Clinical and PCR Evaluation of Antiplaque Effect of Two Dentifrices

Objective: to evaluate the antiplaque efficacy of two commercial dentifrices, one contains 0.3% triclosan/1100 ppm NaF (product A) and another contains 0.45%SnF2 and zinc lactate (product B), via clinical and PCR methods. Method: Twenty five healthy human subjects participated in the crossover, double-blinded, randomized study. Clinical results were measured by the Gingival Margin Plaque Index (MGMPI), and PCR analysis was carried out by the SYBR® green real-time PCR via amplification of the 16S rRNA gene. After 1-week washout using a regular fluoride toothpaste, subjects were instructed to return to the dental clinic in the morning for clinical score and dental plaque collection. Baseline plaque was collected prior to brushing with a test product for PCR. Baseline clinical plaque score was determined after brushing. No oral hygiene was permitted for 24 hours. Then subjects donated 24-hr post-brushing dental plaque and immediately received a second clinical plaque score. The difference between two time points (0 and 24 hr) was calculated. For PCR analysis, total bacterial DNA counts-using universal primers- and levels of pathogens -using specific primers-, were determined. Percentage reduction of total bacterial DNA and specific organisms DNA was calculated. Results: The average MGMPI score was 12.95±7.18 for product A and 25.35±10.08 for product B (p<0.05). The percentage reduction of total bacterial DNA versus baseline was 24.78% for product A and 8.31% for product B (p<0.05). Product A reduced more representative oral bacteria, eg. S. mutans, L. casei, P. melaninogenica, and T. forsythensis DNA when compared to Product B. Conclusion: Product A, containing 0.3% triclosan/1100 ppm NaF, provides clinical superiority on plaque control than product B, containing 0.45% SnF2 and zinc lactate. In addition, PCR results demonstrated superior antibacterial efficacy of product A over product B.