Transition probabilities for dental caries in a school-based prevention program: A randomized clinical trial

Background: School-based caries prevention using silver diamine fluoride (SDF) has been shown to effectively prevent and control dental caries. To better inform program design and implementation, this paper estimated transition probabilities for dental caries in a school SDF program. Methods: The CariedAway project was a pragmatic, cluster-randomized trial of school-based caries prevention interventions conducted in predominately low-income minority children. For children in CariedAway receiving SDF, transition probabilities were computed between sound, carious, and arrested states for 6-year molars using multistate Markov models. Subject-level transition probabilities over one- and two-year periods were then calculated by aggregating states of all 6-year molars and first and second bicuspids. Results: A total of 7418 children were enrolled in CariedAway, of which 1352 met inclusion criteria for this study. Of eligible participants, the baseline prevalence of untreated decay was 29% and the prevalence of dental sealants was 8%. The probability of transitioning between sound and carious states in 6-year molars ranged from 0.0022 to 0.0074. At the subject-level, the sound to carious transition probabilities were 0.07 and 0.12 after one and two years, respectively. Once in a fully arrested state, the probability of remaining arrested was 0.72 and 0.60 after one and two years. Conclusions: The overall probabilities of teeth remaining in diseased-free or arrested states was high after receiving silver diamine fluoride, although multiple applications might be needed for consistent caries arrest.