title: Microhardness and Young's modulus of a bonding resin cured with different curing units.
abstract: This study evaluated the microhardness and Young's modulus of a photocurable bonding resin, Clearfil SE Bond (SE), cured with four curing units at different distances. The curing units used were: Candelux (Quartz-tungsten halogen), Lux-O-Max (Blue light emitting diode), Arc-light (Plasma-arc), and Rayblaze (Metal halide). Discs of bonding resin were prepared using vinyl molds and were photocured at the top surface with light tip at three different distances (contact, 2 and 4 mm). After 24 hours of storage in water at 37 degrees C, the specimens were sectioned into halves, embedded in epoxy resin, and polished. The microhardness and Young's modulus of this bonding resin were measured using a nanoindentation tester. Six specimens were prepared for each group. The data was statistically analyzed using two-way ANOVA test and Tukey multiple comparison test (p < 0.01). The microhardness of SE was affected by light source and distance, as was Young's modulus. Candelux and Rayblaze presented the highest hardness and Young's modulus results. Both properties presented high values when the curing unit tip was maintained in contact with the irradiated surface. Increasing the distance between the curing unit tip and the irradiated surface decreased the hardness and Young's modulus of SE.
authors.affiliation: Section of Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Faculty of Dentistry, Tokyo Medical and Dental University, 5-45 Yushima, 1-Chome, Bunkyo-ku, Tokyo 113-5489, Japan. monica.ope@tmd.ac.jp
authors.forename: Monica
authors.initials: M
authors.lastname: Yamauti
authors.forename: Toru
authors.initials: T
authors.lastname: Nikaido
authors.forename: Masaomi
authors.initials: M
authors.lastname: Ikeda
authors.forename: Masayuki
authors.initials: M
authors.lastname: Otsuki
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000704:Analysis of Variance; D003748:Dental Equipment; D004548:Elasticity / Q000528:radiation effects; D006219:Halogens; D006244:Hardness / Q000528:radiation effects; D008027:Light; D008422:Materials Testing; D019279:Resin Cements / Q000528:radiation effects; D012666:Semiconductors; D018709:Statistics, Nonparametric; D013674:Technology, Dental / Q000295:instrumentation; D014978:Xenon
chemical_list: C438313:Clearfil SE Bond; D006219:Halogens; D019279:Resin Cements; D014978:Xenon