Prevention of Adult Caries Study (PACS)

The Prevention of Adult Caries Study (PACS) is a randomized, double-blind, placebo-controlled Phase III clinical trial conducted under F.D.A. Investigational New Drug license #45,466, with a target enrollment of 1000 at four clinical centers with vastly different populations. The centers participating in this proposed research are: Kaiser Permanente's Dental Plan in Portland, Oregon; Tufts University Dental Clinic in central Boston, Massachusetts; Delta Dental Massachusetts' Dental Clinic in Southborough, Massachusetts; and the dental clinic of the Tuba City Regional Health Care Corporation in Tuba City, Arizona. Kaiser Permanente's Center for Health Research in Portland, Oregon will act as the data-coordinating center, and Tufts University will act as the Administrative Center. This study is designed to evaluate the efficacy of a topical, temporary, 10% w/v chlorhexidine dental coating in reducing caries increment in at-risk adult dental patients. This study will treat participants in months 1(4 weekly applications) and 7(1 application) with final outcome measured at 13 months after randomization. Examiners were trained and certified before data collection started and were recalibrated annually. The primary outcome analysis in the intent -to- treat sample compares active to placebo group on the rank-normalized caries increment score, adjusting for examiner, age and age squared. Multiple imputation (data augmentation using MCMC) will be used to replace missing outcome. Planned secondary analysis examine the secondary caries increment outcomes using the same model, as well as parallel analyses in the per-protocol group. Safety of the coating will be evaluated by comparing development of resistant S. mutans or C. albicans as well as incidence of MedDRA-coded adverse events between the two arms.