Relationship between oral pain and ethanol concentration in mouthrinses.

Previous reports have indicated that certain mouthrinses, even when used as directed can induce oral pain. In order to help determine the causal agent(s), various commercially available mouthrinses, as well as control solutions, were tested in a psychophysical study in which subjects rated categories of pain during and after mouthrinsing. More specifically, the studies tested the effects of ethanol concentration on induced pain. The results show that there is a direct relationship between ethanol content and the amount of induced pain. Furthermore, the amount of pain was found to increase with time of rinsing, and to slowly decrease after cessation of rinsing. Lastly, comparison of ethanol/water controls with a marketed product (Clear Choice) matched for ethanol content showed that, while ethanol was the key factor in mouthwash-induced oral pain, other presently unidentified agents can also add to the effect.