Comparison of dentinal microcracks of oval shaped canal prepared with different nickel-titanium instruments / 重庆医学

ABSTRACT

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 (P0.05).Conclusion Roots with oval shaped canal prepared with SAF and ProTaper Next produce less dentinal microc-racks,which decrease risk of vertical root fracture.