Introduction: Composites have been used in dentistry for several years. They consist of a core, a hardening phase and additives that improve the adhesion between them. Composites with a polymer core are used in dental prosthetics. They can also be applied to alloys requiring mechanical or chemical retention. Purpose: Determine the shear strength between the composites and the alloys, the difference in bond strength between light and heat cured composites and define based on the shear test results which bond between the alloy and composite is the best option. Methods of work: A descriptive method is used for the thesis, while the practical part is based on an analysis of the shear test results. Results: The samples were made of two alloys with dimensions of Φ 4.3 mm × 1 cm, Ag-Pd and Co-Cr, and three different composites with dimensions of Φ 4.3 mm × 4 mm, of which one is heat cured and two are light cured. We obtained the results based on shear tests. With the help of a computer programme connected to the testing device generated graphs of the shear force plotted as a function of the elongation. We calculated the shear strength based on the highest measured force and the boundary-surface area between the composite and the alloy. Discussion and conclusion: The aim of the research was to determine the shear strength of the bonds for three different composites and two different alloys. The findings showed that there are no major differences between the shear strengths of the different composites and alloys. Neither is there any significant deviation from the shear strengths found in the literature. The shear strengths are low, so we advise against the use of these materials for the production of coatings.
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