不同修复方法对邻(牙合)缺损的下颌前磨牙根管治疗术后抗折性能影响的研究

摘要

目的:比较不同修复方法对邻(颌)缺损的下(颌)前磨牙根管治疗术后抗折强度的影响.方法:将50颗离体下颌前磨牙随机分为A、B、C、D、E五组,每组10颗.A组(对照组):完整离体牙,不做任何处理.其它四组(实验组)样本牙经根管治疗并制备邻上缺损.B组:光固化树脂直接充填；C组:树脂充填+铸造全冠修复；D组:铸造桩核+铸造全冠修复；E组:纤维桩树脂核+铸造全冠修复.所有样本牙在电子万能试验机上以与牙体长轴成30°角、1mm/min速度加载直至样本折裂,记录样本折裂时的载荷数值与折裂模式,对数据进行统计分析.结果:A、B、C、D、E组的折裂载荷分别为(952.93±102.03)、(383.97±46.31)、(733.51±54.94)、(604.76±123.73)和(893.44±87.08)N.五组之间两两比较,只有A、E两组之间差异无统计学意义,其余差异均有统计学意义；A、B、C、D、E组产生不可修复性折裂(根折位于包埋树脂平面以下)的样本数分别为0、2、1、9、3,其中D组牙体的折裂模式与其它三组差异均存在统计学意义,剩余三组间两两比较差异无统计学意义.结论:纤维桩树脂核联合全冠修复可作为邻(颌)缺损的前磨牙根管治疗术后的优选修复方式.%Objective:To compare the fracture resistance ofendodontically treated premolars with proximal-occlusal defects with different restorations.Methods:Fifty recently extracted intact mandibular premolars were randomly divided into five groups (n=10).Group A (control group):intact teeth without any treatments.Other groups were prepared ofproximal-oc-clusal defects followed by RCT.Group B:filled with a light-curing composite resin.Group C:restored with light-curing composite resin filling and cast full crowns.Group D:restored with cast post-cores and crowns.Group E:restored with fiber posts and resin cores and cast full crowns.All specimens were loaded in a universal testing machine at a speed of 1.0mm/min with an angle of 30 degrees to the long angle of the teeth.Fracture loads and models were recorded and analyzed statistically.Results:Mean fracture loads of five groups were as follows,respectively.Group A:952.93± 102.03N,group B:383.97± 46.31N,group C:733.51± 54.94N,group D:604.76± 123.73N,group E:893.44± 87.08N.There was no significant difference between group A and group E.The rest were statistically significant.The number ofunrepairable fracture (under the embedding resin plane) in group A,B,C,D,E were 0,2,1,9,3,respectively.The differences were statistically significant between group D and the other groups.There was no significant difference among B,C,E groups.Conclusion:Fiber posts and resin cores combined with full crown could be used as the first choice to restore endodontically treated premolars with proximal-occlusal defects.