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，商品化纯钛在牙科领域的应用频率越来越高，商品化纯钛铸造义齿的需求也随之上升。然而，尺寸精度还有待进一步提高。在此期间，作者关注了商品纯钛铸造义齿的变形参与和对支持点阵形状的适应性。作者们通过实验探索理想的视网膜晶格的形式。在第一个实验中，作者考察了轮廓停在牙槽顶的图案和牙槽顶跨过10 mm的图案，大致分为无牙槽、网状牙槽和梯形牙槽。无孔型牙槽顶向外超出10 mm时，上颌相差较大。我能够问到关于…的事情更多的病例停在牙槽顶部，从牙槽顶部超出10 mm，水平面和前侧都向右移位，钛铸造义齿的变形量较大，为无孔型。梯形的长度方向和水平方向的膨胀收缩差异较大。此外，在上颌后，边缘部分的差异表示从牙槽顶部向外超出10 mm时梯形最大的数值。对于梯形视网膜点阵，效果并不理想。网格型式得到的结果是长度方向和水平方向的伸缩量相差很小，并且效果很好。最佳类型为网格型，轮廓止于牙槽顶部。在此基础上，作者进行了第二次实验，摸索出一种较好的网格类型。在第一个实验中，提出了网孔中存在的包埋物对钛铸件缩松的影响。为此，制作了改变网格大小、数量和孔洞排列的试件，在扩大网格大小、改变网格位置的情况下，获得了尺寸变化不大的铸造义齿。较少

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