Changes in white spot lesions following post-orthodontic weekly application of 1.25 per cent fluoride gel over 6 months-a randomized placebo-controlled clinical trial. Part I: photographic data evaluation.

Abstract

White spot lesions (WSLs) are a frequent side-effect of multibracket appliance treatment. The effect of local fluoridation on post-orthodontic WSL is however inconclusive. Assessment of WSL changes in response to weekly 1.25 per cent fluoride gel application after multibracket appliance treatment. Randomized, single-centre, double-blind, parallel-group, placebo-controlled study. Patients with not less than 1 WSL (modified score 1 or 2) on not less than 1 upper front teeth after debonding. Professional fluoride/placebo gel application during weeks 1-2; self-administered home application (weeks 3-24). Photographic WSL assessment (dimension and luminance) of the upper front teeth (T0-T5). Random assignment to test (n = 23) or placebo group (n = 23) using a sequentially numbered list (random allocation sequence generated for 50 subjects in 25 blocks of 2 subjects each). The clinical study duration lasted from March 2011 to September 2013. Unblinding was performed after complete data evaluation. Intent-to-treat analysis set comprising 39 participants (test: n = 21, placebo: n = 18). Dimensional WSL quantification showed limited reliability. Luminance improvement (%) of WSL, however, was seen after 6 months (test/placebo: tooth 12, 24.8/18.0; tooth 11, 38.4/35.4; tooth 21, 39.6/38.3; and tooth 22, 15.2/25.0). No statistically significant group difference existed. Data suggest that WSLs are difficult to measure with respect to reliability and repeatability and methods for monitoring WSLs in clinical trials require improvement/validation. Similar adverse events occurred in both groups; none was classified as possibly related to the study product. The number of dropouts was higher than expected and the socio-economic status was not assessed. Furthermore, the unknown level of compliance during the home application phase must be considered as limitation. Based on the results of this study, no difference could be detected with respect to the development of WSL under post-orthodontic high-dose fluoride treatment. The study was registered with ClinicalTrials.gov (Identifier: NCT01329731). The protocol wasn't published before trial commencement.