Strength of 3Y-TZP and feldspathic porcelain subjected to different cooling methods

Autor(es)

Antonio Alves de Almeida-Júnior ^[1] ; Diogo Longhini ^[2] ; Beatriz Regalado Galvão ^[3] ; Claudinei dos Santos ^[4] ; Gelson Luis Adabo ^[5]

Afiliação do(s) autor(es)

^[1] Universidade Tiradentes. School of Dentistry. Department of Oral Rehabilitation - Brasil

^[2] Universidade Estadual Paulista. School of Dentistry. Department of Dental Materials and Prosthodontics - Brasil

^[3] Universidade Potiguar. School of Dentistry. Department of Oral Rehabilitation - Brasil

^[4] Universidade do Estado do Rio de Janeiro. Resende School of Technology. Department of Engineering Materials - Brasil

^[5] Universidade Estadual Paulista. School of Dentistry. Department of Dental Materials and Prosthodontics - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Braz. J. Oral Sci.; v. 13, n. 2, p. 124-128, 2014-06-00.

Resumo

AIM: To investigate the effect of the cooling rate on flexural strength of monolayer and bilayer porcelain/zirconia (Y-TZP) bars.METHODS: Forty-five specimens were made for each design group: (PM) monolithic specimens of veneer porcelain Vita VM9 (Vita, Germany); (ZM) monolithic specimens of zirconia (ZiHP; ProtMat, Brazil); (PB) bilayer specimens zirconia/porcelain with porcelain on lower surface; and (ZB) bilayer specimens porcelain/zirconia with zirconia on lower surface. Each group was cooled by three different methods after porcelain sintering: slow specimens were cooled inside the turned-off furnace; normal specimens were removed from the furnace and cooled in air at room temperature; and fast specimens were removed from the furnace at 910°C and cooled by compressed air for 10 s. Specimens were polished and flexural strength was measured in water at 37 °C (n=15). Maximum load at fracture was recorded, and equations for simple (monolayer) and composite (bilayer) structures were used to calculate the flexural strength. RESULTS were analyzed using one-way ANOVA (p<0.05) and Tukey test separately for each design.RESULTS: The results of one-way ANOVA were statistically significant only for the PB group. The post-hoc Tukey test showed the highest flexural strength for fast cooling and the lowest for slow cooling; the normal cooling was statistically similar to both.CONCLUSIONS: Cooling methods affected only the flexural strength of bilayer specimens with porcelain on low surface (under tension) when the slow cooling method was used. (AU)

• Processo FAPESP: 09/17735-8 - Efeito de diferentes taxas de resfriamento sobre a cerâmica feldspática de cobertura para infraestruturas em zircônia
• Beneficiário: Antonio Alves de Almeida Junior
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 10/05469-9 - Efeito de diferentes taxas de resfriamento sobre a cerâmica feldspática de cobertura para infra-estruturas em zircônia
• Beneficiário: Gelson Luis Adabo
• Modalidade de apoio: Auxílio à Pesquisa - Regular