Rapid Method to Assess Effect of Dentifrice on Bacterial Metabolism

Objective: Previous studies have shown that the reduction in pH resulting from carbohydrate metabolism may lead to an increase in the proportion of acidogenic and aciduric bacteria in plaque biofilms which has been associated with caries. Dentifrices containing Triclosan and fluoride are known to posses both direct antimicrobial and inhibitory effects on oral bacteria and are additionally known to indirectly affect the oral bacterial population by reducing environmental acidification thus preventing the enrichment of acid tolerant species. This ex-vivo study measured the ability of a dentifrice containing Triclosan, pyrophosphate and fluoride (BAM Complete 7) to affect the pH response of salivary bacteria at 30, 60 and 90 minutes post brushing compared to brushing with water only. Method: In this two treatment cross-over study, 20 volunteers brushed with Crest Decay Prevention toothpaste during the two week test period. On Days 7 and 12, subjects provided pre-brush saliva samples and then brushed with either BAM Complete 7 or water. The subjects refrained from eating and drinking for the following 90 mins and provided saliva samples at 30, 60 and 90 minutes. The saliva samples were incubated with 5% glucose for 2 hours and the change in pH was calculated. The changes in pH post-treatment were compared by Analysis of Covariance, with the pre-brush sample pH change as the covariate. Results: A significantly smaller change in pH was observed after brushing with the dentifrice containing Triclosan, pyrophosphate and fluoride at all the time points studied (Overall: BAM Complete 7 pH = 0.818, Control pH = 1.164, Difference = 0.346 ± 0.11, p=0.0032). Conclusion: The results demonstrate a reduction in pH by salivary bacterial communities up to 90 minutes after brushing with the dentifrice containing Triclosan. Thus suggests a possible role of the dentifrice in preventing deleterious changes in oral bacterial population.