Bonding strength of universal adhesives to Er,Cr:YSGG Laser-Irradiated Dentin.

OBJECTIVES: Universal adhesives have been recently introduced for use as self-etch or etch-and-rinse adhesives depending on the dental substrate and clinical condition. However, their bonding effectiveness to laser-irradiated dentin is still not well known. Therefore, the aim of this study was to compare the shear bond strength (SBS) of two universal adhesives (Single Bond Universal, Nova Compo-B Plus) applied following laser-etching with SBS of the same adhesives applied in self-etch and acid-etch modes, respectively.

MATERIALS AND METHODS: Sixty bovine incisors were used to obtain the flattened dentin surfaces. Specimens were divided into two groups according to universal adhesives. Each universal adhesive was applied with one of the following modes, self-etch, acid-etch, or laser-etch (n = 10). Er,Cr:YSGG laser was used for laser-etching with 1.5 W-20 Hz parameters. After adhesive applications and composite buildups, SBS was determined after storage in water for 24 h using a universal testing machine with a crosshead speed of 0.5 mm/min. Failure modes were evaluated using a stereomicroscope. Data were analyzed using two-way of analyses of variances (ANOVA) (P = 0.05).

RESULTS: Two-way ANOVA revealed that adhesive had no effect on SBS (P > 0.05), but application mode significantly influenced SBS (P < 0.001). Laser-etch significantly increased SBS for NCP when compared to self-etch mode, whereas laser-etch provided similar SBS with self-etch mode for SBU.

CONCLUSIONS: The influence of different application modes on dentin bond strength of universal adhesives was dependent on the adhesive material.

CLINICAL SIGNIFICANCE: For universal adhesives, laser etching may provide some benefits on bonds strength but this would depend on product.