桩核冠修复与牙根折裂的临床分析

The clinical analysis of the fracture of root repaired by post-core-crown technique

目的:分析和探讨临床上桩核冠系统修复后导致牙根折裂的可能因素。方法:对在遵义医学院附属口腔医院修复科制作的723件桩核冠修复体进行追踪调查,主要检查修复的牙位,桩核冠设计形式及修复完成后的使用情况,分析桩核冠修复体产生牙根折裂的原因。结果:28件牙根折裂的桩核冠修复体,均发生于铸造金属桩核冠,其中存在牙合干扰障碍因素的为22件,占牙根折裂修复体总数的78.57%;无完整牙本质肩领的为10件,占牙根折裂修复体总数的35.71%;牙本质肩领高度小于1 mm的为20件,占牙根折裂修复体总数的71.42%;桩核长度小于根长1/2者为10例,占35.71%;桩核直径大于牙根直径1/3者为8件,占28.57%。结论:在桩核冠的修复系统中,导致牙根折裂的原因是多方面的,可能与桩核材料的弹性模量、牙位、牙合关系的调整、牙体的预备、桩核长度及直径的设计等密切相关。

Objective To analyse and discuss the possible clinical factors of the fracture of root repaired by post - core - crown tech- nique. Method 723 post- core- crown restorations were investigated from department of prosthodontics,affiliated hospital of Zunyi Medi- cal College, and inspected mainly include dental positions, design modes and working conditions. To analyse reasons of root fracture. Results All 28 root fracture restorations were the cast metal post and core crowns,in which 22 ones were fractured because of occhsal interference, 10 ones because dentine ferrule were incomplete,20 ones because dentine ferrule were less than 1 millimeter, 10 ones because the length of postcore were less than 1/2 the length of root and 8 ones because the diameter of post - core were greater than t/3 the diameter of root,ac- counting for 78.57% ,35. 71% ,71.42% ,35.71% and 28. 57% of all 28 root fracture restorations res - pectively. Conclusion The reasons of root fracture are various in all kinds of post - core crown restorations ,which could be related to elastic modulus of the post - core materi- al, dental positions, adjustment of occlusion, tooth preparation, and the design of post - core＇s shape,length , diameter and so on.