The antimicrobial effect of chlorhexidine varnish on mutans streptococci in patients with fixed orthodontic appliances: a systematic review of clinical efficacy

Objective: To conduct a systematic review aimed to determine the antimicrobial efficacy of chlorhexidine varnishes (CHX-V) on mutans streptococci (MS) in patients during orthodontic treatment with fixed appliances. Materials and Methods: A systematic computerized database search was conducted using Ovid MEDLINE, Scopus and EMBASE up to September 2014. A Google search was also conducted to further identify articles that met the eligibility criteria. Clinical trials which used CHX-V alone as the intervention to investigate the antimicrobial effect of the varnish in subjects undergoing orthodontic treatment were included. Outcome measures included MS level reduction and/or decreased caries incidence from baseline data. Results: Nineteen articles were identified for full-text reading; eleven articles met the criteria for inclusion in this review. Type and concentration of CHX-V, bacterial sampling method, application frequency, sampling schedule, risk of bias and study outcomes are presented. Conclusion: A limited number of studies with low risk of bias were available to address the antimicrobial efficacy of CHX-V on MS in patients during orthodontic treatment with fixed appliances. Therefore, while the majority of studies found CHX-V to be an effective antimicrobial against MS at an interval of 3-4 weeks, the strength of the recommendation is weak. Longitudinal studies are needed to determine whether this antimicrobial effect will contribute to clinically significant caries reduction in patients undergoing orthodontic treatment with fixed appliances.