Effect of ER: YAG Laser Treatment on the Bond Strength of Self-adhesive Resin Cements on Contaminated and Non-contaminated Dentin Surface

Abstract

Background: Nowadays, lasers are used to modify the surface of dentin and enamel and improve the surface bond with resin cement while contamination weakens this bond. Objective: This study aimed to evaluate the effect of different contamination types on the microshear bond strength (μSBS) of two self-adhesive resin cements to dentin with/without laser treatment. Methods: One-hundred and twenty molar teeth were prepared and randomly divided into three groups: blood, saliva, and control. In the blood group, blood was applied to the samples for 10 seconds; in the saliva group, saliva was applied to the samples for 10 seconds; and in the control group, distilled water was applied to the samples. Each group was further divided into two subgroups; in one, the Er: YAG laser was applied to samples for 5 seconds, and in the other, no laser treatment was performed. Next, TheraCem and Embrace WetBond cements were placed on each sample. μSBS was measured using a universal testing machine. Results: In Embrace WetBond, μSBS was not affected by contamination type regardless of laser treatment. In TheraCem, μSBS was not affected by contamination type when the laser was not used. In contrast, with laser treatment, blood contamination decreased μSBS compared to control and saliva. After laser treatment in the presence of blood, μSBS of Embrace WetBond was significantly higher than that of TheraCem, while without laser treatment, no significant difference was observed between the two cements. Conclusion: Dentin conditioning with an erbium laser can increase the cement bond strength to dentin if proper isolation is achievable. If proper isolation cannot be obtained, dentin conditioning with erbium laser followed by application of Embrace WetBond cement can increase the microshear bond strength of cement to dentin.