Comparative assessment of four treatments for post orthodontic white spot lesions over a 24-month period: a randomized controlled clinical trial

OBJECTIVES: The aim of this study was to evaluate and compare the effects of resin infiltration (RI), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), fluoride varnish (FV), and fluoride toothpaste on white spot lesions (WSLs) over a 24-month period. MATERIALS AND METHODS: This study was a 24-month prospective, randomized, double-blind, multicenter clinical trial. Stratified randomization by center was employed, and patients were randomized using allocation sequences, with allocation concealment achieved via sequentially numbered, opaque, sealed envelopes. Seventy-nine participants who had finished orthodontic treatment were randomly assigned to be treated with RI, CPP-ACP, FV or fluoride toothpaste and were recalled every 6 months. The subjects in the RI group who received the RI treatment at baseline and had their teeth coated with fluoride toothpaste every six months starting from the second visit. In addition, all the participants used the provided fluoride toothpaste to brush their teeth twice daily for routine oral hygiene. The DMFT index was recorded at baseline and at each visit. Intraoral images were captured, and the changes in the WSLs area were assessed by ImageJ software. RESULTS: In this study, we enrolled 20 participants in the FV group, CPP-ACP group, and RI group and 19 participants in the fluoride toothpaste group. Ultimately, 14, 17, 12, and 14 participants in each group completed the final follow-up, respectively. After 24 months, there were no significant differences in the mean DMFT index between the groups. All four treatments effectively reduced the WSLs over time. After 24 months, the rate of change in WSLs area in the RI group (-56.66 ± 20.70, 95%CI: -62.23, -51.09) was significantly lower than those in the FV group (-42.01 ± 18.12, 95%CI: -46.28, -37.75), the CPP-ACP group (-45.27 ± 18.13, 95%CI: -49.83, -40.70) and the fluoride toothpaste group (-35.19 ± 25.79, 95%CI: -40.99, -29.38). Besides, the rate of change in WSLs in the CPP-ACP group was significantly lower than that in the fluoride toothpaste group. CONCLUSIONS: During the 24-month period, the combined use of RI, FV, CPP-ACP with fluoride toothpaste and fluoride toothpaste alone were effective in treating WSLs. RI management achieved the best and most stable effect in terms of reducing WSLs after 24 months. In addition, after 24 months, CPP-ACP management was better than fluoride toothpaste management alone for reducing WSLs. REGISTRY: Chinese Clinical Trials Register, TRN: ChiCTR2000032516, Registration date: 1 May 2020.