Improving Bond Strength And Thermal Behaviour Of New Sodalite Infiltrate Ceramic Core Materials

The mismatch in coefficient of thermal expansion (CTE) between the veneered porcelain and the ceramic core has been primarily identified as the cause of core/veneer chipping in all-ceramic restorations. This study aimed to evaluate the effect of sodalite infiltration on the CTE behaviour and bond strength of different all-ceramic prostheses. Materials and Methods: The experimental groups were synthesised sodalite-infiltrated alumina (IA-SOD) and synthesised sodalite-infiltrated zirconia-toughened alumina (ZTA) (IZ-SOD), while the control groups were glassinfiltrated alumina (IA-glass) and glass-infiltrated ZTA (IZ-glass). Forty cylindrical-shaped samples (5mm diameter; 10mm height) were tested for CTE. Another forty disc-shaped samples (12mm diameter; 1.2±0.2mm thick) and veneered with cylinder-shaped low-fusing porcelain (2mm high; 2mm diameter) were prepared for shear bond strength test. SEM, stereo microscope and AFM were used to investigate the structural characteristics of samples at the fracture surface. Results: The CTE values for both IZ-SOD and IA-SOD were 8.62 x 10-6 K-1 and 8.37 x 10-6 K-1 respectively, which were statistically higher than IZ-glass and IA-glass (8.08 x 10-6 K-1 and 7.63 x 10-6 K-1 , respectively) (p0.05). Conclusion(s): The higher CTE mismatch and bond strength of the newly developed SOD-infiltrated samples than did the commercial glassinfiltrated samples could thus make them suitable for all-ceramic dental prostheses.