摘要
背景:研究表明,桩的植入和牙体剩余量的不同会改变残根内牙本质的应力分布模式,并对桩核修复体的折裂模式产生影响。目的:评价进行纤维桩复合树脂核全冠修复时,在斜向加载条件下牙体剩余量对牙根折裂模式的影响。方法:获取正畸拔除的人单根前磨牙40颗,行根管预备及填充后随机均分为4组,以通过颊侧和舌侧釉质牙骨质界中点并垂直于牙体长轴的平面为参照平面,使得牙体剩余量分别为0,1,2,3 mm,行纤维桩复合树脂核金属全冠修复。修复后进行速率为1 mm/min的45°斜向加载,记录牙根出现折裂时的折裂模式和加载-位移曲线。结果与结论:0 mm组多发生牙颈部折裂,其余3组多发生根中部折裂,0 mm组的总折裂模式与其余3组比较差异有显著性意义(P<0.05),1,2,3 mm组间总体折裂模式比较差异无显著性意义(P>0.05)。在斜向加载条件下,当剩余牙体较少时,修复体易发生牙颈部折裂,纤维桩对牙根起到了保护作用,但临床失败概率增加;随着牙体剩余量的增加,折裂模式发生改变,从颈缘向根方转移。表明临床上对残根行纤维桩核冠修复时,应尽量保留冠部较多的牙体组织。
BACKGROUND： Studies have demonstrated that implantation of pile and different amount of residual tooth can change the stress distribution patterns of the tooth dentin within the residual root,and have an effect on the fracture mode of post-core restoration. OBJECTIVE： To evaluate the effects of the different amount of residual tooth on the fracture mode under oblique loading conditions in fiber pile composite resin core full crown restoration. METHODS： Forty single rooted premolars extracted from orthodontic patients were divided into four groups after root canal preparation and filling. The plane going through buccal and lingual enamel cementum border midpoint and perpendicular to the long axis of the tooth was taken as the reference plane,so that the remaining amount of the tooth were 0,1,2,3 mm. Fiber pile composite resin core metal full restoration was conducted. After the repair,the oblique loading at 45° and at the rate of 1 mm/min was conducted. Fracture mode and load-displacementcurve when root fracture occurred were recorded. RESULTS AND CONCLUSION： The tooth neck fracture usually occurred in the 0 mm group,and central root fracture usually occurred in the remaining three groups. There was a significant difference in the total fracture mode between 0 mm group and the remaining three groups（P〈0.05）. There was no significant difference in the total fracture mode between 1,2 and 3 mm groups（P〉0.05）. In oblique loading conditions,when the remaining tooth structure was small,the prosthesis was prone to have dental neck fracture. Fiber posts played a protective role in the tooth root,but the clinical probability of failure increased. The fracture mode was changed with the increase of residual tooth amount,transferring from the neck edge to the root. These results demonstrate that we must retain more tooth tissue from the crown in the restoration of residual root with fiber post-core crown.
出处
《中国组织工程研究》
CAS
北大核心
2015年第43期6971-6976,共6页
Chinese Journal of Tissue Engineering Research
基金
广东省科技厅社会发展项目(2011B080701010
2012B061700066)~~
