摘要：
Objective To compare the effect on the flow conditions of adhesives and the retention force of restorations among different cement?retained methods of implant?supported fixed prostheses. Methods Four common cement?retained methods were selected, including the occlusal hole for screw access (OH), the lingual hole for adhesives overflow (LH), the resin replica for titanium abutment (RR), and the traditional cement?retained method (the control group). The adhesive used in this study was resin?modified glass ionomer cement. The two?dimensional analysis models of computational fluid dynamics (CFD) were established. The flow conditions of adhesives in the adhesion process was analyzed by the CFD analysis. The internal filling ratio and the amount of neck overflow of adhesives below the edge of the prosthesis were calculated. Ten zirconia prostheses in each group were processed and cemented. The retention force was examined by mechanical tensile experiments in vitro . Results The CFD analysis showed the internal filling ratio of adhesives from high to low was the LH group, the OH group, the RR group and the control group. The amount of neck overflow of adhesives below the edge of the prosthesis from less to more was the RR group, the OH group, the LH group and the control group. The retention force was (240.7± 33.9) N in the control group, (278.2±59.1) N in the OH group, (292.9±47.9) N in the LH group, and (262.8± 59.4) N in the RR group. There was a statistically significant difference in the retention force between the LH group and the control group (P=0.029). There was no significant difference among the other groups (P> 0.05). Conclusions The modified cement?retained methods can effectively reduce the amount of neck overflow of adhesives, and improve the filling condition of adhesive in the adhesive clearance to ensure the retention force of the prostheses. Clinically, the appropriate modified cement?retained method should be selected according to the three?dimensional position of the implant and the position of prosthetic margin.%目的 研究种植固定修复中不同粘接固位形式对粘接剂流动状态及修复体固位力的影响.方法 选取4种常见的粘接固位形式,分为对照组(传统粘接固位)、开孔组(面开孔)、排溢孔组(舌面开孔)、代型组(使用粘接代型),选用树脂加强型玻璃离子粘接剂;建立计算流体力学二维分析模型,利用计算流体力学模拟粘接过程中粘接剂的流动状态,并计算粘接剂间隙内粘接剂的充盈比及修复体边缘下粘接剂的量.根据组别加工40个全瓷修复体(每组10个),完成相应粘接,进行拉伸实验,比较各组修复体固位力.结果 计算流体力学分析显示,粘接剂间隙内粘接剂的充盈比从大到小依次为排溢孔组、开孔组、代型组、对照组,修复体边缘下粘接剂的量从小到大依次为代型组、开孔组、排溢孔组、对照组.对照组、开孔组、排溢孔组、代型组修复体固位力分别为(240.7±33.9)、(278.2± 59.1)、(292.9±47.9)、(262.8±59.4)N,其中排溢孔组显著大于对照组(P=0.029),其余组间差异均无统计学意义(P>0.05).结论 3种改良的粘接固位形式均能有效减少种植固定修复粘接过程中粘接剂的龈下溢出,并改善粘接剂在粘接剂间隙内的充盈情况,保证修复体固位力.临床应根据种植体三维位置、修复体边缘位置等实际情况选择合适的粘接固位形式.
