In vitro evaluation of the push-out bond strength of the epoxy resin-based root canal sealer to root dentin irradiated with double-wavelength lasers

Abstract

The influence of dual-wavelength lasers Er,Cr:YSGG 2780 nm and diode 940 nm on bond strength of the epoxy resin-based sealer (AH Plus) to the root dentin was evaluated. Thirty-three extracted human mandibular and maxillary straight and single-rooted teeth were sectioned at the cementoenamel junction perpendicular to the long axis. All the teeth were endodontically prepared and cut with thin disc 1.1 mm thickness transversally to the long axis. The teeth were randomly divided into three groups (n = 40). In group 1, 1 ml of NaOCl (5.25%) was used between every drill exchange for irradiating the canals. Group 2 was irradiated with EDTA (17%) and NaOCl in order to remove the smear layer from the canals. In group 3, the canals irradiated with 2780 nm Er,Cr:YSGG laser using radial firing tips and 940 nm diode laser. One root from every group was selected for scanning electron microscopy (SEM) analysis. Statistical analysis was performed using the Shapiro–Wilk test and one-way ANOVA test. Statistically significant differences were observed in group 2 (EDTA Plus NaOCl) compared with the two other groups (p < 0.001). There were no significant differences between the laser and control group (p = 0.987). The mode of failure in all groups was the cohesion failure indicating the failure within the sealer. SEM examination confirmed the presence of a thick smear layer in group 1 and open dentinal orifices in groups 2 and 3. In spite of removing the smear layer, the dual-wavelength laser has no effect on the push-out bond strength of AH Plus sealer.