New Caries Prevention Metric: Cumulative Proportion of Sound Teeth (cPrST)

Objectives: To develop a new index to measure the effectiveness of caries prevention programs, the cumulative Proportion of Sound Teeth (cPrST), and to evaluate this index in a school-based setting.
Methods: The cPrST is the number of sound teeth per child at a given visit divided by the number of sound teeth at baseline. The cPrST ranges from 0-100%. We used two different denominators to calculate the cPrST: observed sound teeth in primary dentition, or teeth at current or future risk in primary and permanent dentations, separately. We analyzed data from ForsythKids, a school-based caries prevention program serving Title 1 elementary schools in greater Boston. All students in participating schools were eligible for ForsythKids, which provides access to comprehensive preventive services, including fluoride application, sealants, and referrals for active dental disease. All patients seen from 2004-2010 were eligible for inclusion in data analysis. We estimated the average reduction in cPrST over 5 post-baseline visits, and 95% confidence intervals (95%CI).
Results: The total number of children was 6,927 in 33 schools. Fifty-five percent had treated or untreated caries at their initial visit. The average reduction in cPrST in the primary dentation was 3.7 percentage points (points) per visit (95%CI: 3.8 points, 3.6 points) using observed teeth at baseline and 2.0 points (95%CI: 2.1 points, 2.0 points) using teeth at current or future risk. There was a 1.6-point reduction in cPrST per visit (95%CI: 1.6 points, 1.5 points) in permanent teeth.
Conclusions: The goal of preventive programs is to maintain healthy teeth as long as possible. In contrast to the current metrics for evaluating preventive dental programs, which focus on disease risk, prevalence, or intensity, the cPrST focuses on the maintenance of health, i.e. sound teeth. The cPrST could be a valuable tool for evaluating the effectiveness of caries prevention programs or modalities.