牙科复合树脂材料与牙体硬组织剪切粘接强度的方向性

目的　考察复合树脂材料与牙体硬组织粘接强度的方向性。方法　采用 2种复合树脂材料及配套的粘接剂 ,分别与牛牙牙釉质和牙本质粘接。测试了剪切力分别沿根尖方向和切缘方向作用的静剪切和冲击剪切强度。结果　 2种复合树脂材料与牙釉质粘接的剪切粘接强度均表现为根尖方向的剪切强度大于切缘方向的剪切强度。在静剪切实验中 ,前者约为后者的 2～ 3倍 (P <0 0 5) ;在冲击剪切实验中 ,前者约为后者的 3～ 4倍 (P <0 0 0 1 )。 2种复合树脂材料与牙本质的粘接强度受作用力方向的影响较小 ,在静剪切实验和冲击剪切实验中 ,2个方向的数据之间差异均无显著性 (P >0 0 5 ,P >0 5)。结论　复合树脂与牛牙牙釉质之间的剪切粘接强度与剪切力作用的方向有关。

The directionality of share adhesive strength between composite resin and dental hard tissue

Objective To inspect the directionality of adhesive strength between composite resins and dental hard tissues. Methods Two kinds of composite resins were bonded with their luting kits to the enamel and dentin surfaces of bovine teeth separately. The dead load shear and impact shear testing were performed from both of root apex direction and cutting edge direction. Results The shear adhesive strength between the enamel and two kinds of composite resins was on the same behavior, that the shear adhesive strength of root apex direction was greater than that of cutting edge direction. In the dead load shear testing, the former was about two to three times of the latter ( P < 0 05). In the impact shear testing, the former was about three to four times of the latter ( P< 0 001). The effect of the direction of acting force was small on the shear adhesive strength between the dentin and two kinds of composite resins. In the both dead load shear testing and impact shear testing, there was no statistically significant difference between the datum of two directional loadings ( P > 0 05, P > 0 5). Conclusion The shear adhesive strength between the composite resins and enamel of bovine teeth is related to the acting direction of the shear force.