[目的]探讨牙冠延长术治疗牙体劈裂达到龈下较深部位患者的疗效.[方法]选取2014年1月至2016年1月在本院诊治的因牙体劈裂达到龈下较深部患者120例(120牙),采用随机数表法分为观察组和对照组,每组60例(60牙).观察组采用牙冠延长术暴露断面、对照组采取牙龈切除术暴露断面,术后再行常规桩冠修复,对比两组术前、术后6周的菌斑指数(PLI)、探诊深度(PD)、龈下出血指数(SBI)及美学效果.[结果]两组术前牙龈PLI、PD、SBI值比较差异均无统计学意义(P＞0.05);术后6周,两组患者的牙龈PLI、PD、SBI值较术前均显著减小,观察组减少更明显,其差异具有统计学意义(P＜0.05);术后6个月,观察组患者牙龈颜色、与邻牙和面型是否协调、修复体的颜色及形态是否与邻牙一致的满意率分别为85.00％、81.67％、88.33％,与对照组的80.00％、78.33％、80.00％比较差异无统计学意义(P＞0.05).[结论]牙冠延长术治疗牙体劈裂达到龈下较深部位患者,PLI、PD、SBI值均减少,且具有较好的美学效果,值得临床推广应用.“,”[Objective] To explore the application of crown lengthening in the treatment of dental repair in patients with teeth splitting to the deeper parts to subgingival.[Methods]Selected January 2014 to 2016 Janu-ary in the dental clinic of our hospital for diagnosis and treatment of 120 cases(120 teeth due to dental splitting to gingival deep patients were studied by randomly divided into study group and control group,60 cases(60 teeth),the study group with crown lengthening surgery exposed section,the group take gingival resection ex-posed section,postoperative again conventional post crown repair,compared two groups of patients before surgery and after 6 weeks of plaque index(PLI),probing depth(PD),bleeding index(SBI)and aesthetic effect.[Results]Before the operation,the study group and the control group PLI,PD,SBI in gingival differ-ence were not statistically significant(P ＞0.05);after 6 weeks,the two groups of patients with PLI,PD,gingival SBI values were significantly decreased compared with preoperative,the difference was statistically significant(P ＜0.05),the study group of teeth PLI,PD,SBI gum was lower than the control group,the difference was statistically significant(P ＜0.05);6 months after operation,the study group of patients with gingival color,with adjacent teeth and facial coordination restoration,color and shape are consistent with adja-cent teeth satisfaction rates were 85％,81.67％,88.33％were higher than the control group 80％,78.33％,80％,but the difference was not statistically significant(P ＞0.05).[Conclusion]Crown lengthening surgery used to treat tooth splitting reach deeper parts of subgingival restorative treatment of patients with better clini-cal results.