According to the World Health Organization (WHO), dental caries is a prevalent disease, which affects the majority of school children and almost all adults in most countries. Apart from prevention, the dental profession is trying to fight this global problem with the development of so-called bioactive or biomimetic materials that could, besides reconstructing the defective tissue, stimulate certain biological responses and provide resistant and long-term restorations. Therefore, the aim of this project is an interdisciplinary investigation and enhancement of properties of bioactive materials properties used in different fields of dental medicine for reconstruction, regeneration and reparation. The first part of the research is focused on bioactive glass ionomer cements (GIC). These materials chemically bond to the tooth surface and have a remineralizing and cariostatic effect. However, their disadvantages are poor physical and mechanical properties. The first aim of this project is to investigate the possibility of enhancing glass ionomers by adding fibers and nanoparticles in different ratios and to assess the strength, hardness, modulus of elasticity, remineralization potential and adhesion to the tooth surface. Subsequently, the project will be focused on the investigation of bioceramics as a new bioactive material for root canal filling. Bioceramics should stimulate the vital periodontal tissue and provide a good seal. Therefore, the second aim of the project is to assess the relation of bioceramic materials and tooth structure in the endodontic system by investigating the sealing ability before and after dynamic loading and the possibilities of the removal of bioceramics using micro-CT. With dynamic loading, we are attempting to simulate the conditions in the oral cavity, which is necessary to correctly assess the behavior of the materials under clinical conditions. Biomechanical studies in dental medicine are time- consuming and expensive and the data obtained with high-resolution micro-CT will serve for development of 3D mathematical models with finite element analysis so that in the future the behavior of teeth in interaction with different materials and factors in oral cavity could be assessed. The originality of the proposed research lies in the detailed assessment of bioactive materials, which should result in the better understanding of their structure and properties. It should also enable the development of better protocols for clinical application of the materials. Furthermore, the results of the analysis of different reinforcements of biomaterials will direct research towards enabling the materials to evolve even further.