Effect of Light Intensity on Shear Bond Strength of Adhesive Resin Cements to Ceramics

Abstract

This study examined the effect of light intensities on the shear bond strengths of adhesive resin cements to ceramic blocks. Two commercially available dual-cured adhesive resin cements and a CAD/CAM ceramic plate were used. Each adhesive resin cement bonded to the ceramic plate at two different thicknesses (1 or 3mm) using light curing unit at two different light intensities (300 or 800mW/cm²). Light was irradiated through the ceramic plate to cure the cement. The shear bond strengths of cements to ceramics were measured at 5, 10, 30, 60 minutes or 24 hours after the start of mixing using the universal testing machine. The shear bond strength of cements to ceramics at 800mW/cm² was significantly greater than 300mW/cm² for 5 minutes (p＜0.05). Shear bond strength of cements to ceramics at 1mm was significantly greater than at 3mm for 5 minutes except for P, with B3 shade at 300mW/cm² (p＜0.05). Light intensity could be a factor affecting the bond strength of dual-cured adhesive resin cements to ceramic at the initial setting stage of resin cements.