In vitro performance of full-contour zirconia single crowns

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• 作者：Florian Beuer^a ; ^{florian.beuer@med.uni-muenchen.de} ; Michael Stimmelmayr^b ; Jan-Frederik Gueth^a ; Daniel Edelhoff^a ; Michael Naumann^c
• 关键词：Zirconia ; CAD/CAM ; Veneering porcelain ; Full-contour ; Single crown
• 刊名：Dental Materials
• 出版年：2012
• 出版时间：April, 2012
• 年：2012
• 卷：28
• 期：4
• 页码：449-456
• 全文大小：1149 K

文摘

Objectives

Zirconia based restorations exhibited high failure rates due to veneering-porcelain fractures. Milling to full-contour might be an alternative approach for zirconia restorations. The aim of this study was to evaluate full-contour zirconia crowns in terms of light-transmission, contact wear (restoration and antagonist) and load-bearing capacity. Powder build-up veneered zirconia substructures and CAD/CAM-veneered zirconia substructures served as controls.

Methods

Four different kinds of crowns were fabricated on 12 metal dies: zirconia substructure with powder build-up porcelain (veneering technique), zirconia substructure with CAD/CAM generated veneering (sintering technique), full-contour zirconia glazed (glazed full-contour) and full-contour zirconia polished (polished full-contour). All crowns had the same dimensions. After light-transmission was measured the crowns were cemented on the corresponding metal dies. The specimens were loaded according to a special wear method in the chewing simulator (120,000 mechanical cycles, 5 kg load, 0.7 mm sliding movement, 320 thermocycles). Wear of the restoration and the antagonist were measured. All specimens were loaded until failure. One-way ANOVA and a LSD post-hoc test were used to compare data at a level of 5 % .

Results

Polished full-contour showed significantly higher light transmission than the other groups (p = 0.003; ANOVA). Polished full-contour exhibited significantly less contact wear at the restoration (p = 0.01; ANOVA) and higher contact wear at the antagonist (p = 0.016; ANOVA) compared to the other groups. Glazed full-contour zirconia showed similar contact wear at the antagonist compared to veneering technique (p = 0.513, post-hoc LSD). Crowns with conventional veneering showed significantly lower load-bearing capacity (p < 0.001; ANOVA).

Significance

Milling zirconia to full-contour with glazed surface might be an alternative to traditionally veneered restorations.