Evaluation of the preventive effect of two concentrations of xylitol varnish versus fluoride varnish on enamel demineralization around orthodontic brackets: a randomized controlled trial

Background: The highly prevalent white spot lesions around orthodontic brackets necessitate introducing preventive materials without relying on patient compliance. Objective: To evaluate the antidemineralizing effect of two concentrations of xylitol varnish. Trial design Triple-blind, four-arm, parallel-group, single-center, randomized controlled clinical trial. Methods: A total of 120 orthodontic patients were randomly assigned to four groups (n = 30), using a computer-generated randomized block list. The treatment groups were: 10% xylitol, 20% xylitol, 5% fluoride, and placebo. Tooth demineralization was measured with DIAGNOdent at T-1 (before treatment), followed by varnish application. At T-2 (third month), the varnish was re-applied, and at the third (T-2) and sixth (T-3) months, and after treatment (T-4), the demineralization was measured. The white spot lesion frequency was assessed visually after treatment. The participants, the clinician, and data assessors were all blinded to group assignments. Results: A total of 115 patients underwent per-protocol analyses. At T-2, the mean DIAGNOdent numbers in the fluoride and 10% xylitol groups were significantly lower than the placebo group (P = 0.00), with a mean difference of 0.63 (95% CI, 0.15-1.10) and 0.5 (95% CI, 0.04-0.95), respectively. At T-3, the fluoride and 10% xylitol groups had significantly lower mineral loss than the placebo group (P=0.046) with a mean difference of 0.52 (95% CI, 0.14-0.89) in the fluoride and 0.45 (95% CI, 0.03-0.86) in the 10% xylitol groups, respectively. However, at T-4, only the mean for the 10% xylitol group was significantly different (P=0.049) from the placebo group, with a mean difference of 1.18 (95% CI, 0.42-1.93). Visual assessment showed that after treatment, the prevalence of white spot lesions in the fluoride (P=0.03) and 10% xylitol (P=0.00) groups was less than the placebo group with the odds ratio of 0.67 (95% CI, 0.46-0.96) and 0.43 (95% CI, 0.28-0.64), respectively. Conclusion: The 10% xylitol varnish short-term effects on caries control were significantly greater than 20% xylitol varnish and placebo but similar to fluoride varnish. However, the 10% xylitol long-term effect was almost better than fluoride varnish.