Study warns popular type of mouthwash may be putting teeth at risk

Using a common type of mouthwash may be increasing your risk of developing tooth damage, according to a new study out of the University of Plymouth. The reason isn't directly due to the effects of the mouthwash on the teeth, but rather the ways it changes the profile of beneficial bacteria in one's mouth. Over time, a drop in saliva pH levels may increase the risk of damaged teeth.

We most commonly hear about beneficial bacteria in relation to the gut microbiome, but similar beneficial species are also found in the mouth. Past studies have found that dental hygiene practices can have both beneficial and risky effects on one's wider health, including helping protect against dementia but increasing the risk of high blood pressure.

According to the new study, mouthwash may negatively impact certain bacteria in the mouth, enabling bacteria that produce lactate to increase in number. This, in turn, may cause one's saliva to become more acidic, and the greater acidity may then damage teeth over time.

The findings were based on the use of chlorhexidine mouthwash for seven days, the results of which were compared to the use of a placebo mouthwash during the same time. Whether the decrease in oral microbial diversity is an overall disease risk is yet to be determined, according to the researchers.

This is the same mouthwash linked to oral bacterial changes that may lead to the development of high blood pressure. Chlorhexidine mouthwash is available in both over-the-counter and prescription varieties and may be used by dentists as a germicide before certain procedures. The findings indicate that regularly using this type of mouthwash in daily life may have unwanted negative consequences.