Efficacy of smear layer removal at the root tip by using ethylenediaminetetraacetic acid and erbium, chromium: yttrium, scandium, gallium garnet laser.

摘要

INTRODUCTION: The purpose of this study was to compare the efficacy of laser-driven irrigation in removing the smear layer and debriding the apical region of the root canal (the root tip) with that of ultrasonic irrigation. METHODS: Forty extracted human teeth with straight single roots were randomized into 4 groups (n = 10). The specimens were shaped by using hand instruments up to a size 30/.02 file (Control, Laser 1, and Laser 2 groups) or a size 20/.02 file (Laser 3 group). During instrumentation, each canal was irrigated with 3% NaOCl and 17% ethylenediaminetetraacetic acid alternately between the use of successive files. The 4 groups of 10 teeth were processed as follows. In the Control group, teeth were irrigated with 17% ethylenediaminetetraacetic acid, and the irrigant was activated with an ultrasonic device for 60 seconds. In the Laser 1 and Laser 3 groups, the irrigant was activated with the laser for 60 seconds. In the Laser 2 group, the irrigant was activated with the laser for 30 seconds. RESULTS: There were significant differences between the smear layer and debris scores for the Laser 1 group and those for the Control (P < .001), Laser 2 (P = .002), and Laser 3 groups (P = .012 and P = .013, respectively). Completely clean root canals were found in the Laser 1 group. CONCLUSIONS: Use of a laser with a plain fiber tip, which produces cavitation in the irrigant, has potential as an improved alternative method for removing of the smear layer from the apical region of a straight root canal.