The effect of different cooling rates and coping thicknesses on the failure load of zirconia-ceramic crowns after fatigue loading
The Journal of Advanced Prosthodontics
; : 152-158, 2017.
Article
em En
| WPRIM
| ID: wpr-71188
Biblioteca responsável:
WPRO
ABSTRACT
PURPOSE:
The purpose of this study was to evaluate the influence of different coping thicknesses and veneer ceramic cooling rates on the failure load of zirconia-ceramic crowns. MATERIALS ANDMETHODS:
Zirconia copings of two different thicknesses (0.5 mm or 1.5 mm; n=20 each) were fabricated from scanning 40 identical abutment models using a dental computer-aided design and computer-aided manufacturing system. Zirconia-ceramic crowns were completed by veneering feldspathic ceramics under different cooling rates (conventional or slow, n=20 each), resulting in 4 different groups (CONV05, SLOW05, CONV15, SLOW15; n=10 per group). Each crown was cemented on the abutment. 300,000 cycles of a 50-N load and thermocycling were applied on the crown, and then, a monotonic load was applied on each crown until failure. The mean failure loads were evaluated with two-way analysis of variance (P=.05).RESULTS:
No cohesive or adhesive failure was observed after fatigue loading with thermocycling. Among the 4 groups, SLOW15 group (slow cooling and 1.5 mm chipping thickness) resulted in a significantly greater mean failure load than the other groups (P<.001). Coping fractures were only observed in SLOW15 group.CONCLUSION:
The failure load of zirconia-ceramic crowns was significantly influenced by cooling rate as well as coping thickness. Under conventional cooling conditions, the mean failure load was not influenced by the coping thickness; however, under slow cooling conditions, the mean failure load was significantly influenced by the coping thickness.Palavras-chave
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Base de dados:
WPRIM
Assunto principal:
Cerâmica
/
Adesivos
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Desenho Assistido por Computador
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Coroas
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Fadiga
Idioma:
En
Revista:
The Journal of Advanced Prosthodontics
Ano de publicação:
2017
Tipo de documento:
Article