Effectiveness of laser-assisted irrigation and passive ultrasonic irrigation techniques on smear layer removal in middle and apical thirds

The purpose of this study was to investigate the evaluation of laser-assisted irrigation (LAI) on the removal of the smear layer as compared to passive ultrasonic irrigation (PUI). Forty-eight single-rooted, upper-central incisor teeth were selected and prepared with ProTaper rotary instruments up to size #40 (F4) at the working lengths. Specimens were divided into four groups, as follows: (a) PUI with 5 mL of 2.5% NaOCl for 60 s; (b) PUI with 2.5 mL of 17% EDTA and 2.5 mL of 2.5% NaOCl each for 30 s; (c) LAI with 5 mL of 2.5% NaOCl for 60 s; and (d) LAI with 2.5 mL of 17% EDTA and 2.5 mL of 2.5% NaOCl each for 30 s. In the PUI groups, the ultrasonically activated file was inserted 1 mm short of the working length, but in the LAI groups, the fiber tip was applied into the pulp chamber. LAI in the pulp chamber with the combination of 17% EDTA and 2.5% NaOCl removed more of the smear layer than the other groups (p < 0.018). LAI in the pulp chamber with the combination of 2.5% NaOCl and 17% EDTA better removed the smear layer than LAI applied similarly but without EDTA or PUI with the same NaOCl and EDTA combinations using an ultrasonically activated file inserted 1 mm short of the working length.

Efficacy of various irrigation protocols on the removal of triple antibiotic paste

AIM

To compare the efficacy of irrigation protocols on the removal of triple antibiotic paste (metronidazole, ciprofloxacin and minocycline) (TAP) from artificial grooves in root canals.

METHODOLOGY

Root canals in 72 extracted single-rooted teeth were prepared using ProTaper rotary instruments up to size F5. The roots were split longitudinally and a standardized groove was prepared in the apical part of one segment. TAP was placed in the grooves, and the root halves were reassembled. The roots were randomly divided into six experimental groups according to the irrigation protocol used: distilled water, 1% NaOCl, 2.5% NaOCl, 100% ethanol, 17% EDTA and passive ultrasonic irrigation (PUI) with 1% NaOCl. The root segments were disassembled, and the amount of TAP remaining was evaluated under a stereomicroscope at 20× magnification using a four-grade scoring system. The data were evaluated statistically using Kruskal-Wallis and Mann-Whitney U-tests with a 95% confidence level (P = 0.05).

RESULTS

There were significant differences amongst the groups (P < 0.001). Passive ultrasonic irrigation (PUI) with 1% NaOCl removed significantly more TAP than the other irrigating solutions (P < 0.05). Distilled water, 1% NaOCl, ethanol and EDTA were associated with significantly more remaining TAP.

CONCLUSIONS

PUI with 1% NaOCl was more effective in removing TAP from artificial grooves in root canals than other irrigating solutions without ultrasonic agitation. It was not possible completely to remove TAP from root canals.