Effect of water exposure on the fracture toughness and flexure strength of a dental glass
| Autor: | Urs C. Belser, Isabelle Denry, H. W. Anselm Wiskott, Susanne S. Scherrer |
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| Rok vydání: | 2001 |
| Předmět: |
Ceramics
Toughness Hot Temperature Time Factors Materials science Potassium Compounds Surface Properties Statistics as Topic Bending Dental Materials Fracture toughness Hardness Indentation Materials Testing Humans General Materials Science Ceramic Composite material Pliability General Dentistry Acetic Acid Weibull distribution Chemical resistance Air Water Dental Porcelain Dental Polishing Mechanics of Materials visual_art Fracture (geology) visual_art.visual_art_medium Aluminum Silicates Glass Stress Mechanical |
| Zdroj: | Dental Materials. 17:367-371 |
| ISSN: | 0109-5641 |
| DOI: | 10.1016/s0109-5641(01)00002-1 |
| Popis: | Objectives: The low fusing dental glass (Duceram LFC) has been advertised as presenting a superior chemical resistance and augmented strength after 16 h exposure to water or 4% acetic acid. The purpose of this study was to evaluate the effect of prolonged exposure to water on two mechanical properties (fracture toughness and flexure strength) of LFC. Methods: Disks and bars were mirror polished and annealed prior to aging in: (1) air (control), (2) water for 24 h at 80°C and (3) water for 8 weeks at 80°C. Fracture toughness (KIc) was determined by indentation fracture (IF) and indentation strength (IS) using a 19.6 N Vickers indentation load. Flexure strength values were obtained from three-point bending at 0.1 mm/min. Statistical analysis was performed using the Weibull distribution, Tukey and Bartlett tests (P Results: Both techniques (IS and IF) showed a significant improvement in the K of Duceram LFC after 8 weeks in water (0.88 and 1.14 MPa m0.5) as opposed to the 24-h values both in water and air (0.77–0.78 MPa m0.5). However, for flexure strength the Weibull characteristic (S0) and the m parameter did not change significantly with water storage (S0=90–100 MPa, Weibull m =7–8). Significance: The increase in toughness of Duceram LFC after aging in water is an interesting and favorable observation for a restorative material exposed to the oral environment. Nevertheless, in comparison with other contemporary ceramics, the toughness of this LFC remains in the range of soda-lime-glass or classic feldspar porcelains. |
| Databáze: | OpenAIRE |
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