新型镍钛机动器械预备椭圆形根管牙本质微裂比较

Comparison of dentinal microcracks of oval shaped canal prepared with different nickel-titanium instruments

目的通过观察3种新型镍钛机动器械预备椭圆形根管后牙根牙本质微裂情况,比较不同根管预备器械对根管预备后牙根抗折能力的影响。方法收集65个具有椭圆形单根管的下颌前牙,分为3个试验组(每组n=20)和对照组(n=5),试验组分别用自调节锉(SAF)、ProTaper Universal和ProTaper Next进行根管预备,对照组不进行根管预备。离根尖3、6、9mm处横断牙根,体视显微镜下评估牙本质微裂情况。结果ProTaper Universal组根折发生率高于ProTaper Next组和SAF组(P<0.05)。ProTaper Next组和SAF组的牙根折裂发生率比较,差异无统计学意义(P>0.05)。结论新型镍钛器械ProTaper Next和SAF根管预备后牙本质微裂形成少,能降低根管治疗后牙根折裂风险。

Objective To compare the effect of different nickel-titanium rotary files on fracture resistance of teeth by observing status of dentinal microcracks after root canal preparation with.Methods 6 5 mandibular anterior teeth with single oval canal were randomly divided into three experimental groups （n=20）and a control group （n=5）,SAF、ProTaper Universal and ProTaper Next system were used to prepare root canal in experimental groups,while the control group were left unprepared.Roots were sectioned from 3,6,9 mm to the apex,its status of dentinal microcracks was evaluated under a stereomicroscope.Results Root fracture inci-dence rate of group ProTaper Universal was significantly higher than that of group SAF and group ProTaper Next （P〈0.05）. There were no statistically significant differences in incidence rate of dentinal microcracks between group SAF and group ProTaper Next （P〉0.05）.Conclusion Roots with oval shaped canal prepared with SAF and ProTaper Next produce less dentinal microc-racks,which decrease risk of vertical root fracture.