The influence of SiO2 and SiO2-TiO2 intermediate coatings on bond strength of titanium and Ti6A14V alloy to dental porcelain

Objectives. The purpose of this study was to evaluate the bond strength of commercially pure CPTi and Ti6A14V alloy with SiO2 and SiO2-TiO2 intermediate coatings to Triceram low-fusing dental porcelain. Methods. The multilayered systems were characterized from the standpoint of microstructure analysis (SEM), the mode of failure, the nature of bonding and the influence of intermediate coatings on the improvement of bond strength. The SiO2 and SiO2-TiO2 intermediate coatings were applied on the substrate materials by the sol-gel dipping technique. The metal-ceramic bond strength was investigated according to ISO 9693 standards using the three-point flexure bond test. Results. Statistically significant higher bond strength of the metal-porcelain for Ti6A14V alloy (28.24 MPa), Ti6A14V/SiO2 (32.17 MPa) and Ti6A14V/SiO2-TiO2 (36.09 MPa) was noted in comparison to CPTi (23.04 MPa), CPTi/SiO2 (27.98 MPa) and CPTi/SiO2-TiO2 (28.84 MPa), respectively. The nature of metal-intermediate coating-porcelain bonding was both mechanical and chemical. The failure in all systems was cohesive and adhesive, mainly adhesive. Significance. The application of SiO2 and SiO2-TiO2 intermediate coatings, produced by the sol-gel method, to both CPTi and Ti6A14V alloy significantly improves the bond strength of metal-porcelain systems in comparison to the metal substrate only after sandblasting, and may have clinical use. (C) 2009 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.