conventional tooth brushing to improve gingival health in patients undergoing fixed orthodontic treatment. MATERIALS AND METHODS: All randomized and non-randomized clinical trials done on human subjects were explored in major health science databases (PubMed, CINAHL Plus, EBSCO Dent & Oral Sciences and Cochrane). An additional manual search was done on Google Scholar and on www.clinicaltrials.gov to identify any grey literature and unpublished data. Date of publication was not restricted during the data search. The assessment of risk of bias was done using the Cochrane Collaboration's Risk of Bias assessment tool. The meta-analysis was done using Review Manager Version 5.3.5 to analyse probing depth to be in two and four-week follow-up. This systematic review is reported according to the PRISMA statement and registered at PROSPERO (CRD42018084530). RESULTS: The electronic database search yielded 3733 records; hand search identified 14 articles meeting the selection criteria which were included in the qualitative data synthesis. Significant improvement in gingivitis has been reported using antioxidant-essential oil gel, cervitec gel (0.2% chlorhexidine), 2% chlorhexidine gel, amine fluoride gel, and 0.4% stannous fluoride gel with>98% availability of Sn+2 ions. Three articles with probing depth as comparable parameter were used for quantitative analysis. At the two and four-week follow-up, overall insignificant differences were observed in the antimicrobial gel group compared to the control group with regard to probing depth. CONCLUSIONS: The use of antioxidant-essential oil gel, amine fluoride gel, 0.4% stannous fluoride gel (98% availability of Sn+2) and 2% chlorhexidine gel resulted in significant improvement in gingivitis. However, probing depth in follow-up visits showed no significant difference between antimicrobial gel and control group.