Clinical evaluation of ProTaper Ni-Ti rotary instruments in preparation of curved root canals

【Objective】To investigate the clinical effects of ProTaper Ni-Ti rotary instruments in preparation of curved root canals. 【Methods】 One hundred and eighty root canals of 180 patients were equally divided into two groups at random. The cases in experimental group were instrumented by ProTaper Ni-Ti rotary instruments using ProTaper technique(NT group); those in control group were instrumented by stainless steel hand K-files using Stepdown technique(SS group). The shape of root canalal and effects of obturation were evaluated with radio graphs during and after operation. The incidence of post-operative pain and the rate of instrument fracture were recorded. 【Results】The preparation time was(3.68±0.82) min in experimental group and(8.38±0.32) min in control group. The rate of root canal deformity after preparation was 9.32% in control group and 2.30% 93.12% of the canals in experiment group were obsturated as compared with 80.51% in control group. The incidence of post-operative pain were 10.00% in Ni-Ti roup while 37.50% in control group.【Conclusions】 Under clinical conditions, ProTaper NiTi rotary instruments can prepare root canal effectively and safely, the ProTaper Ni-Ti rotary instrumentation technique is an efficient root canal preparation method for curved canals. But fracture of the instrument should be avoided.