Introduction: Metal-porcelain dental prothetics in Slovenija are still considered to be the most widely used, versatile and aesthetically satisfactory. Usually the basic construction is made of an alloy covered with a dental porcelain coat. However, the strength of the bond between the alloy and the porcelain coat depends on several variables. In measuring the strength of mechanical adhesion between the basic metal structure and the porcelain coating, we mainly tested the dependence of the mechanical properties on shear stress strength. The adhesion depends on the size of the particles we used to sandblast the alloy construction. It is important that we know all the variables and properties of the samples, and prepare the experiments under the same conditions. Purpose: The purpose of this experiment is to research and review the existing literature, and to discover which sandblasting with Al2O3 particles provides the best mechanical bond. Working methods: In the initial part we used the descriptive method with a review of the literature and the results of already conducted similar research on the topic of the diploma work. In conclusion, we present the results of the mechanical metal-ceramic adhesion by variously prepered samples sandblasted with different sizes of Al2O3 particles. Results: We prezented the procedures for the production of three different types of samples who were sandblasted with different particle sizes and the strength of their mechanical adhesion during the tests. Discussion and conclusion: We concluded by analyzing the results obtained by the shear strength test. We calculated the shear stresses and bursts of differently processed specimens. We found that the maximum shear strength forces of bursting and shear stresses were achieved with samples sandblasted with 250-?m Al2O3 particles. Therefore, it can be concluded that optimum mechanical adhesion between the alloy and dental porcelain, and hence of lower risk for cracking the porcelain coat, is ensured by sandblasting the metal frame with particles 250?m Al2O3 particles.
|
