Smear layer is a negative factor which prevents adhesion of the filling material to the dentinal walls. Recent advances in dental research have incorporated lasers as a potential adjunct in root canal treatment by removing the smear layer before filling the root canal system, enhancing the adhesion of sealers to dentin and improving the sealing ability.

To evaluate the microtensile bond strength of AH-Plus resin-based sealer to dentin after treatment with 980 nm diode and 1,064 nm neodymium-doped:yttrium aluminum garnet (Nd:YAG) laser in vitro.

Thirty specimens prepared for three groups namely group I (control), group II (980 nm diode–lased specimens) and group III (Nd:YAG–lased specimens). One tooth from each group was observed under scanning electron microscope for evaluation of intracanal root dentin morphology. Remaining specimens were used for making microsections by hard tissue microtome. Specimens for groups II and III were lased with 980 nm diode and 1,064 nm Nd:YAG laser. AH Plus sealer was applied onto specimens and mounted onto Instron universal testing machine for microtensile bond strength testing. Results were subjected to statistical analysis using one-way analysis of variance (ANOVA) and Tukey's test.

Group III Nd:YAG had maximum mean microtensile bond strength values (11.558 ± 0.869), followed by group II diode (9.073 ± 0.468) and group I control (6.05 ± 0.036). Statistically significant differences were seen among all the groups. SEM analysis shows removal of smear layer in both groups II and III.

Both Nd:YAG and diode laser were more effective than control group in improving the microtensile bond strength of AH Plus sealer to dentin.

Lasers have the potential to increase the adhesiveness of root canal sealer to dentin surface, thereby improving the quality of root canal obturation.

Maneesha D, Anil KG, Sindhu R, Surendranath G, Deepak S. An in vitro Evaluation of Microtensile Bond Strength of Resin-based Sealer with Dentin Treated with Diode and Nd:YAG Laser. J Contemp Dent Pract 2013;14(2): 183-187.