The Quality of Root Canal Preparation and Root Canal Obturation in Canals Treated with Rotary versus Self-adjusting Files: A Three-dimensional Micro-computed Tomographic Study

Aim: The study was designed to quantitatively evaluate the quality of root canal preparation and root canal obturation in canals treated with either rotary or self adjusting files, using three-dimensional micro computed tomographic (CT) analysis. Methodology: Pair-matched root canals were instrumented with either rotary nickel-titanium files or self-adjusting files following the manufacturers' instructions. The area of the canal wall unaffected by the preparation procedure was analyzed using before and after micro-CT images. Root canal obturation was done using lateral compaction with gutta-percha and AH26 (Dentsply-DeTrey, Konstanz, Germany). Teeth were scanned a third time, and the adaptation of the filling material to the canal walls was evaluated three-dimensionally by micro-CT analysis and the area of canal wall untouched by the filling was determined. The correlation between these two parameters within each of the groups was studied using the Pearson correlation test. Results: A high percentage of unaffected root canal walls (60% +/- 14%) and areas untouched by the root canal filling (45% +/- 15%) were found in canals treated with rotary files. Both parameters were significantly smaller in canals treated with self-adjusting files (17% +/- 9% and 17% +/- 11%, respectively) (p < 0.01). No correlation was found between these parameters within each of the groups. Conclusion: Within the limitations of the present study, the self-adjusting files allowed better cleaning and shaping and better adaptation of the root canal filling than those allowed by rotary files. (J Endod 2010;36:1569-1573)