[Properties of GI-II glass/alumina composite infiltrated with GI-II tinted infiltration glass].
OBJECTIVE
The purpose of this study was to determine the thermal, mechanical properties and density of the composite infiltrated with GI-II tinted infiltration glass.


METHODS
The bar-shaped aluminum oxide and glass/alumina composite specimens with the size of 20 mm x 5 mm x 5 mm were prepared, with two free-end surfaces perpendicular to the long axis of the specimens and parallel to each other. The thermal expansion curves were obtained on a TMA2940 thermal analyzer with heating rate of 5 degrees C/min and temperature range of 25 degrees C to 1000 degrees C. The bar-shaped specimens with the size of 25 mm x 5 mm x 2 mm were fabricated and employed to test the density using Archmede's method. The flexural strength, elastic modulus were measured by means of 3-point bending test with the same specimens. The fractured specimens were indented with Vicker's diamond pyramid under load of 49 N for 15 seconds to determine the hardness and indentation fracture toughness.


RESULTS
The thermal expansion coefficient of the glass/alumina composite was 7.620 x 10(-6) degrees C-1 (25-500 degrees C), which was higher than that of Vitadur alpha veneering porcelain. The 3-poit flexural strength, elastic modulus, Vicker's hardness, indentation fracture toughness and density were 389.6 MPa, 92 GPa, 9.409 GPa, 3.2425 MNm-3/2 and 3.662 g/cm3 respectively.


CONCLUSIONS
The thermal expansion of the GI-II glass/alumina composite is compatible with that of Vitadur alpha veneering porcelain, and the material could meet the strength demands for clinical use.
Han
Xiaoli
X
West China College of Stomatology, Sichuan University.
Liao
Yunmao
Y
Chao
Yonglie
Y
D000537:Aluminum Oxide / Q000737:chemistry*; D002516:Ceramics; D003764:Dental Materials; D003776:Dental Porcelain / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D013718:Tensile Strength; D044366:Transition Temperature
D003764:Dental Materials; D003776:Dental Porcelain; D000537:Aluminum Oxide