الفهرس 
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Abstract
SUMMARY
T
he purpose of this study was to assess the effect of different finishing & polishing protocols on surface roughness and biaxial flexural strength of monolithic cubic zirconia after dry and wet grinding.
Smoothness of a restoration is a crucial factor for its durability and survival in the oral cavity. It has its impact on the biological, mechanical and esthetic aspects of the restoration. Glazing is the most common laboratory procedure for attaining an ideally finished smooth restoration. However, this is not always the case, there are situations where adjustments and modifications are required. Therefore, it is highly recommended that the adjusted surface is finished and polished appropriately.
The translucency of cubic zirconia is improved on expense of its strength so the grinding and finishing may affect its mechanical properties. Thus, it was important to evaluate the most convenient finishing protocol with this material.
Forty samples were prepared from Super Translucent Multi-Layer (STML) zirconia. They were divided into 3 groups according to the surface grinding: group (C): control (no grinding-as glazed) (n=8), group (D)grinding under dry condition (n=16) and group (w) grinding under wet condition (n=16). Groups (D)and(W) were subdivided into 2 subgroups according to surface finishing whether reglazing or polishing.
The surface roughness average (Ra) was measured using contact profilometer. Then, the biaxial flexural strength test was done using a universal testing machine.
The reglazing showed a statistically significant higher mean Ra than polishing whether after wet or dry grinding. The dry ground groups showed a statistically significant higher mean Ra than wet ground groups.
The reglazing showed a statistically significant lower mean biaxial flexural strength than polishing after dry grinding. While there was no statistically significant difference between reglazing and polishing after wet grinding.