Introduction: Although the current trend in fixed prosthetics is the use of full-ceramic dental restorations, research has shown that metal-ceramic dental restorations are still most commonly used due to good clinical efficiancy, lower cost, easy cementing technique and aesthetic appearance. In the manufacture of metal-porcelain restorations, as in any other prosthetic care, there may occure specific errors for this technique, which must be prevented throughout the manufacturing process. The most common errors are the appearance of internal stresses at the alloy-porcelain boundary, inadequate porcelain thickness, porcelain crumbling, inadequate metal frame thickness, porosity in metal framework, development of holes and porosity in porcelain layer and discoloration. When grinding the framework with multi-directional strokes and excessive pressure on the metal, plastic deformation, bumps and bulges occure on the rough surface of the metal framework, which can entrap impurities, ground particles of the metal alloy and air. This can result in porosity and dirt entrapment in the metal-porcelain bond and in the porcelain layer during the sintering phase. This can be avoided by one-way grinding and the following sandblasting. Purpose: The purpose of this diploma work is to investigate and determine how different techniques of mechanical treatment of the metal framework surface affect the occurrence of defects in the porcelain layer and the metal-porcelain bond. Methods: Based on a review of existing research, we chose the topic and title of the diploma work and summarized the theoretical background, important for understanding later research work. We made samples with different processing methods and techniques, then we prepared samples for metallographic. Results: We presented the manufacturing procedure of six different samples, praparation and results of metallographic analysis. Discussion and conclusion:: We confirm that the best mannufacturing method is grinding with abrasive stones in one direction and that sandblasting is necessary to remove dirt and prepare the surface of the metal framework before oxitation proces and aplication of porcelain. Samples with metal framework grinded in several directions have a rougher surface, a thicker oxide layer, and more porosity and impurities in the porcelain layer. Samples with framework that have not been sandblasted have a smooth surface of a metal framework that forms an uneven oxide layer in which impurities are trapped, which can later enter the porcelain layer.
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