Evaluation of alumina effects on the mechanical property and translucency of nano-zirconia all-ceramics / 中华口腔医学杂志
Chinese Journal of Stomatology
;
(12): 376-380, 2010.
Article
in Chinese
| WPRIM
| ID: wpr-243127
ABSTRACT
<p><b>OBJECTIVE</b>To study the effects of alumina content on sintered density, mechanical property and translucency of zirconia nanocomposite all-ceramics.</p><p><b>METHODS</b>Specimens of zirconia nanocomposite all-ceramics were divided into five groups based on their alumina content which are 0% (control group), 2.5%, 5.0%, 7.5% and 10.0% respectively. The sintered densities were measured using Archimedes' method. Specimens' bending strengths were measured with three-point bending test (ISO 6872). The visible light transmittances were measured with spectrophotometric arrangements and the fractured surfaces were observed using scanning electron microscope (SEM).</p><p><b>RESULTS</b>The control group of pure zirconia could be sintered to the theoretical density under pressure-less sintering condition. The bending strength was (1100.27 ± 54.82) MPa, the fracture toughness was (4.96 ± 0.35) MPa×m(1/2) and the transmittance could reach 17.03%. The sintered density and transmittance decreased as alumina content increased from 2.5% to 10%. However, the fracture toughness only increased slightly. In all four alumina groups, the additions of alumina had no significant effect on samples' bending strengths (P > 0.05). When the content of alumina was 10%, fracture toughness of specimens reached (6.13 ± 0.44) MPa×m(1/2) while samples' transmittance declined to 6.21%. SEM results showed that alumina particles had no significant effect on the grain size and distribution of tetragonal zirconia polycrystals.</p><p><b>CONCLUSIONS</b>Additions of alumina to yttria-tetragonal zirconia polycrystals could influence its mechanical property and translucency. Additions of the other phase to zirconia ceramics should meet the clinical demands of strength and esthetics.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Surface Properties
/
Yttrium
/
Zirconium
/
Materials Testing
/
Microscopy, Electron, Scanning
/
Ceramics
/
Chemistry
/
Pliability
/
Dental Porcelain
/
Dental Stress Analysis
Language:
Chinese
Journal:
Chinese Journal of Stomatology
Year:
2010
Type:
Article
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