Effect of a mouth rinse and a high-fluoride toothpaste on caries incidence in orthodontic patients: A randomized controlled trial.

INTRODUCTION: The objective was to evaluate the effect of a fluoride mouth rinse and a high-fluoride toothpaste on caries incidence in patients undergoing orthodontic treatment with fixed appliances. METHODS: In this 3-armed, parallel-group, randomized controlled trial, patients referred to the Specialist Clinic of Orthodontics, Mölndal, Sweden, were randomly allocated to 1 of the 3 groups. (1) Fluoride mouth rinse (FMR) group: 0.2 % sodium fluoride (NaF) mouth rinse plus 1450 ppm fluoride (F) toothpaste; (2) High-fluoride tootpaste (HFT) group: 5000 ppm F toothpaste; and (3) Control (CTR) group: 1450 ppm F toothpaste. The generation of a randomization sequence was performed in blocks of 30. Inclusion criteria included patients scheduled for treatment with fixed appliances in the maxillary and mandibular arch aged 12-20 years. The primary outcome variable was the change in Decayed Initial Filled Surfaces (ΔDiFS) based on radiographs taken before and after the treatment. For statistical comparisons between groups, the Kruskal-Wallis test were used for continuous variables, whereas the Mann-Whitney U-test was used for pairwise group comparisons. Furthermore, the risk ratio (RR) and 95% confidence interval (CI) based on clinically relevant cutoffs (DiFS ≥2) were calculated to compare the increase of caries during orthodontic treatment between 2 groups. The Cochran-Mantel-Haenszel method was used to adjust RR for baseline values. Blinding was employed during the caries registration and the data analysis. RESULTS: In total, 270 participants were randomized, with 15 patients dropping out, such that 255 patients were included in the statistical analyses. Recruitment was from October 2010 to December 2012. An increase in DiFS (≥1 DiFS) during treatment was observed in 48.3% of the FMR group, 42.0% of the HFT group, and 35.6% of the CTR group. There was no significant difference between the groups regarding increased DiFS (P = 0.17). The risk of increase in DiFS ≥2 during orthodontic treatment was 31.0% in the FMR group, 25.9% in the HFT group, and 18.4% in the CTR group. The RR for an increase of ≥2 DiFS during orthodontic treatment was 1.38 (95% CI, 0.81-2.34; P = 0.23) for FMR vs CTR, 1.21 (95% CI, 0.70-2.10; P = 0.51) for HFT vs CTR, and 0.93 (95% CI, 0.57-1.49; P = 0.76) for HFT vs FMR. CONCLUSIONS: In patients who demonstrate a low prevalence of caries and are undergoing orthodontic treatment, daily use of high-fluoride toothpaste or fluoride mouth rinse in combination with regular toothpaste does not appear to significantly alter the caries incidence compared with the use of regular toothpaste. TRIAL REGISTRATION: The trial was registered in the FoU i Sverige research database (http://www.fou.nu/is/sverige), with registration no. 236251. PROTOCOL: The protocol was not published before trial commencement. FUNDING: Local Research and Development Board for Gothenburg and South Bohuslän (grant no. 768531); and The Swedish Patent Revenue Fund (grant number EKF-780/19).