effects of different lasers and particle abrasion on surface characteristics of zirconia ceramics.

the aim of this study was to assess the surface of yttrium-stabilized tetragonal zirconia (y-tzp) after surface treatment with lasers and airborne-particle abrasion.first, 77 samples of presintered zirconia blocks measuring 10 × 10 × 2 mm were made, sintered and polished. then, they were randomly divided into 11 groups (n=7) and received surface treatments namely, er:yag laser irradiation with output power of 1.5, 2 and 2.5 w, nd:yag laser with output power of 1.5, 2 and 2.5 w, co2 laser with output power of 3, 4 and 5 w, al2o3 airborne-particle abrasion (50μ) and no treatment (controls). following treatment, the parameters of surface roughness such as ra, rku and rsk were evaluated using a digital profilometer and surface examination was done by sem.according to anova and tukey's test, the mean surface roughness (ra) after nd:yag laser irradiation at 2 and 2.5 w was significantly higher than other groups. roughness increased with increasing output power of nd:yag and co2 lasers. treated surfaces by er:yag laser and air abrasion showed similar surface roughness. sem micrographs showed small microcracks in specimens irradiated with nd:yag and co2 lasers.nd:yag laser created a rough surface on the zirconia ceramic with many microcracks; therefore, its use is not recommended. air abrasion method can be used with er:yag laser irradiation for the treatment of zirconia ceramic.