title: The effect of surface treatment on the Knoop hardness of Dicor.
abstract: One advantage cited for the use of Dicor over other ceramic materials is a reported Knoop hardness comparable to human enamel. However, when fabricating dental restorations, a Dicor glass-ceramic casting generally is subjected to several different surface treatments because of processing, esthetic, and functional requirements. Therefore, this study compared the Knoop hardness of Dicor specimens under three conditions: (1) cerammed, (2) cerammed and shaded, and (3) sectioned to reveal internal material. Knoop hardness differences between groups were significant (P less than or equal to .05). The cerammed surface was the hardest; it was harder than human enamel. Shaded specimens had a surface hardness comparable to dental porcelain. However, the internal glass-ceramic material, located beneath the shading porcelain and cerammed surface, had a Knoop hardness slightly higher than that of human enamel.
authors.affiliation: USAF Dental Investigation Service.
authors.forename: W P
authors.initials: WP
authors.lastname: Naylor
authors.forename: C A
authors.initials: CA
authors.lastname: Munoz
authors.forename: C J
authors.initials: CJ
authors.lastname: Goodacre
authors.forename: M L
authors.initials: ML
authors.lastname: Swartz
authors.forename: B K
authors.initials: BK
authors.lastname: Moore
mesh_terms: D000704:Analysis of Variance; D002516:Ceramics; D003776:Dental Porcelain; D006244:Hardness; D006245:Hardness Tests; D008422:Materials Testing
chemical_list: C047475:Dicor ceramic; D003776:Dental Porcelain