The evaluation of surface treatment effects of Zirconia and Alümina based full ceramics on flexural strengths

All ceramic systems have become increasingly popular due to their esthetic and biocompatible properties. Alumina and zirconia are frequently used for dental prosthetic restorations because of their high strengths and good esthetic appearance. However, mechanical properties of these materials can be directly influenced by different surface treatment methods. The purpose of this study was to evaluate the effect of surface grinding and sandblasting on flexural strength of yttria stabilized tetragonal zirconia and alümina core materialsSpecimens of Y-TZP and Alümina core materials were fabricated with a dimensions of 2x4x25 mm. Alümina specimens was processed by glass infiltrating a porous alumina preform made by slip casting in a mold. Y-TZP specimens was produced from a computer assisted design/computer-aided manufacture (CAD/CAM) system. Forty bars from each materials were randomly divided into four groups of ten. For each group, a different surface treatment was applied; 50 ?m grinding, 150 ?m grinding, sandblasting and a control group. Uniaxial flexural strength ( three point bending) was determined for all specimens. The data were analyzed by using the one-way ANOVA test. Multiple comparison was performed with the Duncan test. p<0,05 were cosidered as statistically significant.All surface treatments significantly decreased the flexural strength values of Alümina materials. The mean uniaxial flexural strength values of control and surface treatment groups in Alümina materials were significantly different (p<0.05). In Y-TZP materials, grinding of 50 ?m diamond bur increased the flexural strength but grinding of 150 ?m diamond bur and sandblasting decreased the flexural strength. The mean uniaxial flexural strength values of all groups in Y-TZP materials were not significantly different (p>0.05).