Analysis of the Ability of DMSO (Dimethyl Sulfoxide) and Lidocaine to Penetrate Dentin

摘要

Commonly used topical anesthetics in dentistry lack the ability to penetrate beyond the outer layers of the oral mucosa and must be applied for relatively long periods of time in order to see an effect. This is unacceptable in a dental emergency. Dimethyl sulfoxide (DMSO) is an analgesic drug that is readily absorbed through the skin and mucous membranes and which can also increase the penetration of other drugs across biologic barriers. Our current research is to develop a fast acting topical analgesic compound using DMSO plus a topical anesthetic that could be applied to the dentin of a painful tooth. The Pashley tooth chamber was used to evaluate the ability of DMSO, lidocaine, and their combination to penetrate 9.5mm human dentin in vitro. Flow rates for DMSO through dentin were not directly proportional to the concentration of DMSO. Lidocaine HC1 more easily penetrated dentin than lidocaine base. DMSO has little effect on the penetration of lidocaine base but decreased the penetration of lidocaine HC1. A preliminary in vivo study in cats produced negative results. Keywords: Pain; Neurophysiology. (aw)