STATEMENT OF PROBLEM: The resistance to fracture of ceramic restorations depends on adequate bonding to tooth structure. The dental substrate and the types of resin luting agents used are believed to produce variability in adhesive properties. PURPOSE: The purpose of this study was to evaluate the tensile bond strength of 4 resin luting agents to bovine enamel and dentin. MATERIAL AND METHODS: Forty bovine incisors were embedded in acrylic resin and ground horizontally with water-cooled silicon carbide paper to expose enamel (20 teeth) and dentin at the enamel/dentin junction (20 teeth). Ten standard cone-shaped specimens with a 3-mm diameter base were prepared for each of the following resin cements: Resin Cement, Rely X ARC, Nexus, and Enforce. Five specimens of each material were bonded to enamel and the other 5 to dentin with these resin luting agents and their respective adhesive systems, according to the manufacturers' directions. After 7 days of storage in distilled water at 37 degrees C, specimens were subjected to tensile forces in a universal testing machine at a crosshead speed of 0.5 mm/min until fracture. Bond strength data were analyzed with analysis of variance for substrate and material. Means were compared with Tukey's test at the 0.05 level of significance. RESULTS: Analysis of variance disclosed that both substrate (P<.001) and material (P<.05) demonstrated statistically significant differences, but their interaction was not significant. The bond strengths (MPa) obtained for Resin Cement (11.5 +/- 3.0), Rely X ARC (11.4 +/- 3.1), Nexus (10.0 +/- 1.4), and Enforce (11.8 +/- 2.8) were statistically the same for enamel. For dentin, bond strengths (MPa) for Rely X ARC (9.6 +/- 1.8), Resin Cement (9.3 +/- 0.9), and Enforce (7.8 +/- 2.9) were significantly higher than for Nexus (3.5 +/- 0.8). Significantly higher bond strengths (MPa) were also observed for enamel (11.2 +/- 2.5) than dentin (7.5 +/- 1.6). CONCLUSION: Within the limitations of this study, tensile bond strengths of resin luting agents to enamel were higher than those to dentin, and the bond strength values of Nexus to dentin were significantly lower (P<.05) than the other cements tested.
STATEMENT OF PROBLEM: The resistance to fracture of ceramic restorations depends on adequate bonding to tooth structure. The dental substrate and the types of resin luting agents used are believed to produce variability in adhesive properties. PURPOSE: The purpose of this study was to evaluate the tensile bond strength of 4 resin luting agents to bovine enamel and dentin. MATERIAL AND METHODS: Forty bovine incisors were embedded in acrylic resin and ground horizontally with water-cooled silicon carbide paper to expose enamel (20 teeth) and dentin at the enamel/dentin junction (20 teeth). Ten standard cone-shaped specimens with a 3-mm diameter base were prepared for each of the following resin cements: Resin Cement, Rely X ARC, Nexus, and Enforce. Five specimens of each material were bonded to enamel and the other 5 to dentin with these resin luting agents and their respective adhesive systems, according to the manufacturers' directions. After 7 days of storage in distilled water at 37 degrees C, specimens were subjected to tensile forces in a universal testing machine at a crosshead speed of 0.5 mm/min until fracture. Bond strength data were analyzed with analysis of variance for substrate and material. Means were compared with Tukey's test at the 0.05 level of significance. RESULTS: Analysis of variance disclosed that both substrate (P<.001) and material (P<.05) demonstrated statistically significant differences, but their interaction was not significant. The bond strengths (MPa) obtained for Resin Cement (11.5 +/- 3.0), Rely X ARC (11.4 +/- 3.1), Nexus (10.0 +/- 1.4), and Enforce (11.8 +/- 2.8) were statistically the same for enamel. For dentin, bond strengths (MPa) for Rely X ARC (9.6 +/- 1.8), Resin Cement (9.3 +/- 0.9), and Enforce (7.8 +/- 2.9) were significantly higher than for Nexus (3.5 +/- 0.8). Significantly higher bond strengths (MPa) were also observed for enamel (11.2 +/- 2.5) than dentin (7.5 +/- 1.6). CONCLUSION: Within the limitations of this study, tensile bond strengths of resin luting agents to enamel were higher than those to dentin, and the bond strength values of Nexus to dentin were significantly lower (P<.05) than the other cements tested.
Authors: Eduardo Diogo Gurgel-Filho; Felipe Coelho Lima; Vicente de Paula Aragão Saboia; Tauby de Souza Coutinho-Filho; Aline de Almeida Neves; Emmanuel João Nogueira Leal da Silva Journal: Restor Dent Endod Date: 2014-08-20