title: Effects of multiple firings on the microstructure of zirconia and veneering ceramics.
abstract: 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.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Recep Tayyip Erdogan University.
authors.forename: Murat
authors.initials: M
authors.lastname: Alkurt
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Yeşil Duymus
authors.forename: Mustafa
authors.initials: M
authors.lastname: Gundogdu
mesh_terms: D002516:Ceramics; D003776:Dental Porcelain; D003801:Dental Veneers; D008422:Materials Testing; D013499:Surface Properties; D015040:Zirconium
chemical_list: D003776:Dental Porcelain; D015040:Zirconium