Commercial Mouth-Rinses Comparison to Critical pH of Enamel and Dentin

Objectives: This study measured the pH of commercially available mouth-rinses in relation to the critical pH of enamel (pH=5.5) and dentin (pH=6.5) to investigate whether they might have an impact on health oral pH levels. Furthermore, we investigated the relationship between pH and characteristics [AG1] (fluoride and whitening status) described in the products label.
Methods: All the over-the-counter mouth rinses (n=72 products) were purchased between February-March 2018 at major retail and drugs stores in the Chicagoland area. The pH of each product sample (15mL) was measured in triplicate with a calibrated pH meter (Orion Start A214, Thermo Fisher Scientific, Waltham, MA). Label information on the fluoride and whitening status were obtained and compared against pH. pH values were categorized in relation to the critical pH of enamel and dentin The mean pH value for each product was then compared via non-parametric statistical tests.
Results: The mean pH of all products tested was 4.9±1.37 (range 2.87-9.53). The majority of products with a pH below 5.5 were non-whitening (82%, n=41) and/or non-fluoridated (62%, n=31).
Conclusions: Our data show that most products tested had a pH below the critical pH of enamel and dentin.