The article: The role of chlorhexidine in caries prevention.
The journal: Oper Dent. 2008 Nov-Dec;33(6):710-6.
The author: Autio-Gold J.
Why we should we know it: Many preventive experts recommend having patients use chlorhexidine rinse intermittently on high caries risk patients to reduce the oral bacterial load.
What we need to know: This study reviews and summarizes the current literature on the use of chlorhexidine to reduce caries. The idea is that chlorhexidine's antimicrobial properties will reduce the amount of strep mutans which will reduce the amount of cariogenic acid produced. From a "common sense" point of view, this should be a no brainer. However, the data does not support this. The available data shows that chlorhexidine rinses do reduce gingigival inflammation, the data does not show any reduciton in amount of caries. Chlorhexidine gels and varnishes which are not available in the US were also studied. Results were inconclusive on these materials so the authors suggested more studies be done. To summarize in one line, the authors claim that the data does not show that chlorhexidine rinse reduces caries and because of it's side effects, should not be used for that reason alone.