title: Comparison of silorane and methacrylate-based composite resins on the curing light transmission.
abstract: The aim of this study was to investigate the influence of different composite resins - Filtek P90 (silorane-based composite) and Heliomolar (methacrylate-based composite) - on light transmission and decrease in Knoop hardness between the bottom and top of cured specimens. The irradiance of a light-curing unit (LCU) was measured with a power meter (Ophir Optronics; 900 mw/cm2) and spectral distributions were obtained using a spectrometer (USB 2000). Twenty standardized cylindrical specimens (2 mm thick x 7 mm diameter) of each composite resin were obtained by curing using the LCU for 40 s. Light energy transmission through the composite was calculated (n=10). The Knoop hardness number for each surface was recorded as the mean of 3 indentations. The difference in Knoop hardness between the top and bottom (DKH) of the same specimen was calculated (n=10). The irradiance of light that passed through Filtek P90 (272 mW/cm2) was not significantly greater than that the passed through Heliomolar (271 mW/cm2). The DKH of Filtek P90 (25%) was significantly higher than that of Heliomolar (12%). There was a greater degree of subsurface polymerization of the methacrylate-based composite compared to the silorane-based composite.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of North Paraná, Londrina, PR, Brazil. rdguiraldo@gmail.com
authors.forename: Ricardo Danil
authors.initials: RD
authors.lastname: Guiraldo
authors.forename: Simonides
authors.initials: S
authors.lastname: Consani
authors.forename: Rafael Leonardo Xediek
authors.initials: RL
authors.lastname: Consani
authors.forename: Sandrine Bittencourt
authors.initials: SB
authors.lastname: Berger
authors.forename: Wilson Batista
authors.initials: WB
authors.lastname: Mendes
authors.forename: Mário Alexandre Coelho
authors.initials: MA
authors.lastname: Sinhoreti
authors.forename: Lourenço
authors.initials: L
authors.lastname: Correr-Sobrinho
mesh_terms: D000180:Acrylic Resins; D003188:Composite Resins / Q000737:chemistry*; D003799:Dental Stress Analysis; D006244:Hardness; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008689:Methacrylates; D055620:Optical Phenomena; D058105:Polymerization; D011140:Polyurethanes; D062047:Silorane Resins; D012833:Siloxanes
chemical_list: D000180:Acrylic Resins; D003188:Composite Resins; C513708:Heliomolar; D008689:Methacrylates; D011140:Polyurethanes; D062047:Silorane Resins; D012833:Siloxanes; C555513:silorane composite resin