Publication Date:
2011-05-28
Description:
Development of new joining glasses tailored to layered all-ceramic dental restoration systems is described. These new glasses were developed to meet the requirements for dental restorations, including coefficient of thermal expansion (CTE) matching in the 100°–500°C range, wetting characteristics, densification temperature for fritted glass layers, radio-opacity, color, and lead-free composition. Glasses in the BaO–Al 2 O 3 –Na 2 O–B 2 O 3 –SiO 2 system were investigated for their biocompatibility, chemical stability, and suitable calculated glass transition temperature ( T g ), and dilatometric softening point ( T d ). Appen additivity factors and Fluegal's database were used to estimate CTE, T g , T d , and E (elastic modulus) and select compositions in the CTE range 6.00 × 10 −6 –10.4 × 10 −6 /K for application to common dental alumina and zirconia ceramic systems. A sol–gel approach was used to produce homogenous glass precursors covering a wide range of compositions. Melting, firing, and quenching the compositions were required to form dense, uniform, transparent layers.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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