title: Dual resin cement knoop hardness after different activation modes through dental ceramics.
abstract: This study investigated the influence of ceramic compositions on Knoop Hardness Number (KHN) immediately and 24 h after polymerization and the effect of activation modes on the KHN of a resin cement. Ten Panavia F 2.0 resin cement discs were activated either directly using curing light, or chemically without light, or through 1.2-thick ceramic discs. The following ceramics were evaluated: Duceram, Cergogold, IPS Empress, IPS Empress 2, Procera, Cercon, In Ceram Alumina and In Ceram Zirconia. The KHN was obtained immediately and after 24-h testing time. Two-way ANOVA and Tukey's test were performed for statistical analysis (p<0.05). Direct activation showed higher KHN than activation through ceramics and chemical activation for both immediate and 24-h post activation. The KHN for 24-h post activation time was higher than that of the immediate post activation time except for the direct activation mode. The glass and di-silicate based ceramics showed higher KHN than alumina- and zirconia-based ceramics, immediately and after 24-h. The reinforced and opaque ceramics had the lowest KHN. The ceramic composition resulted in light attenuation, lower polymerization and lower KHN, and the 24-h testing time promoted an improvement of KHN except for direct activation mode.
authors.affiliation: Department of Dental Materials and Restorative Dentistry, University of Uberaba, Uberaba, MG, Brazil. thiago.valentino@uniube.br
authors.forename: Thiago Assunção
authors.initials: TA
authors.lastname: Valentino
authors.forename: Gilberto Antonio
authors.initials: GA
authors.lastname: Borges
authors.forename: Luis Henrique
authors.initials: LH
authors.lastname: Borges
authors.forename: Jain
authors.initials: J
authors.lastname: Vishal
authors.forename: Luis Roberto Marcondes
authors.initials: LR
authors.lastname: Martins
authors.forename: Lourenço
authors.initials: L
authors.lastname: Correr-Sobrinho
mesh_terms: D000704:Analysis of Variance; D003776:Dental Porcelain / Q000737:chemistry* / Q000528:radiation effects; D006244:Hardness; D006245:Hardness Tests; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry* / Q000528:radiation effects; D055116:Self-Curing of Dental Resins; D018709:Statistics, Nonparametric
chemical_list: D019279:Resin Cements; D003776:Dental Porcelain