LAUSR

Background Removable orthodontic appliances due to plaque accumulation and oral microbe colonization, might be associated with intraoral adverse effects on enamel or periodontal tissues. The present systematic review was carried out to evaluate both qualitatively and quantitatively the microbiological changes occurring during orthodontic therapy with removable orthodontic appliances. Methods PubMed, Cochrane, EMBASE, Web of Science, Scopus, Ovid Medline, Dentistry & Oral Sciences Source and Vita-Salute San Raffaele University databases were searched. The research included every article published up to December 2018. The Preferred Reporting Items for Reporting Systematic reviews and Meta Analyses (PRISMA) protocol and the ‘Swedish Council on Technology Assessment in Health Care Criteria for Grading Assessed Studies’ (SBU) method were adopted to conduct this systematic review. Results The current study has moderate/high evidence, according with SBU method. It demonstrates that removable appliances do influence the oral microbiota, with significant alterations just 15 days after the beginning of therapy, independently from the type of appliance. Furthermore, the levels of oral pathogens decrease significantly or even returned to pre-treatment levels several months later the therapy end. Conclusions This review suggests that orthodontic treatment with removable appliances might not induce permanent changes to oral microflora. Protocol: PROSPERO database registration number CRD42019121762.