Long-term motivational effects of an RCT of supervised toothbrushing

Objectives: The aim of this study is to investigate whether the prolonged dental health benefits found several years after the cessation of a randomised controlled trial of supervised toothbrushing is due to a change in toothbrushing behaviour, by examining the caries prevalence on teeth which erupted after the end of the intervention period. Methods: 461 children aged 5 years in 12 schools in Tayside, Scotland completed a randomised controlled trial of supervised toothbrushing with a fluoride toothpaste at school, combined with a home support package. The intervention lasted 30 months, and children were followed up regularly up to 6.5 years after the completion of the intervention. All examinations were conducted by a single examiner. In addition to the dental caries examination, at each visit, oral cleanliness was assessed by a visual plaque index measured on 6 surfaces. Results: In the examination at age 14, 25% of the children who had been in the intervention group had caries into dentine on teeth which had erupted after the end of the intervention (canines, premolars or second molars). In the non-intervention group, 35% had dentinal caries on these teeth. Logistic regression analysis with this caries variable as the outcome identified presence of plaque at age 14 (p=0.001), presence of plaque at the baseline examination (p=0.006), and intervention group (p=0.030) as significant variables. The odds ratio for the effect of intervention group was 1.78. Conclusion: The significant association between intervention group and the development of caries into dentine on teeth erupting after the end of the intervention may provide evidence that the reduction in caries is due to a long-term effect of the intervention on toothbrushing habits.