A 17 Year Survey of Triclosan Efficacy on Supragingival Plaque

Dentifrices and other oral hygiene preparations maybe formulated with triclosan (TCN), a broad-spectrum antimicrobial agent. In clinical studies, subjects using TCN dentifrice demonstrate improved oral health due to significant reductions in plaque and gingivitis. Objectives: This study examined the antimicrobial efficacy of TCN on human supragingival plaque over 17 years. Materials and Methods: Adults who had not received dental treatment or systemic antimicrobial therapy for the previous 30 days were included. Data obtained from 105 adults over 12 separate study periods are presented in this report. Supragingival plaque was collected from the entire dentition and aliquots of the bacterial suspension were distributed onto solid media containing 0, 7.5 or 25 µg/ml TCN. Following incubation at 37oC for 5-7 days, the number of colony forming units (CFU's) was enumerated. Results: All subjects demonstrated large numbers of CFU's on media without triclosan. By contrast, supragingival plaque bacteria were substantially inhibited by TCN (p<0.001). Inhibition with 7.5 and 25 µg/ml TCN ranged from 97.3-100% and 99.6-100%, respectively. For each TCN concentration, ANOVA was used to compare the percent susceptible bacteria between each study period. Over the 17-year duration, no differences in microbial susceptibilities were observed between each period for either concentration of TCN (p>0.28). Regression analyses for each TCN concentration indicated no alterations or trends in efficacy (p values of 0.208 and 0.71 for the 7.5 and 25 µg/ml TCN, respectively) over time. Conclusions: The data demonstrates the significant efficacy of triclosan on supragingival plaque bacteria over a 17-year period with no change in antimicrobial susceptibility. Since study participants were not selected based on the use of any oral hygiene formulation, the results indicate that triclosan is efficacious on supragingival dental plaque from a variety of subjects. These results demonstrate that triclosan represents a safe and effective agent for dental plaque bacteria.