聚乳酸可吸收根管桩修复残根后的抗折力研究

Experiment study on fracture resistance of endodontically treated residual root by polylatic acid absorbable intracanal post

目的:探讨聚乳酸(PLA)可吸收根管桩修复残根后的抗折力。方法:选择牙根长度、形态一致的离体下颌前磨牙24个,常规根管治疗和充填后,去除牙冠,并将其随机分为3组(每组8个);分别采用PLA可吸收根管桩覆以PLA薄膜、玻璃纤维桩及复合树脂短桩固位,进行桩核树脂冠修复;然后采用电子万能材料测验机检测各组试件的抗折力,并观察其折裂模式,所得数据用LSD双侧检验进行两两比较。结果:PLA可吸收根管桩组和玻璃纤维桩组的抗折力(N)分别为1022.44±359.70、1168.33±193.50(P>0.05),而分别与复合树脂短桩组(1767.36±677.20)相比,差异均有统计学意义(P<0.05);3组试件的折裂模式均为有利性牙折。结论:聚乳酸可吸收根管桩修复残根后的抗折力低于复合树脂短桩,但能满足临床需要。

AIM： To investigate the fracture resistance of endodontically treated residual root by polylatic acid absorbable intracanal post restoration. METHODS： 24 extracted human mandibular premolars were treated by root canal therapy and canal obturation, then divided into 3 groups randomly（ n = 8）. The teeth in group A, B and C were restored with polylatic acid absorbable intracanal posts covered with PLA film, glass fiber posts and short composite resin post respectively, and with composite resin crowns. Each specimen was subjected to a load on INSTRON 5567 material testing machine until failure. Then fracture resistance was compared statistically by one-way ANOVA and followed by LSD test for multiple comparisons. Fracture modes were visually examined. RESULTS： The of fracture resistance（N） of group A, B and C was 1022.44 ±359.70,1168.33 ± 193.50 and （ 1767.36 ± 677.20） respectively （P 〈 0.05）. Group A vs B （P 〉 0.05 ）, group C vs group A or B （ P 〈 0.05 ）. The fracture modes of all the teeth were favorable. CONCLUSION ： Fracture resistance of residual roots endodontically treated by polylatic acid intraea- nal posts and PLA film is lower than that by short composite resin post, but might meet the needs of clinical practice.