title: Mechanical properties of light-cured composite resins cured through filters that simulate enamel.
abstract: The light-attenuating effects of enamel on the mechanical properties of light-cured composite resins were evaluated using simple experimental filters. Three filters were designed to simulate the light transmittance characteristics of 0.5, 1.0, and 1.5 mm thick human enamel. The Knoop hardness numbers (KHN) and the elastic modulus in transverse tests for twelve shades of three light-cured composite resins were examined. These resins were cured either using direct irradiation with a light source, or indirect irradiation through one of the filters. The attenuations of light by 0.5, 1.0, and 1.5 mm thick enamel filter were 45%, 67% and 81% in the 430 nm-550 nm wavelength region, respectively. For all materials, KHN and the elastic modulus of specimens irradiated through filters were significantly lower than those irradiated directly. The results suggest that the light-attenuating effect of enamel reduces the mechanical properties of light-cured resin, and may cause poor clinical longevity of restorations.
authors.affiliation: Department of Biomaterials Science, Kagoshima University Dental School, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Arikawa
authors.forename: Takahito
authors.initials: T
authors.lastname: Kanie
authors.forename: Koichi
authors.initials: K
authors.lastname: Fujii
authors.forename: Keita
authors.initials: K
authors.lastname: Fukui
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Homma
mesh_terms: D000465:Algorithms; D003116:Color; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D003743:Dental Enamel / Q000033:anatomy & histology; D004548:Elasticity; D005374:Filtration / Q000295:instrumentation*; D006244:Hardness; D006801:Humans; D008027:Light; D008422:Materials Testing; D055095:Optics and Photonics / Q000295:instrumentation; D013223:Statistics as Topic; D013499:Surface Properties
chemical_list: D003188:Composite Resins; C083468:Lite-fil CR; C074741:Silux Plus; C039734:Durafill