IADR Abstract Archives
Effect of Internal-Glazed on Bond Strength of Resin Cement to Zirconia Crown
Objectives: Reduced bond strength of resin cement normally occurs when being applied with zirconia restorations. In low-fusing silica-based ceramic (glazing technique), the glassy matrix is selectively removed by hydrofluoric acid (HF) etching which increasing micromechanically retentive area. Consequently, it is possible to improve better retention for resin cement. The objective of this study is to evaluate effect of internal-glazed on tensile bond strength (TBS) of RelyX Ultimate resin cement to Ceramill ZI zirconia crown.
Methods: Twenty-four human upper premolar teeth were obtained. The teeth were prepared to create a flat occlusal surface, 16°total occlusal convergence, 0.8mm deep chamfer margin and 4mm height. Each abutment was scanned and designed to fabricate 2mm-thickness crown. Subsequently, zirconia discs were milled and sintered. All specimens were divided randomly into two groups as internal-glazed (n=12) and control groups (n=12). In internal-glazed group was glazed by VITA AKZENT Plus glazing spray on internal surface of crowns. The glazed surfaces were etched (10% HF, 20seconds), rinsed, cleaned and air-dried. All specimens were applied Singlebond Universal, cemented and applied 50N during cementation. Then, they were kept in distilled water (37°C, 24hours). TBS were performed by using universal testing machine at a constant crosshead speed of 1 mm/min. T-test was used for statistic analysis.
Results: The means TBS of internal-glazed and control groups are 2.83±3.701MPa and 3.68±2.604MPa, but were not significantly difference. All failures occurred in the adhesion zone.
Conclusions: Within the limitations of this study, the use of internal-glazed did not increase bond strength of resin cement to zirconia crown.
Methods: Twenty-four human upper premolar teeth were obtained. The teeth were prepared to create a flat occlusal surface, 16°total occlusal convergence, 0.8mm deep chamfer margin and 4mm height. Each abutment was scanned and designed to fabricate 2mm-thickness crown. Subsequently, zirconia discs were milled and sintered. All specimens were divided randomly into two groups as internal-glazed (n=12) and control groups (n=12). In internal-glazed group was glazed by VITA AKZENT Plus glazing spray on internal surface of crowns. The glazed surfaces were etched (10% HF, 20seconds), rinsed, cleaned and air-dried. All specimens were applied Singlebond Universal, cemented and applied 50N during cementation. Then, they were kept in distilled water (37°C, 24hours). TBS were performed by using universal testing machine at a constant crosshead speed of 1 mm/min. T-test was used for statistic analysis.
Results: The means TBS of internal-glazed and control groups are 2.83±3.701MPa and 3.68±2.604MPa, but were not significantly difference. All failures occurred in the adhesion zone.
Conclusions: Within the limitations of this study, the use of internal-glazed did not increase bond strength of resin cement to zirconia crown.