Evaluation of flexural strength of titanium ceramic bonding with different surface treatment modalities

Objectives: The aims of the present study were to investigate the following: (1) the effects of surface treatment with hydro fluoric (HF), airborne particle abrasion with alumina AL2O3, and sputter coating with zirconia ZrO2 on the bond strength of porcelain to titanium. (2) To compare the bond strength of low fusing veneering ceramics and pressed ceramic to titanium.;Methods: Sixty specimens of commercially pure titanium strips (ASTM grade IV, Titanium Industries, Aurora, IL) were prepared to the dimensions 25.0mmx3.0mmx0.5mm required by ISO 9693.The specimens were divided into six groups (n=10). The first and second groups were prepared with air particle abrasion using aluminum oxide. The third and fourth groups were prepared by hydrofluoric acid etching. The fifth and sixth groups were prepared by zirconium oxide magnetron sputtering. Then for the first, third, and fifth groups an 8x3x1 mm porcelain strip (Triceram, Dentaurum) was centered on each of the metal strips and sintered as described below. For the second, fourth, and sixth groups an 8x3x1 mm porcelain strip (Emax press, Ivoclare vivadent) was centered on each of the metal strips and pressed as described below. All specimens were subjected to a three-point bending test at a crosshead speed of 1.5mm/min-1 until debonding occurred, using a universal testing machine. Fractured specimens were carbon coated and examined with scanning electron microscope for fractographic analysis. Data were statistically analyzed using two way ANOVA and the Tukey HSD test was used for multiple comparisons (alpha=.05) using statistical software SPSS 16.0.;Results: The mean debonding strength values in MPa for each group were: 31.06 (SD 3.78) for the alumina air abraded Ti-Triceram group, 37.99 (SD 3.33) for the alumina air abraded Ti-Emax press group, 22.85 (SD 5.35) for the HF treated Ti-Triceram group, 36.18 (SD 4.55) for the HF treated Ti-Emax press group, 35.99 (SD 4.86) for the zirconia sputtered Ti-Triceram group, and 49.10 (SD 4.77) for the zirconia sputtered Ti-Emax press group. Significant differences among the groups were detected by two-way ANOVA (p=0.001). Post-hoc analysis using Tukey test revealed significant differences between all groups (p=0.001).;Conclusions: Within the limitations of this investigation and for the materials used in this study, the following conclusions were made: 1. Surface treatment using ZrO2 sputtering significantly reduced the oxide layer and enhanced the bond between commercially pure titanium to low-fusing porcelain. 2. The use of HF surface treatment significantly reduced the bond strength between commercially pure titanium to low-fusing porcelain. 3. The Ti-Emax press porcelain system showed significantly higher bond strength values compared to Ti-Triceram porcelain system.