Effect of surface treatment on porcelain bond strength to titanium

OBJECTIVES: The aim of this study was to evaluate the bond strength of a low fusing veneering porcelain fired on Titanium grade V with different surface treatments. MATERIALS & METHODS: One hundred and twenty bars of Titanium grade V (25±1x 3±0.5x 0.5±0.05mm) were divided randomly into twelve groups: group 1 no surface treatment, group 2 Gold sputter coating, group 3 TiN sputter coating, group 4 Sandblasting Al2O3 125μm, group 5 Sandblasting Al2O3 180μm, group 6 Sandblasting Al2O3 250μm, group 7 Sandblasting Al2O3 125μm then gold sputter coating, group 8 Sandblasting Al2O3 180μm then gold sputter coating, group 9 Sandblasting Al2O3 250μm then gold sputter coating, group 10 Sandblasting Al2O3 125μm then TiN sputter coating, group 11 Sandblasting Al2O3 180μm then TiN sputter coating, group 12 Sandblasting Al2O3 250μm then TiN sputter coating. Vita Titankeramik porcelain was applied for all groups and built up manually with dimensions limited to 8x3x1mm and fired on Ti bars following the manufacturer’s instructions and ISO 9693 recommendations, and tested for bond strength by Schwickerath crack initiation test (ISO 9693) using an Instron universal testing machine (Model: 5566A). The mode of failure and bond interface were evaluated by SEM / EDS. RESULTS: The mean bond strength values of groups 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 were 2.31MPa (±0.2), 24.3MPa (±0.78), 46.94MPa (±1.29), 6.18MPa (±0.98), 9.46MPa (±1.08), 15.14MPa (±0.74), 24.84MPa (±1.73), 36.24MPa (±1.43), 41.49MPa (±2.13), 49.45MPa (±0.96), 69.36MPa (±0.96), 94.45MPa (±1.51), respectively. Two-way ANOVA with Tukey multiple comparisons test was performed to determine the groups that are statistically different. All tested groups (1-12) showed statistically significant difference except groups 2, and 7, P< 0.05. CONCLUSIONS: Within the limitations of this study, the following conclusions can be drawn: 1- Surface finish significantly affects the bond strength of low fusing porcelain to Ti grade V. 2- Larger Al2O3 particle size corresponded to higher bond strengths. 3- Sandblasting in combination with Au or TiN coatings produced the highest bond strength values. 4- Groups 1, 4, 5, & 6 showed Adhesive failure at the ceramic – metal interface; for groups 3, 10, 11, & 12 were found to be Cohesive failure within the porcelain layers; and for groups 2, 7, 8, & 9 were found to be mixed Adhesive / Cohesive failure.2018-09-28T00:00:00