title: Depth of cure and hardness of an indirect composite polymerized with three laboratory curing units.
abstract: This study determined the hardness and curing depth of a light-activated indirect composite polymerized with three laboratory light-polymerizing units for the purpose of comparing the curing performance of the three units. A light-activated composite material for indirect application (Vita Zeta) was polymerized with three light-polymerizing units equipped with the following light sources: 1) one halogen lamp and two fluorescent lamps (alpha-Light II); 2) three halogen lamps (Twinkle HLG); and 3) one metal halide lamp (Twinkle LI). Knoop hardness and curing depth were determined for groups of five specimens using standardized testing methods. The results were compared using analysis of variance (ANOVA) and Scheffé's S intervals (alpha = 0.05). The Knoop hardness number (KHN) generated with the halogen-fluorescent unit (12.5 KHN) was significantly (P < 0.05) lower than those produced by the halogen unit (13.9 KHN) and the metal halide unit (14.2 KHN). Of the three units, the halogen-fluorescent unit exhibited the lowest depth of cure. Both the hardness and curing depth of the composite were influenced by the laboratory polymerizing units employed.
authors.affiliation: Department of Specialized Dentistry, Nagasaki University Hospital of Medicine and Dentistry, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Tanoue
authors.forename: Mahoko
authors.initials: M
authors.lastname: Murakami
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Koizumi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Atsuta
authors.forename: Hideo
authors.initials: H
authors.lastname: Matsumura
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000528:radiation effects*; D003748:Dental Equipment; D005453:Fluorescence; D006219:Halogens; D006244:Hardness; D008027:Light; D008422:Materials Testing; D008670:Metals; D044367:Phase Transition; D013674:Technology, Dental; D014978:Xenon
chemical_list: D003188:Composite Resins; D006219:Halogens; D008670:Metals; C509999:Vita Zeta LC; D014978:Xenon