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 Ø10mm x 1mm height) were treated with (n=4): (1) airborne particle abrasion with 125microm Al(2)O(3) particles; (2) 9.5% HF acid etching; (3) selective infiltration etching (SIE); (4) experimental hot etching solution applied for 10, 30 and 60min; (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

Morphological analysis of three zirconium oxide ceramics: Effect of surface treatments

Objective: To evaluate the effect of different chemo-mechanical surface treatments on the morphology of three recently marketed dental zirconia ceramics. Materials and methods: Ceramic discs ( 8 10 mm 7 1 mm height) were obtained from three sintered zirconia ceramics (Lava\u2122, Cercon\uae, and Aadva Zr) and treated with: (1) airborne particle abrasion with 125 \u3bcm Al2O3 particles (S); (2) selective infiltration etching (SIE); (3) experimental hot etching solution applied for 30 min (ST); (4) no treatment (C). Five discs per group were used for surface roughness analysis using an atomic force microscope (AFM). Data were statistically analyzed by Kruskall-Wallis analysis of variance and Mann-Whitney tests (\u3b1 &lt; 0.05). The same discs were evaluated under SEM for surface topography analysis. Three discs per group were cemented to a composite overlay (Paradigm MZ100) with a total-etch resin luting agent (Calibra) and cross-section interfacial analysis was performed under SEM. Results and Significance: Airborne particle abrasion improved the average surface roughness of Cercon\uae and Lava (p &lt; 0.05) while SIE induced significant changes on Lava and Adava Zr. Statistical differences in surface roughness were recorded after selective infiltration etching when compared to no treated group, independently from the zirconia type. SEM and AFM analyses revealed changes in surface topography for all the tested ceramics and intergrain spaces opening, especially after ST. The effectiveness of the tested chemo-mechanical surface treatments depends on the zirconia type. The hot experimental etching solution increased the surface roughness of all the tested ceramics creating retentive micro-spaces that may potentially improve zirconia/resin cement interfacial strengths. \ua9 2010 Academy of Dental Materials