The effect of metal surface treatment on bond strength interface between metal/cement

Resumo

Objective: This study evaluated the hypothesis that different treatments of surface upon three metal alloys for metal ceramic dental prostheses (Gold; Nickel-Chromium; Titanium) do not Influence the values of bond strength with resin cement. Material and Methods: Twenty blocks, 5x5x5 mm, of each alloy were divided into two subgroups (n = 10) according to surface treatments: 1 (Primer): sandblasting with aluminum oxide particles 110 µm (Al₂O₃) + Alloy Primer (Kuraray); 2 (Cojet): sandblasting with silica oxide particles with Cojet-Sand + Silane ESPE-Sil. The conditioned blocks of each group were cemented, with Panavia F, to resin blocks under constant load of 750 g/10 min. The sets were cut to obtain 4 samples with dimensions of 10x1x1 mm per block (n = 10) and the adhesive surface with approximately 1 mm². The microtensile test was done in the universal testing machine at 1 mm/min crosshead speed. The values of bond strength and standard deviation (MPa) were: Au P: 7.33 ± 1.93^d; Au C: 13.35 ± 2.18^c; NiCr P: 23.56 ± 6.5^b; NiCr C: 42.6 ± 5.84^a; Ti P: 26.17 ± 1.94^b; Ti C: 44.30 ± 2.3^a. Data were analyzed by variance test (ANOVA) and Tukey’s test, p < 0.05. Results: The results indicated that the conditioning with treatment 2 increased the bond strength between the resin cement and alloys. The lowest bond strengths values were obtained with gold alloy, regardless the surface treatment. Conclusion: The results denied the hypothesis that the metallic alloys surface treatments do not alter the bond strengths values.