title: Effect of polymorphism of SiO2 addition on mechanical properties of Feldspathic porcelains.
abstract: The present study aimed to investigate the effects of SiO2 polymorphism on the mechanical properties of feldspathic porcelains. Seven kinds of experimental feldspathic porcelains were prepared using chemical reagents; three types of low-fusing feldspathic glasses and four types of two-phase porcelains by adding 10 or 20 mass% of fused silica (T-F) or cristobalite (T-C). Flexural strength and fracture toughness of these porcelains were evaluated. Flexural strengths of two-phase porcelains did not show any significant increase when compared with those of single-phase glasses. On the other hand, fracture toughnesses of porcelains with cristobalite showed a significant increase when compared with those of single-phase glasses. Circumferential cracks were observed in the porcelains with cristobalite. These results suggested that cristobalite could strengthen fracture toughness of feldspathic porcelains, but not flexural strength.
authors: General Dentistry Department of Comprehensive Oral Health Care, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. ryo.gend@tmd.ac.jp
authors: Ryo
authors: R
authors: Tokunaga
authors: Hidekazu
authors: H
authors: Takahashi
authors: Naohiko
authors: N
authors: Iwasaki
authors: Masahiro
authors: M
authors: Kobayashi
authors: Kenichi
authors: K
authors: Tonami
authors: Norimasa
authors: N
authors: Kurosaki
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry; D003460:Crystallization; D003776:Dental Porcelain / Q000737:chemistry*; D004548:Elasticity; D005898:Glass / Q000737:chemistry; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D019563:Mechanics; D008855:Microscopy, Electron, Scanning; D018583:Pliability; D011188:Potassium / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D000538:Aluminum Silicates; D002254:Carbonates; D017680:Potassium Compounds; D003776:Dental Porcelain; C016447:feldspar; C005686:sodium carbonate; D000536:Aluminum Hydroxide; D012822:Silicon Dioxide; C037593:potassium carbonate; D011188:Potassium