Apical microleakage of root-end cavities prepared by Er, Cr: YSGG laser

The effect of ultrasonically activated irrigation and laser based root canal irrigation methods on debris removal

PURPOSE

To test the efficacy of debris removal of 5 in vitro irrigation protocols: conventional irrigation, irrigation activated by ultrasound, Er:YAG laser with photon-induced photoacoustic streaming (PIPS) tip, and 2 diode laser techniques.

METHODS

The root canals of 75 extracted human canine teeth were enlarged and bisected longitudinally. Standardized grooves were prepared 2-6 mm from the root apex and filled with 0.5 mm of dentine debris. The teeth were reassembled and irrigated using 1 of the following techniques (n = 15/technique): (1) conventional irrigation, (2) diode laser irrigation - tip placed 2 mm from working length, (3) diode laser irrigation - tip placed at root canal orifice, (4) Er:YAG laser - PIPS, and (5) ultrasonically activated irrigation. The root segments were disassembled, and the amount of remaining debris was evaluated by 3 examiners under a stereomicroscope at ×20 magnification using a 4-grade scoring system. The data were statistically analyzed using Kruskal-Wallis and Dunn's multiple comparison tests, with a 95% confidence level (p = 0.05). Cohen's kappa test was used to evaluate inter-observer and intra-observer agreement.

RESULTS

Ultrasonically activated irrigation removed significantly more dentinal debris than conventional irrigation (p = 0.016), but there were no significant differences between the other groups.

CONCLUSIONS

Ultrasonically activated irrigation was more effective than conventional irrigation in the removal of apically placed dentine debris.

Effect of Er,Cr:YSGG laser irradiation on apical sealing ability of calcium silicatecontaining endodontic materials in root-end cavities

The aim of this research was to evaluate the apical sealing abilities of 60 root-end cavities filled with mineral trioxide aggregate (MTA) and iRoot BP cements after treated with either 17% EDTA solution or Er,Cr:YSGG laser irradiation. After the filling procedure, apical leakage quantity was measured at 4 weeks using a fluid filtration method. One root from each group was processed for scanning electron microscopy and energy dispersive X-ray spectroscopy analyses. Both EDTA/MTA and laser irradiation/MTA combinations showed significantly lower microleakage than EDTA/iRoot BP and laser irradiation/iRoot BP combinations (p<0.05). Between groups of the same filling material, there were no significant differences among specimens treated with EDTA or laser (p>0.05). Both MTA and iRoot-BP demonstrated tag-like structures within the dentinal tubules when used in conjunction with EDTA.