Weak Evidence Supports Antimicrobial Effect of Chlorhexidine Varnish in Patients with Fixed Orthodontic Appliances

Adnan Abdullah Al-Fahd, BDS, MS, PhD: Background This article critically appraises a systematic review conducted in 2015 that aimed to determine the antimicrobial efficacy of chlorhexidine varnishes (CHX-V) on mutans streptococci (MS) in patients undergoing orthodontic treatment with fixed appliances. Clinical question Does the application of CHX-V significantly decrease MS in patients undergoing orthodontic treatment with fixed appliances? Summary of methods An electronic systematic search up to September 2014 was conducted using Ovid MEDLINE, Scopus, and EMBASE. In addition, Google was searched for possible articles that met the inclusion criteria. Risk of bias was assessed independently by three reviewers. Critical appraisal This review met most requirements on the AMSTAR checklist. The overall quality of evidence was low as it included randomized and controlled studies as well as noncontrolled studies. Many confounding variables including CHX-V concentration, time of application, and frequency of application necessitate that the results be interpreted with caution. Practical implications The use of CHX-V to reduce the activity of cariogenic bacteria and caries incidence in patients with fixed orthodontic appliances may be beneficial despite weak evidence.