针道和粘接剂对镍铬合金与牙釉质粘接强度的影响

目的:比较针道固位型、不同粘接剂对镍铬合金与牙釉质初次粘接、再次粘接的抗拉粘接强度的影响.方法:将60颗新鲜离体牛恒前牙随机分为6组,每组10颗,以垂直釉质粘接面预备针道数(0、1、2),Panavia F和Super-Bond C&B两种树脂粘接剂为变量进行组合.分别测量镍铬合金与牙釉质的初次粘接、再次粘接的抗拉粘接强度.结果:采用Super-Bond C&B粘接剂的抗拉粘接强度(11.82 MPa)高于采用Panavia F者(9.28 MPa),差异有统计学意义(P＜0.001);而针道对抗拉粘接强度无显著影响(P=0.394).初次粘接与再次粘接的抗拉粘接强度差异无统计学意义(P=0.969).结论:使用Super-Bond C&B粘接剂对镍铬合金与牙釉质进行粘接的抗拉粘接强度高于Panavia F,可提高粘接桥的粘接固位力;与粘接界面垂直的针道固位型对镍铬合金与牙釉质的抗拉粘接强度无明显影响;通过去除残余粘接树脂和对金属粘接面喷砂处理可实现有效的再次粘接,其抗拉粘接强度可达到初次粘接水平.

Effects of pins and bonding agents on the tensile strengths of Ni/Cr alloy bonded to enamel

OBJECTIVE: To evaluate the effects of pin retention form and different bonding agents on the tensile bond and re-bond strength of Ni/Cr alloy to the enamel. METHODS: Sixty bovine permanent incisors were randomly divided into 6 equal groups by the variables of the numbers (0, 1 or 2) of pins to be prepared and bonding agents (Panavia F and Super-Bond C&B). The pin 1mm in diameter and 1mm in depth was prepared vertically to each enamel surface in the groups to be with pins. Cast Ni/Cr alloys cylinders were made and bonded to respective enamels using two different agents. Tensile strengths were tested. After residual visible resin on the debonded surfaces being removed, specimens were re-bonded and tested in the same way as initial bonding. RESULTS: The tensile strength of Super-Bond C&B groups (11.82 MPa) was significantly higher than those of Panavia F groups (9.28 MPa, P<0.001). There was no significant difference of the tensile strength among the groups with one pin, two pins or without pins (P=0.394). There was no significant difference between the bond and re-bond tensile strength (P=0.969). CONCLUSION: Super-Bond C&B has significantly higher tensile strength than Panavia F, and is good for the retention of resin bonded fixed partial denture. Pins, which are vertical to the bonding surfaces have little effect on the tensile strength. The re-bonding can be successfully achieved by removing the residual visible resin and sandblasting the metal surfaces and the tensile strength is unchanged.