Evaluation of air-particle abrasion of Y-TZP with different particles using microstructural analysis.

BACKGROUND This study evaluated the effect of air-particle abrasion with different particle sizes on the surface roughness and phase transformation of yttria-stabilized tetragonal zirconia ceramics (Y-TZP). METHODS Eighty-four Y-TZP discs of 15 mm diameter and 1.0 mm thickness were fabricated. The samples were divided into four groups (n = 21): (1) air-particle abrasion with 30 μm CoJet sand blast coating agent (CoJet, 3M ESPE); (2) 50 μm Al2O3 particles; (3) 110 μm Al2O3 particles; and (4) 250 μm Al2O3 particles. Each group was further divided into three subgroups each (n = 7) and treated for 5 seconds, 15 seconds and 30 seconds. Mean surface roughness was determined using a profilometer. The surfaces were analysed with a scanning electron microscope. XRD analysis was employed and the relative amount of the monoclinic phase was calculated. The results were statistically analysed by two-way analysis of variance (ANOVA, p < 0.05). RESULTS Air-particle abrasion with 250 μm Al2O3 particles for 30 seconds had the highest surface roughness (p < 0.001) and a significantly higher amount of monoclinic phase compared to air-particle abrasion with 30 μm, 50 μm and 110 μm particles (p < 0.001). CONCLUSIONS Duration and particle size of air-particle abrasion affects the roughness and phase transformation of Y-TZP. Longer treatment times with larger particles may result in degradation of material.