Clinical Evaluation of New Ni-Ti Rotary Instruments in Preparation of Curved Root Canals

To evaluate the clinical effect of a set of new nickel-titanium rotary instruments, namely ProTaper, in preparation of curved root canals. Sixty-four teeth with curved root canals were managed by ProTaper rotary instruments using crown-down technique and obturated with lateral condensation method. The effect of preparation and obturation was analyzed with radiographs before, during and after operation.The instruments kept the curvature and flow of curved canals very well, and the continuously tapered root canal shape was achieved in all cases. There was no transportation, apical blockage, ledge, but two fractured files. The operative time was short and endodontic flare-up seldom occurred.[Conclusion] The ProTaper Ni-Ti rotary instruments can prepare curved root canals effectively and quickly. Meanwhile, the problem of instrument separation due to many reasons such as variations in canal anatomy and cyclic fatigue of instruments should be prevented.