Introduction: Dental ceramics have long justified their use in dentistry. In order to be used
in the field of dental technology, it must not only be safe and non-invasive for the host’s
body, but also provide good mechanical properties and a high aesthetic appearance. Such
ceramics are called bioceramics and include glass-ceramics, which is still the most
commonly used material in dentistry today. As is typical for all ceramic materials,
bioceramics are brittle, with cracks appearing on the surface of the material already in the
elastic range of the load. In the field of dentistry, this problem is most often solved by the
addition of metal materials or by the construction of metal-ceramic crowns or bridges,
which unfortunately reduces the desired aesthetics. In modern fixed prosthodontics full
ceramic frameworks made of aluminium (Al2O3) and zirconium oxide (ZrO2) have
emerged as a response to this challenge. Compared to metal-ceramic structures, these
materials boast high strength and hardness, temperature stability, high resistance to
aggressive environments, corrosion and abrasion resistance, and better translucency than
glass-infiltrated ceramics. This allows us to provide the patient with a material that has
good mechanical properties and at the same time offers a high aesthetic appearance. For
optimum properties to be achieved depends on the purity of the powder, the particle size
distribution, and the compression and sintering conditions. Purpose: The aim of this study
is to analyse the structure and properties of ZrO2 and Al2O3 ceramics and to determine
which of the two already prescribed technologies (ZrO2 and Al2O3) provides a more
consistent product quality with a smaller deviation of mechanical properties from the
prescribed values. This has revealed which material is more reliable and therefore more
suitable for dental crowns. Additionally, the aim of my thesis was to produce two zirconia
ceramic substitutes. Methods: The thesis consists of a theoretical and an experimental part.
In the theoretical part, an analysis of the structure and properties of the selected materials
was performed using the literature available on the Google Scholar website and the
Ljubljana Medical Library. In the experimental part, Al2O3 and ZrO2 test specimens were
made based on the prescribed technologies and used for mechanical tests. All subjects were
tested under the same conditions. Results: The test specimens were prepared in the
Dentom dental laboratory in Ljubljana and the Franc Rojko dental laboratory in Ptuj. The
tests were made at the Institute of Materials Technology at the Faculty of Mechanical
Engineering University of Maribor. Discussion and conclusion: Based on the bending
tests, which were used to determine the fracture modulus of zirconia and alumina ceramics,
it can be summarised that zirconia ceramics have a higher fracture modulus and higher
fracture toughness and as a consequence these ceramics are more suitable for the
fabrication of larger dental prosthetics constructions. The results also show that the
prescribed zirconia ceramics manufacturing technology ensures lower variation and higher
constancy of properties.
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