Influence of different surface treatments on surface zirconia frameworks

Objectives: To evaluate the effect of different chemo-mechanical surface treatments of zirconia ceramic in the attempt to improve its bonding potential. Methods: Sintered zirconium oxide ceramic discs (Lava (TM) circle divide 10 mm x 1 mm height) were treated with (n = 4): (1) airborne particle abrasion with 125 mu m Al2O3 particles; (2) 9.5% HF acid etching; (3) selective infiltration etching (SIE); (4) experimental hot etching solution applied for 10, 30 and 60 min; (5) no treatment. Ceramic discs surfaces were analyzed by atomic force microscopy (AFM) recording average surface roughness measurements of the substrate. Data were statistically analyzed by Kruskall-Wallis analysis of variance and Mann-Whitney tests (alpha = 0.05). The same discs were used for bi-dimensional zirconia ceramic surface characterization with scanning electron microscope (SEM). Results: Ceramic surface treatments significantly influenced surface topography and roughness (p < 0.001). Bi-dimensional changes in ceramic surface morphology were assessed on a nanometric scale. The experimental hot etching solution improved surface roughness, independently from the application time. Conclusion: Zirconia conditioning with the experimental hot etching solution may enhance ceramic roughness and improve the surface area available for adhesion allowing the formation of micromechanical retention. The influence of this surface treatment with regard to bond strength of zirconia needs to be addressed. (C) 2009 Elsevier Ltd. All rights reserved.