Factors Affecting the Shear Bond Strength of Bonded Composite Inlays

Purpose: This article analyzes the influence of different pretreatments on the bond strength between inlays and the resin cement of three different composite inlay systems: Z-100, Targis, and Art Glass. Materials and Methods: Four separate treatments of the composite-bonding agent interface were investigated: (1) untreated surface, (2) grinding, (3) sandblasting, and (4) sandblasting followed by silane treatment. Surface topography, roughness, and shear bond strength were evaluated using digital scanning electron microscopy, confocal laser scanning profilometry, and a Lloyd LRX equipped for shear bond testing, respectively. Results: The bond strength is presented both with respect to composite surface pretreatment and with respect to different composite inlay systems. Independent of the composite inlay system, the sandblasted and silane-treated surface was found to give the highest bond strength values, followed by the sandblasted and ground surfaces. The untreated surface showed the lowest bond strength. For pretreated surfaces, Targis showed the highest (P 0.05) bond strength values, followed by Art Glass and Z-100. This distribution, however, was reversed for the untreated interface, where Z- 100 showed the highest bonding strength (P 0.05). Conclusion: Surface pretreatment and roughness as well as the inlay material have an impact on the bond strength and the retention of composite inlays.