Comparison of the self-adjusting file with rotary and hand instrumentation in long-oval-shaped root canals

The aim of this study was to compare the root canal debridement ability of the self-adjusting file (SAF) with ProFile rotary (PF) and hand filing (HF) instrumentation in long-oval-shaped canals.

Extracted human teeth (n = 30) were selected on the basis of a root canal ratio of ≥2.5:1 measured 5 mm from the root apex. Each group (n = 10) was matched with regard to the average root canal ratio. Canals were filled with a radiopaque contrast medium (Vitapex) and instrumented by using SAF, PF, or HF with 20 mL of saline irrigation. Teeth receiving irrigation alone served as controls. Preoperative and postoperative radiographs were taken and submitted to digital subtraction, and the percentage reduction of contrast medium was quantified at 0-5 mm and >5-10 mm from the apex. Values were compared by using 1-way analysis of variance and unpaired t tests.

In the 0- to 5-mm segment, the SAF, PF, and HF removed 80.6% ± 14.1%, 84.2% ± 7.7%, and 76.5% ± 10.2% of the contrast medium, respectively (P > .05). In the >5-to 10-mm segment, the SAF, PF, and HF removed 75.5% ± 10.8%, 72.3% ± 12.0%, and 60.9% ± 11.3% of the contrast medium, respectively, with significantly more material removed by SAF compared with HF (P < .05). There was significantly more contrast medium removed by using combined instrumentation and irrigation compared with irrigation alone (P < .01).

All 3 techniques removed contrast medium equally well from the 0-to 5-mm segment of long-oval-shaped canals. The SAF performed significantly better than hand filing in the >5-to 10-mm canal segment.