There is an increasing demand for dental implant treatment. Currently, dental implant crowns are formed by cutting semi-sintered ceramics (composite functional ceramics material) and then sintering the ceramics at a high temperature. Hence, there are some concerns that the form accuracy of the workpiece cannot be maintained. Meanwhile, it is usually difficult to machine sintered ceramics with high precision and high efficiency. In this study, we investigated the basic grinding characteristics of dental ceramics due to lack of data on wheel wear, removal quantity, surface property, etc. The results showed that sintered ceramics can be ground with high precision and efficiency.

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Wet etching is often used as a micromachining method on substrates required to manufacture microreactors, etc, but this has problems related to both safety and the adverse environmental impact of waste etchant. Here, micropatterning on substrates using cavitation-aided abrasive machining, in which loose abrasive grains mixed in water interfere with the substrate surface and have an impact on cavitation generated in suction flow, is proposed and the machining effects and characteristics were investigated experimentally. Cavitation-aided machining with masks can make microchannels in the millimeter or submillimeter width range with a surface finish of several nanometers. In addition, several types of unique microprofile can be fabricated on substrates depending on the mask pattern used; for example, microterraced grooves and dimples.

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In dental treatment with Nd:YAG lasers, a quartz optical fiber is generally used to transmit the laser beam, which is used to irradiate the hard and soft tissue for caries treatment and periodontal tissue excision. As normal optical fiber has difficulty irradiating a narrow space and the inner root canal uniformly, it is effective to use a processed optical fiber tip that allows a diffuse and circumferential laser beam. Here, a new process to obtain these laser beams with titanium oxide powder is proposed, and the characteristics and performance of the processed optical fiber (TP fiber) are investigated. An experimental instrument was developed to measure the energy partition radiated from the TP fiber tip, and the ratio of a straight beam, a sideways beam, and heat generated by absorption of the laser beam were measured under various conditions. Moreover, the cavity on the dentin formed with the TP fiber was measured with a 3D surface profiling system.

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