Newly developed dental composite resins including various ceramic fillers have been developed for use in crown restoration. The polishing procedure for dental composite resin is very difficult, because ceramics fillers have relatively high hardness. Therefore, a multistep process for touch-up using several polishing tools is performed to achieve a smooth surface on the composites with current polishing technology. Dentists and dental technicians require means of decreasing the number of steps in polishing. A high-performance polishing tool provides an opportunity to bypass some of the steps in the polishing process. However, their polishing specifications are still not fully understood. In this study, a sodium alginate bonded mounted silicon carbide wheel was developed for dry polishing of dental composite resin. Using this mounted wheel, dry polishing of commercially available dental composite resin was achieved in a shorter time compared with three commercial mounted wheels designed for use by dentists and dental technicians. In addition, the surface roughness of the polished surface became smaller and the surface integrity was superior in quality.

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In the hole drilling process, chips remaining inside the drilled hole can easily adhere to the tool. To prevent chip adhesion, an electroplated diamond tool with a hemispherical edge and two plain clearances for discharging cutting chips at the cylindrical part has been developed. Using this tool, chip adhesion on the tool can be reduced as the cutting chips are efficiently discharged during the hole drilling process. However, as the number of drilling process increases, a small amount of remaining cutting chips begin to adhere to the chip discharge area, which influences the chip discharge performance. This study was performed to investigate the properties of surfactant contained in machining fluid used in the hole drilling process and their influence on chip adhesion.

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