Two-body wear of different ceramic materials opposed to zirconia ceramic
Statement of problem
Little is known about the wear behavior of ceramics opposed to unveneered zirconia and whether wear varies according to microstructure, surface toughness, and flexural strength of the ceramics.
Purpose
The purpose of this study was to evaluate the 2-body wear resistance of 5 ceramics opposing unveneered zirconia ceramic.
Material and methods
Yttrium-stabilized zirconia, lithium disilicate glass ceramic, leucite-reinforced glass ceramic, fluorapatite glass ceramic, and nanofluorapatite glass ceramic specimens (n=8) were tested against standardized zirconia balls. Wear tests were performed in a dual-axis mastication simulator. Wear resistance was calculated by measuring the vertical and volumetric substance loss using a laser scanner. Specimen surfaces were evaluated at x50 and x500 magnification using SEM. Data were statistically analyzed using 1-way ANOVA and Fisher's exact test (α=.05).
Results
Zirconia specimens demonstrated significantly lower vertical and volumetric loss than other ceramics (P<.05). The wear of fluorapatite and nanofluorapatite glass ceramics was significantly greater than that of leucite-reinforced and lithium disilicate glass ceramics (P<.05). SEM images showed no cracks or flaws in the zirconia and leucite-reinforced glass-ceramic specimens, indicating a mixture of attritional and adhesive wear. Other ceramic specimens exhibited cracks and chipped particle spaces which were consistent with fatigue wear. Zirconia demonstrated the lowest vertical and volumetric wear values. Leucite-reinforced and lithium disilicate glass ceramics demonstrated nonsignificant differences in volumetric wear, but these values were significantly lower than those observed for nanofluorapatite and fluorapatite glass ceramics (P<.05).
Conclusions
Wear varied according to the structure of the ceramic tested. Wear was of the fatigue type, and was significantly lowest in the zirconia specimens tested.
aProfessor, Department of Conservative Dentistry, Jordan University of Science and Technology, Irbid, Jordan
bVisiting Assistant Professor, Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Kiel, Germany
cProfessor and Chairman, Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Kiel, Germany
Corresponding author: Dr Zakereyya Albashaireh, Department of Conservative Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, PO Box 3030, Irbid 22110, JORDAN, Fax: +962-2-7279235
ABSTRACT