Influence of Titanium/Triceram and Zirconia/Triceram veneering thickness on biaxial bond strength

Introduction: Due to a similar coefficient of thermal expansion of the dental materials titanium and zirconia the veneering porcelain Triceram is recommended to be used for both substrate materials. The aim of the study was to evaluate the influence of 3 different veneering thicknesses on the resulting biaxial bond strength to titanium and zirconia. Material & Methods: From each material 30 discs with a diameter of 12 mm and a thickness of 0.8 mm were veneered with a thickness of 1.0, 1.5 and 2.0 mm, respectively, using a special positioning device. With each specimen 5 firings (opaque 1 and 2, dentin 1 and 2, glaze; furnace: Dekema) were done according to the manufacturer's instructions. The biaxial bond strength test was performed on the basis of ISO 6872 using a universal testing machine (Zwick Z010, Ulm; software testexpert V12) with a crosshead speed of 1 mm/min. With all samples the veneered part was put on the balls and the biaxial bond strength for bilayered piston-on-three-ball discs was calculated [1] and, the Weibull modulus was determined. Results: The biaxial bond strength for 1.0, 1.5 and 2.0 mm veneering thickness was 193±43, 205±46 and 170±25 MPa for titanium/Triceram and, 187±46, 155±43 and 132±44 MPa for zirconia/Triceram. The Weibull modulus ranged from 5.5, 5.1 to 8.1 for titanium and, 5.0, 4.1 to 2.9 for zirconia. Conclusion: The veneering porcelain Triceram revealed higher bond strength characteristics with titanium compared to zirconia. Similar bond strength values could be found with 1.0 and 1.5 mm porcelain thickness, whereas 2.0 mm showed significantly lower values. Parole chiave: Titanium, Zirconia, Bilayer, Biaxial Bond strength