Demineralisation following orthodontic treatment: Recruitment to an RCT

Objectives: To determine the incidence of and factors affecting demineralisation in patients completing fixed orthodontic treatment who were willing to participate in a randomised clinical trial (RCT) to assess the remineralising potential of toothpastes containing different concentrations of fluoride. Methods: Patients completing fixed orthodontic treatment with upper and lower fixed appliances were invited to participate in the RCT. Those willing to participate were screened for the presence of demineralisation (white spots) using quantitative light fluorescence (QLF). Patients with white spots were eligible to participate and randomised into one of three toothpaste groups. Results: 250 patients completing orthodontic treatment were screened for eligibility. 69 (27.6%) had no white spots and were ineligible for the trial. 171 (68.4%) had 1-12 white spots and 10 (4.0%) were not suitable. The median number of white spots, of patients with spots, was 4 (IQR 3, 6). 42 participants (24.5%) had 1 or 2 spots (low level of demineralisation); 94 (55.0%) 3-6 spots (medium) and 35 (20.5%) had 7-12 spots (high). Patients with white spots were statistically significantly younger (mean difference 2.8 years; 95% confidence intervals 1.17, 4.42) than those without. There was no statistically significant difference in the incidence of white spots between male and female patients (Chi-square = 7.1; df = 9; p = 0.62). Conclusions: Over two thirds of patients, completing fixed orthodontic treatment with upper and lower fixed appliances who were willing to participate in an RCT, had evidence of demineralisation with a median of 4 white spots (IQR 3, 6). Patients with white spots were significantly younger than those without spots but there was no difference in the presence of spots or severity of demineralisation between males and females.