測定精度の一般的特徴として, 各方向の移動距離の忠実性はその運動が大きくなればそれだけ大きな誤差となる. しかし, 我々が目的とする顎運動路の観察は限界運動路よりむしろより機能的な運動動態の解明にあるので, 咬合位付近の運動ほど忠実性がある本装置の特徴は我々の研究目的にマッチしているものと思われる.
1. 本装置の分解能は0.5mmであつた.
2. sensorとマグネットとを結ぶ軸上でマグネットが移動する場合, 各sensorとも1cmまでに直線性を有するが, 2.5cm移動でvertical+2mm, ant-postで+2mm, lateralで±1mmであつた.
3. 3次元的なマグネット移動時の直線性は補正されていないため, 矢状面, 前頭面上での描記特性は特有の歪を示し, マグネットの移動量が大きくなるほど, その歪みは大きくなつた.
4. 差動型であるlateral sensorはマグネットが軸上を移動する場合も, 軸上から偏位した場合も, verticalsenorやant-post sensorよりもその忠実性がきわめてすぐれていた.
5. 下顎運動の速度波形をえるための本装置の微分器は200mm/secまでは正確に測定できるが, それ以上のスピードでは波形に歪をきたした.

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Soldering is one of essential laboratory works in dental technology. However, soldering needs the soldering investment and solder, so that the following problems are inevitable; 1) impossibility of uniform and sound joint, 2) a long working time with various steps, 3) dimensional changes, etc.
Laser welding can be one of methods for conventional soldering. In laser welding the following merits are expectable;
1) all welding is directly done on the master cast
2) a strong joint due to autogenous fusion of parent metals
3) the increase of resistance to corrosion
4) time saving and simple work
5) less dimensional change, etc.
In three previous reports the author investigated tensile strength, bending strength, dimensional changes, working time and so forth as the metallurgical study of laser welding. In the fourth report, the atomosphere and several problems of laser welding were investigated.
In this report, the basic metallurgical studies were summarized and the following were investigated based on the metallurgical studies;
1) laser welding of various prostheses on the master cast
2) an investigation of the joint region and joint form of prostheses with laser welding
3) an improvement of welding surface using the welding stick and double shot technique
4) fabrication of casting plate adopting the separated casting method
5) the repair of prostheses, etc.
Moreover, the possibility of laser application to pin-hole preparation for channel shoulder pin milling technique and reverse pin facing were investigated, and 20 clinical cases were presented and discussed.
As a result it was recognized that laser welding is more excellent than conventional soldering from various standpoints. Designs of prostheses and technical procedures are improved by introduction of laser welding and several new methods were introduced.

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Pitting corrosion is an electro-chemical corrosion frequently observed in metal and alloy, and the pits produced by this corrosion have a fairly good undercut. B. Dunn and M.H. Reisbick applied this corrosion to enable the ceramic to attach to Vitallium. The purpose of this study was to determine the retentive force of the pits for retaining thermo-setting acrylic resin veneers. The metal casting casted by 92% Ni-6% Cr alloy was placed in a 4% NaCl solution and biased positively with respect to a stainless steel electrode. A direct current was passed and by modifying the level and the treatment time, varying degree of pitting corrosion were achieved. After etching, current thermo-setting acrylic resin was veneered. Then all the specimens were subjected to thermal cycling at 4°C and 60° C for two hours. All the specimens were then measured the amount of force required to separate the facing resin from the metal casting. The strongest retention, 100 kg/cm2, were obtained at the following combination of the current density and the treatment time ; 625 mA-6 min, 500 mA-8 min, 375 mA-10 min, 250 mA-18 min. The pits appeared to be effective for retaining thermo-setting acrylic resin veneers.

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In a previous paperl, the principle of pitting corrosion and the factors which affect on the shape of the pits were studied and the retentive force of retainers using pitting corrosion were measured. The result showed that the metal (92% Ni, 6% Cr alloy for crown restorations) surface etched by this electrochemical corrosion provided strong attachment of a thermo-setting acrylic resin to the metal substrate. This report describes a modification of this method for clinical use. The results showed that this new procedure provided stronger retentive force to the metal for bridge restorations (84% Ni, 8% Cr, 5% Cu, 1% Mn alloy) than the procedure used in the previous experiment. An incisal tooth decayed was restored using this new method.

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