Caries Prevention in Patients Undergoing Orthodontic Treatment

Abstract: Background: Scientifically based guidelines to predict and prevent caries during orthodontic treatment with fixed orthodontic appliances are lacking. Aim: The overall aim of this thesis was to improve caries risk assessment before orthodontic treatment, as well as to evaluate caries risk and improve caries prevention during treatment. Patients and methods: Patients (n=270) undergoing treatment with fixed appliance at the Specialist Clinic of Orthodontics in Mölndal, Sweden, were included. Studies I, III and IV were performed with an RCT design, with the subjects being randomly assigned to one of the following groups: i. Fluoride mouth rinse (FMR) group, 0.2 % sodium fluoride (NaF) mouth rinse plus 1450 ppm F toothpaste; ii. High-fluoride toothpaste (HFT) group, 5000 ppm F; and iii. Control (CTR) group, 1450 ppm F toothpaste. In study I, the effect of orthodontic treatment and the different fluoride regimens on caries risk and caries risk factors were evaluated. Study II was performed with a prospective design that evaluated the CRA programmes and the caries indices abilities to predict the outcome of caries during treatment. In studies III and IV, the impacts of the different fluoride regimens on caries incidence (through radiographs and clinical photographs) during orthodontic treatment were evaluated. Results: The FMR and HFT groups showed an unchanged caries risk during treatment, while the caries risk increased significantly in the CTR group (p<0.0001). The DiFS index demonstrated the highest accuracy in predicting initial and manifest caries during treatment with fixed appliances, as compared to the multi-factorial CRA programmes. Radiographic analyses revealed no significant difference between the fluoride groups in terms of increased caries incidence during treatment. However, the numbers of patients with an increase of one or more white spot lesions (WSL) during orthodontic treatment were significantly higher in the CTR group than in the FMR group (p=0.0097) or HFT group (p=0.018) when the data for incisors, lateral incisors and canines were included. Conclusion: The DiFS index most-accurately predicts caries during orthodontic treatment. Furthermore, a mouth rinse or high-fluoride toothpaste can be recommended during orthodontic treatment to retain low caries risk and to reduce the numbers of WSLs in the aesthetic front.