Efficacy of irrigation with rotary instrumentation

The purpose of this study was to evaluate the efficacy of a handpiece-mounted irrigation device and compare it to irrigation with a syringe and needle in the apical 5 mm of the root canal system. Twenty matched pairs of extracted teeth were used. The only variable within each matched pair was the method of irrigation. A syringe and needle were used in group A and the handpiece-mounted system in group B. Sections 1, 3, and 5 mm from the working length were examined microscopically, and images of the slides were digitized. The percentage of canal space occupied by pulpal and dentinal debris was calculated to be 6% +/- 12.7% in group A, versus 3.8% +/- 7% in group B (p = 0.264). The percentages at each level were as follows: 1 mm from the working length, 14.1% +/- 19% for group A and 5% +/- 7.5% for group B; 3 mm from working length, 1.8% +/- 5.4% for group A and 3.9% +/- 6.9% for group B; and 5 mm from working length, 3.1% +/- 7.7% for group A and 2.6% +/- 7.3% for group B. In group A, there was significantly more debris in the 1-mm section than in the 3- or 5-mm sections. In group B, the differences between levels were not significant. There was no significant difference in the amount of debris remaining in the apical 5 mm of canals when comparing the handpiece-mounted irrigation device to irrigation with a syringe and needle. The average times for instrumentation in group A (needle irrigation) and group B (Quantec-E irrigation system) were 8.7 +/- 2.7 min and 6.5 +/- 1.9 min, respectively. Group B was associated with statistically significant shorter instrumentation time (p < 0.0005). An average of 12.5 +/- 4.9 ml of irrigant was used in group A and 17.3 +/- 4.8 ml in group B. The difference was statistically significant (p < 0.0005).