MICROBIAL ALTERATIONS IN SUPRAGINGIVAL DENTAL PLAQUE IN RESPONSE TO ATRICLOSAN-CONTAINING DENTIFRICE

A total of 325 subjects were entered into a double-blind, stratified 2 -treatment clinical study that examined the effects of a dentifrice co ntaining 0.3% triclosan, 2% Gantrez(R) copolymer and 0.243% sodium flu oride on supragingival dental plaque and gingivitis. A subset of 159 s ubjects including 72 men and 87 women participated in the microbiologi cal component of this study, which was designed to detect shifts in su pragingival bacterial species in response to triclosan. Subjects were divided into two groups: one performed normal oral hygiene with the tr iclosan/copolymer dentifrice and a control group used a placebo dentif rice without triclosan. At baseline, 3 and 6 months during treatment a nd at 6, 12, 18 and 24 weeks post-treatment, supragingival dental plaq ue was collected from the buccal and lingual surfaces of the 4 first m olar teeth and assayed for: 1) bacterial morphotypes by phase-contrast microscopy; 2) select bacterial groups and bacterial species by cultu re; and 3) target periodontal pathogens including Actinobacillus actin omycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis and Prevotella intermedia by immunofluorescence microscopy. There were few statistically significant differences between treatment groups in any of the 90 microbiological parameters measured at the 7 different lime points. The control group demonstrated significantly higher levels of cultivable Neisseria and higher proportions at the 3-month treatment period of P. gingivalis-infected subjects and mean cells. After 6 mont hs of treatment, the triclosan group demonstrated higher levels of fus iforms. Analysis of triclosan resistance data failed to detect a shift towards increased proportions of bacteria resistant to triclosan, and both treatment groups demonstrated triclosan-resistant strains, predo minantly Veillonella dispar. This study confirms the microbiological s afety of triclosan-containing dentifrices and suggests that continued use can be associated with beneficial alterations in the bacterial com position of supragingival dental plaque.