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Dental caries and periodontal disease are two major diseases in the dentistry. As the society is aging, their pathological meaning has been changing. An increasing number of patients are displaying symptoms of systemic disease and so we need to pay more attention to immunologic aggression in our medical treatment. For this reason, we focused on natural products. Kampo consists of natural herbs—roots and barks—and has more than 3000 years of history. It was originated in China as traditional medicine and introduced to Japan. Over the years, Kampo medicine in Japan has been formulated in a way to suit Japan’s natural features and ethnic characteristics. Based on this traditional Japanese Kampo medicine, we have manufactured a Kampo gargle and Mastic Gel dentifrice. In order to practically utilize the effectiveness of mastic, we have developed a dentifrice (product name: IMPLA CARE) and treated implant periodontitis and severe periodontitis.

Power semiconductor devices for electric power conversion must be able to operate at high temperatures and with high levels of reliability. Therefore, heat resistance and long fatigue lifetime are necessary for the solder joints of these devices.In this paper, we discuss the mechanical properties and the thermal cycling lifetime evaluation of a Sn-Sb binary alloy whose melting temperature can be controlled relatively, and which has excellent high temperature properties. Tensile tests are conducted to determine how the reliability of solder joints using the Sn-Sb alloy is affected by the amount of Sb.We used a Sn-13 wt.% Sb binary alloy as the joint material of a power semiconductor device and investigated the thermal cycling lifetime of the solder joint. It was clarified that the tensile strength of the Sn-Sb binary alloy is proportional to the Sb content and the thermal cycling lifetime increases with increasing tensile strength of the solder. The precipitation strengthening of a SbSn compound leads to improvement of the tensile strength and thermal cycling lifetime.

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