Here is a very well researched article on triphala. From the article “ Human clinical trials using Triphala water decoction as a mouthwash report that it exerts comparable efficacy compared with chlorhexidine gluconate germicidal mouthwash in the prevention of dental caries. For example, a study in human subjects revealed that Triphala (6%) mouthwash promoted a significant reduction in oral streptococcus colonies. Oral streptococcus levels were measured after using a 6% Triphala mouthwash or 0.2% chlorhexidine mouthwash twice per day for 48 h and for 7 days”