Bond between gold alloy and ceramic in relation to the thickness of the oxide layer

BACKGROUND: The chemical bonding between metal and ceramic is aided by non-precious metal atoms and their oxides present on the metal surface. Aim of the study was to correlate metal-ceramic bonding with thickness oxide layer on a new gold alloy. METHODS: Thirty-two specimens were constructed in gold alloy and ceramic, with the aim of evaluating the degree (using shear test) and quality (using optical microscope) of bonding resistance between these materials, in relation to the thicknesses of the oxide layer produced on the metallic parts by means of different thermal procedures. RESULTS: Bond strength was practically the same with different thicknesses of the oxide layer. A slight reduction in the degree of bonding was observed in the non-oxidised models. CONCLUSIONS: For the gold-alloy here tested, the oxide layer seems to be not influent in the chemical metal-ceramic bond strengt