Selective caries removal with air abrasion.

The purpose of this study was to evaluate selective caries removal using an air-abrasive technique. Alumina powders, glass beads, crushed glass powders, and crushed powders of polycarbonate resin were applied to intact human enamel, dentin, and artificially demineralized dentin (caries-model dentin). Furthermore, the effect of the particle size of abrasives and air pressures on the abraded depths was examined. When alumina powders and glass beads were used, the abraded depths of enamel, dentin, and caries model increased as the particle size and air pressure increased. Alumina powders and crushed glass powders abraded intact enamel and dentin more than the caries-model dentin, whereas glass beads abraded the caries-model dentin more than the intact enamel and dentin. Only crushed powders of polycarbonate resin abraded the caries-model dentin without reducing intact enamel and dentin. With hard particles, such as alumina powders, glass beads, or crushed glass powders, selective caries removal by the air-abrasive technique appeared to be difficult to achieve, even if the particle size and the air pressure were changed. Crushed powders of polycarbonate resin that reduced only the caries-model dentin are harder than caries-model dentin, but softer than intact enamel and dentin. This study elucidated the possibility of selective carious dentin removal with the air-abrasive technique.