Study on test method of impact strength for dental brittle materials.

假定其宽度为10mm，厚度为10.0^<**>0.2mm，用于测量JIS中刚性塑料的冲击强度。为标准样品成型时聚合均匀的热固化树脂提供了相对稳定的结果。发现不均匀度大，采用复合树脂填充。原因是样本量大。其他原因是气泡与样品混合，灌装操作不当。这些原因与材料的力学性能无关。牙科材料太贵了，我们必须努力做小样品。最后的目的是试样的大小作压缩检验件的程度。存在各种各样的问题，样品在一列中没有形成H型。我对9种H型样品的缺口位置、尺寸、形状进行了检验。在10mm高的样品中心，我在两个刀片上形成了0.5mm深1.0 mm的缺口，厚度为0.33 mm的金刚石盘。样品在夹具上保持4 - 4毫米，并将其提供给检查。撞击位置比缺口高出2mm。我无法测量冲击强度时，没有遵循切割超过1毫米的样品，这给了0.5毫米的缺口。试样的冲击强度不受切割部厚度的影响，试样的冲击强度差异最大。我加深了切口，冲击强度变小了。当我能够完全测量缺口为1mm的样品的冲击强度，但切割部分变为1mm以上时，强度确实突然下降。在某种程度上，由于JIS方法的不同，得到了这次的结果。期望在此基础上制定新的牙用材料标准。并对粘结强度与冲击强度的关系进行了探讨。

It is assumed it with 10mm wide in thickness of 10.0^<**>0.2mm to a measurement of examination piece used for the measurement of impact strength of being rigid plastic in JIS.The result that became stable comparatively was provided to the heat curing resin that polymerization was homogeneous at the time of form of standard sample. Big unevenness was recognized in a result in composite resin for the filling. The cause being large a volume of sample. Other cause were of mixture of air bubble to sample and a delinquent filling operation. These causes are the things that there is not relation with mechanical property of materials. We must do an effort making small sample, because dental material so expensive. Last aim is the thing that size of sample is made compression examination piece degree. There were various kinds of problems and sample did shape to H type in a column. I got examination about a position of notch, size, shape about sample of 9 kinds H type. In the center of sample of 10 mm high, I formed a notch of 0.5mm deep and 1.0 mm in both blades diamond disk of thickness 0.33 mm. Sample maintained i4 4 mm in jig and offered it to an examination. Impact position did it with 2mm upward than a notch. I was not able to measure impact strength when did not follow a cut more than 1mm in the sample which gave a notch of 0.5mm. There was not impact strength by difference of thickness of cut department most difference in the sample which was able to be measured. I deepened a cut and impact strength became small. When I was able to measure entirely impact strength in sample of notch of 1mm and but cut portion became it to more than 1mm, strength did decrease suddenly. The value that was in a manner different as a result of JIS method was got to the result of this time.I expect that new dental materials standard on the basis of this result is established. I tried to get consideration about relation of bonding strength and impact strength too.