Roughness evaluation after surface treatments of aluminous ceramic

Bond strength between high-alumina ceramic and luting cements may be improved if alumina surface roughness is increased. Objective: The aim of this study was to evaluate the influence of different surface treatments on surface roughness of In-Ceram Alumina (aluminous ceramic, 82% vol. alumina, infiltrated by glass: Vita). Methods: Ceramics blocks were polished (4000 grit) and following treatments were performed: 1) Sandblasting (SB)- airborne particle abrasion Al₂O₃ (110 μm particle size), (2.8 bars; 20s). 2) Rocatec System (RC)- after SB treatment, sandblasting with silica powder (50 μm particle size), (2.8 bars, 20 s). 3) Nd:YAG Laser (ND)- after SB treatment, application of graphite powder (stain) on the ceramic surface and Nd:YAG laser irradiation (distance: 1 mm; 100 mJ, 20 Hz, 2 W, and 141.54 J/cm2). 4) Nd:YAG Laser plus Rocatec System- after SB and ND treatments, RC was applied. Digital images (20x20 microns) from the surfaces were obtained by means of an AFM microscope in taping mode (Nanoscope IIIa- Digital Instruments). Roughness was measured in 10x10 microns boxes. Roughness (Ra) data (nm) were analyzed by One-way Anova (p<0.05). Results: Mean roughness (Ra-nm) and standard deviations are presented in the table. No differences were found between groups (P=0.5441). Conclusions: Tested treatments were not able to increase surface roughness of the tested alumina surfaces.

Acknowledgements:CICYT/FEDER-MAT2004-06872-C03-02,FAPESP#2005/01918-5.