title: The effect of surface roughness on the Weibull distribution of porcelain strength.
abstract: The purpose of the present study was to test the hypothesis that glazing will affect the Weibull modulus or the mean flexural strength of dental porcelain. Four groups (n = 30) of specimens were prepared from feldspathic body porcelain (Vita VMK 68). The specimens were tested in groups: original glazed condition (control), and after grinding separately with 1,000-grit, 600-grit, and 100-grit silicon carbide abrasive. A three-point flexure test was undertaken for each specimen. The flexural strength of porcelain and the Weibull modulus were then obtained using a computer program and load-to-failure data. Flexural strength decreased as surface roughness increased, and the differences were significant (p < 0.05), as determined by Tukey's multiple range test, except between the 600-grit group and the 100-grit group. The Weibull modulus of the glazed group was the largest (16.3), and the surface roughness was found to influence the Weibull modulus.
authors.affiliation: Department of Fixed Prosthodontics, School of Dental Medicine, Tsurumi University, Tsurumi-ku, Yokohama, Kanagawa, Japan. nakamura-y@tsurumi-u.ac.jp
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Satoru
authors.initials: S
authors.lastname: Hojo
authors.forename: Hideaki
authors.initials: H
authors.lastname: Sato
mesh_terms: D003722:Dental Alloys; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D016018:Least-Squares Analysis; D008422:Materials Testing; D018583:Pliability; D018709:Statistics, Nonparametric; D013499:Surface Properties; D016019:Survival Analysis
chemical_list: D003722:Dental Alloys; D003776:Dental Porcelain; C047040:Vita VMK 68