Adaptability of titanium casting denture base -Especially the effect of difference by the form of retentional lattice-

随着铸造技术的提高，商用纯钛在齿科领域的应用频率增加，这是亟待解决的一大问题，对商用纯钛铸造义齿的需求也随之上升。但尺寸精度有待进一步提高。本文将纯钛铸造义齿作为影响其变形的因素之一，对其固位晶格形态的适应性进行了研究。作者们进行了探索理想保留晶格形式的实验。在第一个实验中，作者分别对夹持式、网眼式和阶梯式三种类型的凹槽顶部轮廓停止和凹槽顶部交叉超过10mm的图案进行了研究。从牙槽顶向外超出10mm时，上颚的差异均不大。更多的病例停在牙槽顶，离牙槽顶超过10mm，水平面和正面都向右移位，钛铸造义齿变形大到无孔的类型。梯型在长度和水平方向上的膨胀收缩差异较大。在上颚后，边缘部分的差值为从牙槽顶向外超出10mm时阶梯型最大的值。对于梯型保留格，没有得到很好的结果。所采用的网型在长度和水平方向上的膨胀收缩率差异较小，且效果优异。最好的类型是保留格为网格型，轮廓止于肺泡顶部。然后，作者进行了第二次实验，以探索更好的网格类型。在第一次试验中，提出了网型孔洞中存在的熔模影响钛的铸造收缩率。因此，制作了改变网格孔的尺寸、数量和排列的样品。结果表明，在增大补片尺寸并将补片位置置于常规补片位置之外的情况下，获得了尺寸变化不大的铸造义齿。少

Applied frequency to the odontology department area of the commercial pure titanium increases along with the improvement of the casting technology which is one of big problems which should be solved, and the demand of the commercial pure titanium casting denture has risen. However, a further improvement is requested about the dimensional accuracy. In this time authors paid attention as one factor taking part in the deformation and the adaptability of the commercial pure titanium casting denture to the form of the retentional lattice. Authors experimented to grope for the forms of a ideal retentional lattice. In the 1st experiment, authors examined both of the pattern that the outline stops in the alveolous top and the pattern that the alveolous top crosses over 10mm about the type of the holded none, the mesh type, and the ladder type. The discrepancy of the palate when exceeding outward from the alveolus top by 10mm of the type of the holed none was large. I was able to ask about the … More case to stop in the alveolus top, excess from the alveolus top by 10mm, and both horizontal planes and frontal sides were displaced right, and the deformation of the titanium casting denture be large to the type of the holed none. The difference of the expansion shrinkage of length and horizontal direction was large in the ladder type. Moreover, after the palate, the discrepancy of the edge part indicated the value with the biggest ladder type when exceeding outward from the alveolus top by 10mm. As for the ladder type as the retentional lattice, an excellent result was not obtained. The mesh type obtained the result in which the difference of the expansion shrinkage of length and horizontal direction was small, and excellent. The best type is that retentional lattice is the mesh type and the outline stops in the alveolus top. Then, authors have done the 2nd experiment to grope for a better mesh type. In the 1st experiment , it was suggested that the investment which existed in the hole of the mesh type influence the casting shrinkage of titanium. Therefore, the sample that the size, number, and the arrangement of the hole of the mesh were changed was manufactured.As a result, in the condition of that the size of mesh was enlarged, and the position was given outside from the usual one, authors obtained the casting denture with little dimensional changes. Less