Effects of water, speed, and experimental instrumentation on finishing and polishing porcelain intra-orally

Previous studies indicated that porcelain can be polished smoother than glazed porcelain with instruments suitable for intra-oral use. This study evaluated several experimental instruments and materials to determine if polishing could be done more efficiently. Scanning electron microscopy was used to evaluate the surface texture produced by different combinations of experimental instruments applied with high and moderate speed, wet and dry, to porcelain disks. No sequence matched the polished standard. However, the optimum surface texture was obtained with diamond instruments (with progressively smaller particle sizes) used at a moderate speed with water, followed by a 30-fluted carbide bur at high speed and dry, then diamond polishing paste on a webbed rubber cup. In all polishing sequences tested, the best results were obtained with each individual instrument when diamond instruments were used at moderate speed wet, and when carbide instruments were used at high speed dry.