Microscopic Evaluation of Dentinal Defects after Root Canal Preparation with Different Hand and Nickel-Titanium Files; An In Vitro Study

Background

Effective endodontic instrumentation aims to remove microorganisms, debris, and tissue from the root canal while maintaining dentinal integrity. This study compares dentinal defect incidence following canal preparation with different hand files, nickel-titanium rotary files, and reciprocating files.

Materials and Methods

Eighty single-rooted mandibular premolars with mature apices were collected. Four groups (n = 20) were established based on canal patency establishment, canal preparation technique, irrigation solution, and final irrigation. After root sectioning at 3 mm, 6 mm, and 9 mm from the apex, slices were examined under a stereomicroscope, and dentinal defects were recorded. A second examiner reviewed the images.

Results

The results showed significant difference of P = 0.031 among Hand files vs. Rotary ProTaper files: In Hand files vs. Reciprocating WaveOne files significant difference was P = 0.048, and for rotary ProTaper files vs. Reciprocating WaveOne files: No significant difference (P = 0.643). Dentinal defect counts were similar at 3 mm, 6 mm, and 9 mm. Statistically significant variation was observed between hand files and rotary files, as well as hand files and reciprocating files.

Conclusion

Both rotary and reciprocating files showed a statistically significant increase in dentinal defect incidence compared to hand files. However, clinical implications should be considered cautiously. Instrumentation technique selection should be based on clinical context, operator experience, and patient factors. Further clinical studies are needed for validation.