Three-Point Bending Tests of Zirconia Core/Veneer Ceramics for Dental Restorations

Abstract

Introduction. The mechanical strength and the surface hardness of commercially available yttrium-doped zirconia were investigated. Furthermore, a comparative study of eight different ceramic veneers, to be used for the production of two-layered all-ceramic restorative systems, was carried out. Materials and Methods. Four types of zirconia specimens were analyzed, according to a standard ISO procedure (ISO 6872). Besides, two-layered zirconia-veneer specimens were prepared for three-point bending tests. Results. A strong effect of the surface roughness on the mechanical strength of zirconia specimens was observed. Finally, a comparative study of eight commercially available veneering ceramics shows different modes of failure between the selected veneers. Conclusion. The results indicate that close attention should be paid to the preparation of zirconia-based crowns and bridges by CAD/CAM process, because surface roughness has an important effect on the mechanical strength of the material. Finally, the results of the mechanical tests on two-layered specimens represent an important support to the choice of the veneering ceramic.

Biomechanical Behaviour of a Jawbone Loaded With a Prosthetic System Supported by Monophasic and Biphasic Implants

“…The case A shows a maximum stress slightly higher than that shown by the case B. In this outcome, it is important to evaluate the role of the geometry of the implants used, as well as the prosthesis chosen and integrated in the oral cavity (11,12). Moreover, the stress distribution on the mandibular ridge appears more uniform in case A, compared to the case B.…”

Influence of Heating Conditions for Formation of a Thin Apatite Film on Zirconia Using a Molecular Precursor Method

“…Animal experiments to elucidate the differences of CA coated Y-TZP at different heating conditions are needed in the near future. Moreover, Marrelli et al [23] reported that surface roughness of zirconia strongly affected the mechanical strengths. Change of the mechanical strengths of Y-TZP after CA coating should be further investigated.…”

Innovative approach for the in vitro research on biomedical scaffolds designed and customized with CAD-CAM technology

“…In conclusion, the reported biomechanical tests seem to confirm that the biomaterials subjected to CAM milling processes retain their physic properties and the only alterations are due to errors in the design stage. 3 Therefore, the comparability between two or more materials is an important prerequisite to clearly define the characteristics of the investigated materials. In recent years, regenerative medicine issues have stimulated research to investigate an elevated number of new biomatrices 4 aimed at improving tissue healing; in this light, the old concept of bioscaffolds has given way to new concepts, such as acellular scaffolds, 5 cell niche, and cell commitment.…”