Effects of multiple firings on the microstructure of zirconia and veneering ceramics

• Published in: Dental Materials Journal Vol. 35; no. 5; pp. 776 - 781
• Main Authors: ALKURT, Murat, DUYMUS, Zeynep YEŞIL, GUNDOGDU, Mustafa
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society for Dental Materials and Devices 2016; Japanese Society for Dental Materials and Devices
• Subjects: Analysis of variance; Burning time; Ceramics; Dental materials; Dental Porcelain; Dental Veneers; Dentistry; Firing; Materials Testing; Microstructure; Surface Properties; Veneering; Vickers hardness test; XRD; Yttria stabilized zirconia; Zirconium; Zirconium dioxide
• ISSN: 0287-4547; 1881-1361
• DOI: 10.4012/dmj.2015-429

The aim of study was to evaluate the effects of multiple firings on the microstructures of zirconia and two ceramics. Vita VM9 (VMZ) and Cerabien ZR (C-Z) ceramics on a zirconia framework and zirconia without veneering ceramic (WO-Z) were evaluated. Firing methods included firing two, five, and ten times (n=10). The effects of multiple firings on the surface hardness of the materials were evaluated using a Vickers hardness (HV) tester. Data were analyzed by two-way ANOVA and Tukey’s test (α=0.05). After firing five and ten times, the hardness of VM-Z and C-Z increased significantly (p<0.001). The HVs of the Cerabien ZR and Vita VM9 veneering ceramics were similar (p>0.05). In the XRD analysis, zirconia had similar tetragonal (t)–monoclinic (m) phase transformations of Y-TZP after the different firing times. Clinically, multiple firings did not affect the microstructure of zirconia, but the structures of the two ceramics were affected.