Shear bond strength of resin composite veneering material to Ni-Cr alloy with two conditioners

Abstract

This study evaluated the effects of two metal conditioners on the bond strength of resin composite with a base metal alloy. Twenty alloy discs were cast with Ni-Cr alloy (Vera Bond II), ground with 320, and 600 grit sandpaper, respectively and sandblasted with 100 µm alumine during 10 seconds at distance of 20 mm and divided into 2 groups of 10 specimens: in group I, the bonding surfaces of the metal were treated with Metal Photo Primer. In group II, the Agent União (EPO, Brazil) was applied on the metal surface and them light polimerized with a metallic steam bulb unit or 4 min. (Ultrasystem, Brasil). Solidex opaque and dntin composites were placed onto the treated metal surface and then light-polymerized acording to manufacture´s instructiuon. All specimens were stored in distilled water at 37C for 24 hours. Additionally specimens at crosshead speed of 0,5 mm/min. The failure types were analized by using both optical stereomicroscope at 40X and scanning electron microscope. Data were analyzed by Student´s test (P<001). The results showed that the shear bond strengths of group II (11.72 MPa) was significantly more than group I (7.6 MPa). For group II failures were a mixture of both cohesive and adhesive patterns, and mainly adhesive in nature for group II. this in vitro study indicated that the new metal conditiones showed significantly higher shear bond strenght than the Metal Photo Primer.