Construction and evaluation of an inexpensive device that simulates oral clearance.

The clearance pattern of a specific substance is very important to estimate its oral availability. Devices or models that simulate clearance in the mouth are important to study the effects and retention time of foods and drugs. This report describes an efficient device which was assembled with low-cost materials in our laboratory and that can be used to study the clearance of cariogenic substrates, mouthwashes, programmed-release drugs as well as adsorption of drugs to enamel. The device can have up to three chambers with varying minimum and maximum volumes that can be eluted simultaneously at different flows. The simulated swallowed volumes are adjustable and the ratio between the maximum and minimum volumes can be programmed. We also present the results of an evaluation study using the device to determine the clearance of fluoride from a fluoride-containing mouthwash, the clearance of a 1% glucose solution and the programmed release of fluoride from a methacrylate bioadhesive using artificial saliva as eluent.