Ceramics and Glass-Ceramics Dental Materials: Chemical Solubility, Cytotoxicity and Mechanical Properties

Abstract:

In this work three dental ceramics were characterized according to ISO 6872: yttria-stabilized zirconia (ZrO₂-Y₂O₃), lithium disilicate (Li₂Si₂O₅) and the spinel-zirconia composite (MgAl₂O₄-ZrO₂). The zirconia ceramic and the zirconia-spinel composite were sintered at 1600°C-2h, while the lithium disilicate was thermally treated at 820°C-20min. These materials were characterized by relative density, X-ray diffraction, scanning electron microscopy, hardness, fracture toughness, chemical solubility and cytotoxicity. The XRD results showed for the stabilized zirconia only the tetragonal phase of ZrO₂, and to the composite only the phase MgAl₂O₄, Li₂Si₂O₅ was the only phase to lithium disilicate. Relative density results showed that the zirconia and the lithium disilicate showed high densification (> 99.5%) and the composite had a relative density of 75% (10% composite doped with ZrO₂) and 90% (50% doped with ZrO₂). Hardness and toughness showed 450HV and 3.2MPa.m^1/2 to ZrO₂-MgAl₂O₄ composites, 525HV and 1.8MPam^1/2 to lithium disilicate and 1280HV and 8.0MPa.m^1/2 to zirconia. The materials evaluated showed chemical solubility <30μg/cm² and the results of cytotoxicity tests indicated cell viability of the samples near 100% for all the materials, showing good chemical stability and potential for dental applications.

• Periodical: Materials Science Forum (Volume 912)
• Pages: 170-174
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.912.170
• Online since: January 2018
• Authors: Roberto de Oliveira Magnago, Carlos Eduardo de Lima Abreu, Ronaldo Reis Silva, Manuel Fellipe Rodrigues Pais Alves, Caio Marcelo Felbinger Azevedo Cossu, Claudinei dos Santos
• Keywords: Characterization, Dental Material, Lithium Disilicate, Spinel, Zirconia

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