根管预备程度对中国人牙根强度的影响

The effect of root canal instrumentation on Chinese tooth root strength

目的探讨根管预备程度对中国人牙齿力学性能的影响。方法选取中国成人离体单根管下颌前磨牙40颗,随机分为A、B、C、D 4组,分别预备至0.04锥度#25、0.06锥度#25、0.04锥度#30、0.06锥度#30,全部常规侧方加压充填根管。置于万能力学实验机加压,记录牙根折裂时最大载荷。结果 A组(182.17±49.22)N与B组(146.28±56.54)N、C组(98.14±12.25)N与D组(86.10±29.44)N无统计学差异(P>0.05),A组与C组、B组与D组有统计学差异(P<0.05)。结论根管预备时锥度和号数增加均会引起牙根强度的降低,但号数的变化对牙根强度影响更大。

Objective To discuss the effect of root canal instrumentation on mechanical characters of Chinese tooth root. Methods A total of 40 mandibular premolars with single canal extracted from Chinese adults were randomly divided into 4 groups（ A,B,C,D）,which were all prepared by rotary instruments up to #25 0. 04 taper,#25 0. 06 taper,#30 0. 04 taper and #30 0. 06 taper. All specimens were filled with gutta percha and AH-Plus sealer with lateral condensation filling technology. The specimens were then submitted to compressive strength testing by a universal testing machine. The highest compressive strength value was recorded when each root exhibited vertical fracture. Results No significant differences were obtained either between Group A（ 182. 17 ± 49. 22） N and Group B（ 146. 28 ± 56. 54） N or between Group C（ 98. 14 ± 12. 25） N and Group D（ 86. 10 ± 29. 44） N（ P〉 0. 05）. However,there were significant differences between Group A and Group C as well as Group B and Group D（ P 〈0. 05）. Conclusions Increased taper and size of file tip of root canal instrumentation could lead to decreased root strength,and the size of file tip exhibited more influences.