Plaque regrowth effects of a triclosan/pyrophosphate dentifrice in a 4-day non-brushing model

Triclosan is a lipophilic antimicrobial agent which, when present in an aqueous dentifrice vehicle, is complexed by or in close contact with polymers and surface-active molecules, emulsifying agents, flavoring oils and other hydrophobic ingredients. Because of this, dentifrice products containing triclosan may not have triclosan in a bioavailable state and, hence, the products themselves can not be assumed to possess antimicrobial activity. In order to determine the antimicrobial effects on dental plaque of a triclosan/pyrophosphate dentifrice relative to a negative control (without triclosan or pyrophosphate), a crossover 4-day non-brushing study was conducted. Thirty-four subjects were enrolled in this randomized two-period, double-blind crossover investigation with thirty-three subjects completing all aspects. Following a baseline plaque examination and complete plaque removal at the start of the first 4-day treatment period, subjects initiated a twice-daily supervised dosing regimen, during which they rinsed with their first assigned dentifrice in slurry form while refraining from tooth-brushing and all other oral hygiene procedures. Evaluations to quantify test product effects on plaque were conducted on Day 5. After a week-long interim washout period, subjects repeated the twice daily rinsing regimen over Days 1-4 of Treatment Period 2 with their second assigned product, again with examinations on Day 5. Analysis of data demonstrated subjects had significantly (p = 0.0296) less plaque when rinsing with the triclosan/pyrophosphate dentifrice slurry as compared to the negative control dentifrice slurry; the relative treatment difference as determined by the primary examiner was 12.7%. A trainee examiner observed a 16.0% reduction on a subset of subjects (p = 0.0139). This efficacy result compares favorably with results from other studies of triclosan-containing products. The examinations for oral safety demonstrated no meaningful clinical differences between the triclosan/pyrophosphate dentifrice and control dentifrice.