Mechanical and Biological Characterization of PMMA/Al2O3 Composites for Dental Implant Abutments

Abstract

The mechanical and biological behaviors of PMMA/Al2O3 composites incorporating 30 wt.%, 40 wt.%, and 50 wt.% of Al2O3 were thoroughly characterized as regards to their possible application in implant-supported prostheses. The Al2O3 particles accounted for an increase in the flexural modulus of PMMA. The highest value was recorded for the composite containing 40 wt.% Al2O3 (4.50 GPa), which was about 18% higher than that of its unfilled counterpart (3.86 GPa). The Al2O3 particles caused a decrease in the flexural strength of the composites, due to the presence of filler aggregates and voids, though it was still satisfactory for the intended application. The roughness (Ra) and water contact angle had the same trend, ranging from 1.94 µm and 77.2° for unfilled PMMA to 2.45 µm and 105.8° for the composite containing the highest alumina loading, respectively, hence influencing both the protein adsorption and cell adhesion. No cytotoxic effects were found, confirming that all the specimens are biocompatible and capable of sustaining cell growth and proliferation, without remarkable differences at 24 and 48 h. Finally, Al2O3 was able to cause strong cell responses (cell orientation), thus guiding the tissue formation in contact with the composite itself and not enhancing its osteoconductive properties, supporting the PMMA composite’s usage in the envisaged application.

Influence of Dry-Mixing and Solvent Casting Blending Techniques on the Mechanical and Biological Behavior of Novel Biocompatible Poly(ε-caprolactone)/Alumina-Toughened Zirconia Scaffolds Obtained by 3D Printing

“…To assess the biological compatibility of the composites, a widely used mesenchymal stem cell model was adopted [9,23]. ASC52hTert (ATCC) adipose stem cells were cultured in Alpha-MEM (Life Technologies, Milano, Italy) supplemented with 10% FBS, 100 U/mL penicillin, and 100 µg/mL streptomycin.…”

“…New biomaterials combining the mechanical features of tailored synthetic polymers with the biocompatible element of inorganic fillers have been proposed, thus minimizing the pitfalls of each component while exploiting their own favorable properties to generate a superior hybrid material. However, for biomedical applications composite technology is mainly used for improving a variety of mechanical, thermal, and biological properties of inert polymers [7][8][9][10]. Alumina-Toughened Zirconia (ATZ)-based massive ceramics display the most suitable biological features [11], but are hindered by their mechanical properties, limiting their use in load-bearing applications.…”