title: Effect of curing mode on the hardness of dual-cured composite resin core build-up materials.
abstract: This study evaluated the Knoop Hardness (KHN) values of two dual-cured composite resin core build-up materials and one resin cement exposed to different curing conditions. Two dual-cured core build-up composite resins (LuxaCore-Dual, DMG; and FluoroCore2, Dentsply Caulk), and one dual-cured resin cement (Rely X ARC, 3M ESPE) were used in the present study. The composite materials were placed into a cylindrical matrix (2 mm in height and 3 mm in diameter), and the specimens thus produced were either light-activated for 40 s (Optilux 501, Demetron Kerr) or were allowed to self-cure for 10 min in the dark (n = 5). All specimens were then stored in humidity at 37 degrees C for 24 h in the dark and were subjected to KHN analysis. The results were submitted to 2-way ANOVA and Tukey's post-hoc test at a pre-set alpha of 5%. All the light-activated groups exhibited higher KHN values than the self-cured ones (p = 0.00001), regardless of product. Among the self-cured groups, both composite resin core build-up materials showed higher KHN values than the dual-cured resin cement (p = 0.00001). LuxaCore-Dual exhibited higher KHN values than FluoroCore2 (p = 0.00001) when they were allowed to self-cure, while no significant differences in KHN values were observed among the light-activated products. The results suggest that dual-cured composite resin core build-up materials may be more reliable than dual-cured resin cements when curing light is not available.
authors.affiliation: Department of Operative Dentistry, School of Dentistry, University of Guarulhos, SP, Brazil.
authors.forename: César Augusto Galvão
authors.initials: CA
authors.lastname: Arrais
authors.forename: Aline de Cerqueira
authors.initials: Ade C
authors.lastname: Kasaz
authors.forename: Luís Gustavo Barrote
authors.initials: LG
authors.lastname: Albino
authors.forename: José Augusto
authors.initials: JA
authors.lastname: Rodrigues
authors.forename: Andre Figueiredo
authors.initials: AF
authors.lastname: Reis
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D055117:Curing Lights, Dental; D006245:Hardness Tests; D055115:Light-Curing of Dental Adhesives / Q000379:methods*; D008422:Materials Testing; D011176:Post and Core Technique / Q000295:instrumentation; D019279:Resin Cements / Q000737:chemistry* / Q000528:radiation effects; D055116:Self-Curing of Dental Resins / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D003188:Composite Resins; D019279:Resin Cements