Carter J M, Sorensen S E, Johnson R R, Teitelbaum R L, Levine M S
J Biomech. 1983;16(10):841-8. doi: 10.1016/0021-9290(83)90008-8.
Plano-parallel specimens of human dentin cut from vital and endodontically treated teeth were tested by the punch shear test. Shear strength values were found to positively correlate with approximate toughness values. Statistically significant differences were found between shear strength and toughness values for vital and endodontically treated teeth, the latter showing lower values. The clinical impression that endodontically treated teeth are weaker and more brittle than vital teeth has therefore been quantitated. Anatomically different teeth or the methods used to store and cut teeth could not be consistently correlated with punch shear and toughness values. When dentin slices were constrained during punching so that bending was prevented, the precision of the results was improved and higher values were recorded.
采用冲压剪切试验对从活髓牙和经牙髓治疗的牙齿上切取的平面平行的人牙本质样本进行测试。发现剪切强度值与近似韧性值呈正相关。活髓牙和经牙髓治疗的牙齿在剪切强度和韧性值之间存在统计学上的显著差异，后者的值较低。因此，经牙髓治疗的牙齿比活髓牙更脆弱、更易碎这一临床印象得到了量化。解剖结构不同的牙齿或用于储存和切割牙齿的方法与冲压剪切和韧性值之间没有一致的相关性。当在冲压过程中对牙本质切片进行约束以防止弯曲时，结果的精度得到提高，记录到的值更高。
