Effects of Diode Laser and MTAD (TM) on the Push-Out Bond Strength of Mineral Trioxide Aggregate-Dentin Interface

Abstract

Objective: The aim of this in vitro study was to evaluate the effects of diode laser, MTAD (TM) and laser plus MTAD on the push-out bond strength of mineral trioxide aggregate (MTA)-dentin. Background data: MTA has been used widely, especially in root canal therapies (RCT); however, the effect of different final treatments during RCT has been questioned regarding the retention characteristic of this cement-based material. Materials and methods: Forty single-rooted human teeth were prepared into dentin slices and drilled to form canal spaces. Samples were divided into four groups of 10 in each (n = 10). In groups A and B, diode laser irradiations were performed, and then MTA was placed inside the canal spaces and incubated at 37 degrees C for 7 days. After incubation, dentin slices in groups B and C were immersed in Biopure MTAD, and the last group served as control without any treatment. The push-out bond strengths were then measured by using a universal testing machine. Results: The mean +/- standard deviations of push-out bond strength were 6.74 +/- 0.48, 5.95 +/- 0.40, 6.86 +/- 0.66, and 7.88 +/- 0.37 for groups A (laser), B (laser plus MTAD), C (MTAD) and D (control), respectively. One-way analysis of variance (ANOVA) test revealed significant differences among the groups (p < 0.0001). Tukey's test did not show any significant difference between groups A and C (p = 0.93). However, these differences were significant between groups A and B (p = 0.006) and between groups B and C (p = 0.001). Conclusions: The results of this study indicated that either diode laser or MTAD can lower the bond strength of MTA-dentin, and that diode laser irradiations plus MTAD might affect MTA bond to dentin negatively.