title: Influence of light irradiation on Vickers hardness of dual-cure cement polymerized under restorations.
abstract: This study evaluated, by measuring Vickers hardness (Hv), the effects of these factors on the degree of polymerization of dual-cure cement (Panavia F2.0) placed under a restoration: light transmission property of restoratives materials, distance from the directly irradiated surface, and elapsed time after light irradiation. Two materials were used for the restoration: silver-palladium-copper-gold alloy (Alloy) versus zirconia (ZR). Restorations were cemented on bovine enamel by dual-cure cement. At 30 min, 2 h, 6 h, 1 day, and 1 week after definitive irradiation, Hv values at the enamel side of cement were evaluated at three measuring points: two points at the left and right margins and one point at the center. Data were analyzed by two-way ANOVA with Bonferroni correction (α=0.05). With the Alloy restoration, Hv value at the center was significantly lower than those at the margins at 30 min after irradiation. For both Alloy and ZR restorations, Hv value at each measuring point continued to increase significantly up to 6 h.
authors.affiliation: Fixed Prosthetic Clinic, Kagoshima University Medical and Dental Hospital, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan.
authors.forename: Daisaku
authors.initials: D
authors.lastname: Shiomuki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Minami
authors.forename: Takuo
authors.initials: T
authors.lastname: Tanaka
authors.forename: Shiro
authors.initials: S
authors.lastname: Suzuki
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects; D003722:Dental Alloys; D003793:Dental Restoration, Permanent; D006244:Hardness / Q000528:radiation effects*; D008027:Light; D008422:Materials Testing; D058105:Polymerization / Q000528:radiation effects*; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D018709:Statistics, Nonparametric; D013997:Time Factors; D015040:Zirconium
chemical_list: C120982:Ag-Pd-Cu-Au alloy; D003188:Composite Resins; C095997:DCR cement; D003722:Dental Alloys; C438843:Panavia-Fluoro; D019279:Resin Cements; D015040:Zirconium; C028541:zirconium oxide