Enhanced mechanical properties of ZrO-AlO dental ceramic composites by altering AlO form.

OBJECTIVES

This study evaluates the difference in physical and mechanical properties of ZrO ceramics, commonly used in dental applications, altered by three different forms of AlO content; microparticles (m), nanoparticles (n), and microfiber (f).

METHODS

Three different types of ZrO-AlO composites were formed using microparticle (m), nanoparticle (n), or microfibre (f) forms of AlO. The physical and mechanical properties such as sintering shrinkage, relative density, Vickers hardness, fracture toughness, and biaxial strength were evaluated. A Weibull analysis was performed to assess the strength reliability of the specimens. All data were calculated using the t-test and ANOVA.

RESULTS

The sintering shrinkage and relative density of all ceramic composite groups were decreased with the addition of AlO. The mechanical properties of ZrO-AlO (f) composite were higher than that of ZrO-AlO (m) composite and ZrO-AlO (n) composite. The maximum hardness, fracture toughness, and biaxial flexural strength were observed for 10 vol% of AlO fibre. When the content of AlO fibre in the matrix was increased above 20 vol%, agglomeration occurred and resulted in a decrease of hardness and toughness. The Weibull modulus value of the ZrO-AlO (f) composite was the lowest compared to that of other groups. However, characteristic strength (σ) of ZrO-AlO (f) the highest value.

SIGNIFICANCE

The current study demonstrated that the addition of right amount of AlO microfibre into the ZrO matrix enhanced the mechanical properties of ZrO-AlO (f) composite, which would be favourable for dental applications.