Mechanical properties and porosity of dental glass-ceramics hot-pressed at different temperatures

Materials Research

Carla Castiglia Gonzaga²  Paulo Francisco Cesar²  Cristina Yuri Okada²  Catia Fredericci¹  Flávio Beneduce Neto¹  Humberto Naoyuki Yoshimura¹ 

[1] ,University of São Paulo School of Dentistry Department of Biomaterials and Oral BiochemistrySão Paulo SP ,Brazil

关键词: dental glass-ceramics;    injection temperature;    mechanical properties;    porosity;   

DOI  :  10.1590/S1516-14392008000300012

来源: SciELO

【 摘 要 】

The objective of this work was to evaluate biaxial-flexural-strength (σf), Vickers hardness (HV), fracture toughness (K Ic), Young's modulus (E), Poisson's ratio (ν) and porosity (P) of two commercial glass-ceramics, Empress (E1) and Empress 2 (E2), as a function of the hot-pressing temperature. Ten disks were hot-pressed at 1065, 1070, 1075 and 1080 °C for E1; and at 910, 915, 920 and 925 °C for E2. The porosity was measured by an image analyzer software and s f was determined using the piston-on-three-balls method. K Ic and HV were determined by an indentation method. Elastic constants were determined by the pulse-echo method. For E1 samples treated at different temperatures, there were no statistical differences among the values of all evaluated properties. For E2 samples treated at different temperatures, there were no statistical differences among the values of σf, E, and ν, however HV and K Ic were significantly higher for 910 and 915 °C, respectively. Regarding P, the mean value obtained for E2 for 925 °C was significantly higher compared to other temperatures.

【 授权许可】

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