Management of white spot enamel lesions with resin infiltration: potentials and future research directions.

Design: The current study is a randomized controlled trial with two arm, multicenter and parallel group design.

Case Selection: Study subjects were 38 orthodontic patients younger than 17 years who were being treated with metal braces. Patients with at least one white spot lesion (WSL) graded 1 to 2 according to the International Caries Detection and Assessment System (ICDAS) on the labial surface of permanent maxillary and mandibular canines and incisors were included for the trial. Teeth with carious lesions and restorations, anomalies of the enamel, and primary teeth were excluded.

Method: Patients were allocated by computer generated random sequence into resin infiltration and fluoride varnish intervention groups. Study subjects were blinded until the allocation, outcome assessors and statisticians remained blinded through the study, however the operators could not be blinded. Resin infiltration treatment involved removal of orthodontic wires and auxiliaries followed by cleaning the teeth with fluoride free prophylactic paste and completing the resin infiltration according to manufacturer's instructions. In the fluoride varnish group, a thin layer of the material was applied after isolating the teeth, and patients were asked not to eat or drink for 1 hour. This was continued twice a month for 6 months. Digital images of the teeth were obtained before, and 1 day (T1), 1 week (T2), 1 month (T3), 3 months (T4) and 6 months (T5) after treatment, using a DSLR camera and a matching polarization filter. The images were processed for calibration and color stability. Regions of interest representing WSL (white spot lesion) and SAE (sound adjacent enamel) were isolated in the images for comparison at different stages the images were captured.

Data Analysis: Statistical analysis was performed using SPSS version 28. Independent-samples t-test was utilized for comparison between the two groups, and paired-samples t-test for comparison within the groups. A statistical significance level of α = 0.05 was set.

Results: At T1, significant color difference was observed between white spot lesion and adjacent sound enamel in the resin infiltration group and it remained stable after 6 months. Whereas in the fluoride varnish group, there were no statistical differences from baseline to 6 months. A statistical difference of 3.27 CIELAB units (p < 0.001) was reported between the infiltration group and the fluoride group at T5. No significant changes were noted in SAE with respect to changes in lightness.

Conclusions: Resin infiltration was found to be better at masking the demineralization produced by WSL and also enhanced the esthetic appearance of demineralized areas around the brackets. Resin infiltration did not produce any clinically visible effects in non-affected enamel. These changes remained stable for a period of 6 months.