Mechanical properties of alumina-zirconia composites for ceramic abutments

Abstract

The need for new materials to substitute injured or damaged parts of the human body has led scientists of different areas to investigate bioceramics since the 70's, when other materials in use started to show rejection problems. Ceramics show some advantages like being the material that best mimics the bone tissue, although present low toughness when compared with the metallic materials. As patients have become more and more demanding regarding esthetic and biocompatibility aspects of their dental restorations, ceramic material has become a main object of scientific interest especially from the material point of view. The alumina-zirconia composites are one of the relatively good and promising candidate for biomaterials application, due to biocompatibility and their mechanical properties that combines high flexural strength with a high toughness. The aim of the present work is to analyze the mechanical properties of these composites, where Y-TZP zirconia content was varied from 5 to 80 wt.% These systems can achieve a flexural strength 93 % and fracture toughness 29 % superior when compared to the pure alumina ceramics. These results showed that ceramic abutments components can be prepared for prosthetic rehabilitations with dental implants

Relationship between residual stresses and mechanical behavior in ceramic composites

“…Such similarity was consistent with the behaviors discussed before as to the microstructure equality and density of the materials obtained by the two methods. It is observed that the values of elastic modulus were decreased as Y-TZP content increases in A/Y-TZP composites, being in accordance with reports in [172,178,179]. The obtained E values were close to prediction by rule of mixtures starting from the values corresponding to a slip casting alumina material with 99% of theoretical density (E = 400 GPa, v = 0.22) and those corresponding to Y-TZP (E = 210 GPa, v = 0.31), demonstrated the high density and low defects number in materials.…”

“…Narrow grain size distributions were observed for both phases in each composite. It was clear that the fine and bimodal distribution of particle sizes allowed the most efficient fulfilling of the matrix for uniaxially pressing, promoting better densification of the powders [172].…”

Effect of 3 mol% Yttria Stabilized Zirconia Addition on Structural and Mechanical Properties of Alumina-Zirconia Composites

“…The applied load was 19.614 N for 6 second over polished surface. The values of microhardness were calculated from the following equation [8]:…”

“…Composites with higher density and lower porosity offer better mechanical properties [8]. The presence of porosity can reduce fracture toughness by the reduction of the resistant area by the effect of stress concentration in the pores.…”

Experimental Unit for Studying the Influence of Additives on the Properties of Concrete

“…Повышенная водопотребность мелких песков отрицательно сказывается на показателях прочности и плотности что приводит к формированию проницаемой структуры. Полученные данные хорошо согласуются с подобными исследованиями проводимыми в России и за рубежом [7][8][9][10].…”