IADR Abstract Archives
Does Etching of Glass-Ceramics Create an FGL? Initial Studies
Objectives: Etching and bonding improve glass based ceramic crown performance either from removing ceramic surface damage, creating a functionally graded layer (FGL), or both. This preliminary study evaluated etching depth and cement modulus on bonded ceramic fatigue reliability
Methods: Flat trilayer (ceramic-e.max CAD/cement/composite-Tetric Ceram) specimens were prepared, aged (min 7 d), and step-stress Hertzian contact fatigue tested (n=21) and inspected with failure = visually evident radial crack. Cements employed were: low Emod (1.3 GPa), Superbond C&B (C&B); intermediate (6 GPa), Variolink (VL); high (18 GPa), Panavia F (Pan). Ceramic intaglio surface was as received (1200 grit)(AR), sandblasted with 50 µm alumina (SB), SB + HF etched for 20 (SBE20), and only etched (ARE20, ARE120). Silane applied in all instances. Reliability was calculated (Relisoft Alta Pro) for a mission of 100K cycles at 250 N or 350 N load)
Results: The reliability results are summarized in the table
Conclusions: Etching appears to remove sandblasting damage.
Increasing the etch time/depth increases the bonded ceramic reliability.
Increasing the cement Emod from low to high significantly increased reliability.
The interplay between sandblasting damage and the effects of etching depth and cement elastic modulus creating an FGL and it effects on ceramic reliability is continuing to be explored.
Methods: Flat trilayer (ceramic-e.max CAD/cement/composite-Tetric Ceram) specimens were prepared, aged (min 7 d), and step-stress Hertzian contact fatigue tested (n=21) and inspected with failure = visually evident radial crack. Cements employed were: low Emod (1.3 GPa), Superbond C&B (C&B); intermediate (6 GPa), Variolink (VL); high (18 GPa), Panavia F (Pan). Ceramic intaglio surface was as received (1200 grit)(AR), sandblasted with 50 µm alumina (SB), SB + HF etched for 20 (SBE20), and only etched (ARE20, ARE120). Silane applied in all instances. Reliability was calculated (Relisoft Alta Pro) for a mission of 100K cycles at 250 N or 350 N load)
Results: The reliability results are summarized in the table
Conclusions: Etching appears to remove sandblasting damage.
Increasing the etch time/depth increases the bonded ceramic reliability.
Increasing the cement Emod from low to high significantly increased reliability.
The interplay between sandblasting damage and the effects of etching depth and cement elastic modulus creating an FGL and it effects on ceramic reliability is continuing to be explored.