A Retrospective Study of Endodontic Treatment Outcome between Nickel-Titanium Rotary and Stainless Steel Hand Filing Techniques

Aim: The purpose of this study was to compare the periapical healing of molar root canal treatment using two instrumentation techniques. Methods: A total of 225 maxillary and mandibular first and second permanent molars endodontically treated by undergraduate or postgraduate students were randomly selected from a computerized hospital database of which 110 molars had been prepared using a hybrid rotary technique with nickel-titanium instruments (group NR) and 115 with hand stainless steel files (group HF). Patients were recalled and the teeth were examined both clinically and radiographically for signs of periapical inflammation. Results: Some 19% and 39% of teeth in the NR and HF group, respectively, were judged to have some form of procedural errors. A higher rate of periapical healing was noted for NR (77%) than the HF group (60%) (p < 0.05). Factors contributing favorably to treatment outcome included the use of rotary technique, maxillary molar, experienced operator, and absence of preoperative radiolucent lesion. Conclusion: There was a higher incidence of procedural errors and a lower success rate for primary root canal treatment of teeth prepared with stainless steel files compared with the use of NiTi instruments in a continuous reaming action. (J Endod 2009;35:938-943)