The Caries Management System: are preventive effects sustained postclinical trial?

OBJECTIVES To report, at two and 4 years post-trial, on the potential legacy of a 3-year randomized controlled clinical trial (RCT) of the Caries Management System (CMS) at private general dental practices. The CMS was designed to reduce caries risk and need for restorative care. METHODS Nineteen dental practices located in city, urban, and rural locations in both fluoridated and nonfluoridated communities participated in the RCT. Eight practices were lost to follow-up post-trial; however, baseline mean DMFT balance between CMS and control practices was maintained. At the control practices, caries management following usual practice continued to be delivered. The patient outcome measure was the cumulative increment in the DMFT index score, and the practice outcome measures included the practice-mean and practice-median increments of patient DMFT index scores. In covariable analysis (patient-level unit of analysis), as the patients were clustered by practices, mean DMFT increments were determined through multilevel modeling analysis. Practice-mean DMFT increments (practice-level unit of analysis) and practice-median DMFT increments (also practice level) were determined through general linear modeling analysis of covariance. In addition, a multiple variable logistic regression analysis of caries risk status was conducted. RESULTS The overall 4-year post-trial result (years 4-7) for CMS patients was a DMFT increment of 2.44 compared with 3.39 for control patients (P < 0.01), a difference equivalent to 28%. From the clinical trial baseline to the end of the post-trial follow-up period, the CMS and control increments were 6.13 and 8.66, respectively, a difference of 29% (P < 0.0001). Over the post-trial period, the CMS and control practice-mean DMFT increments were 2.16 and 3.10 (P = 0.055) and the respective increments from baseline to year 7 were 4.38 and 6.55 (P = 0.029), difference of 33%. The practice-median DMFT increments during the 4-year post-trial period for CMS and control practices were 1.25 and 2.36 (P = 0.039), and the respective increments during the period from baseline to year 7 were 2.87 and 5.36 (P < 0.01), difference of 47%. Minimally elevated odds of being high risk were associated with baseline DMFT (OR = 1.17). Patients attending the CMS practices had lower odds of being high risk than those attending control practices (OR = 0.23, 95% CI = 0.06, 0.88). CONCLUSION In practices where adherence to the CMS protocols was maintained during the 4-year post-trial follow-up period, patients continued to benefit from a reduced risk of caries and, therefore, experienced lower needs for restorative treatment.