根管治疗后下颌磨牙冠缺损类型与冠根折关系的临床分析

Clinical Evaluation of Relationship between Crown Defect types and Crown fractures of Root-canal-treated Mandibular Molars

目的 :观察根管治疗后的下颌磨牙冠缺损类型与冠根折的关系。方法 :回顾观察根管治疗后的 976个下颌磨牙的冠根折发生情况 ,其中牙合面 (O)、近中牙合面 (MO)、远中牙合面 (DO)、近中 -牙合面 -远中 (MOD)及牙冠三面缺损(TD)的牙齿数量分别为 2 4 6、2 96、2 15、12 3、96个。结果 :5种缺损类型的下颌磨牙的冠根折发生率分别为 14 .6 3%、2 6 .35 %、19.5 3%、37.4 %、32 .2 9% ,经 χ2 检验分析 ,MOD和TD的冠根折断率最高 ,牙合面缺损的折断率最低。结论 :根管治疗的下颌磨牙冠缺损达牙冠三面者建议用覆盖牙尖的修复体修复 。

Objective: To evaluate the relationship between crown defect types and crown fractures of root-canal-treated mandibular molars. Methods: 976 root-canal-mandibular molars were retrospectively observed if the teeth were fractured, occlusal (O), mesial-occlusal (MO), distal-occlusal (DO), mesial-occlusal-distal (MOD), three surface defects (TD) of crowns were 246, 296, 215, 123, 96, respectively. Results: The tooth fracture rate of O, MO, DO, MOD, TD groups were14.63%, 26.35%, 19.53%, 37.4%, 32.29%. The analysis of χ 2 showed the tooth fracture rate of MOD and TD groups were the highest, the fracture rate of O group was the lowest. Conclusion: Within the limitations of this study, root-canal-treated mandibular molars with three surface defects was suggested to place the restorations of occlusal coverage.