The effect of gamma irradiation on the synthesis, microbiological sterility, and improvement of properties of PMMA-Al2O3 composite used in dental prosthesis manufacturing

Polymethyl methacrylate (PMMA) is a polymer material widely used in dental applications due to its excellent biocompatibility, stable physicochemical properties, easy manipulation, and low cost. The combination of biocompatible polymers and ceramics has great potential for the development of materials in the dental industry with improved mechanical properties. The addition of Al2O3 nanoparticles to PMMA can significantly improve its compressive and flexural strengths and wear resistance. Since this material is used in dental applications, it requires a high degree of product sterility. This can easily be achieved with gamma radiation treatment. Gamma radiation not only ensures the sterility of the product but can also affects changes in numerous material properties. The aim of this paper is to determine the influence of different doses of gamma radiation on the microbiological purity and changes in the mechanical and thermal properties of the PMMA/Al2O3 composite as well as the microstructural and color changes. It was found that the dose of radiation of 25 kGy is sufficient for complete sterilization of the product. This radiation dose improves the mechanical properties of the material and thermal stability. On the other hand, the dose of 25 kGy does not affect the morphology of the exposed sample and has small effect on the color change