title: How light sources and distance of the light tip influence water sorption, solubility, and biaxial flexural strength of a composite resin.
abstract: This study evaluated the water sorption (WS), solubility (SL), and biaxial flexural strength (BFS) of a resin composite based on different polymerization units, storage permeants (distilled water and 75% ethanol), and distances between the light's tip and the composite resin. Using a stainless steel mold, 80 specimens were made and separated in two independent groups, according to the duration of storage (7 days or 60 days). The specimens were photocured using either a QTH or LED light (both used at 600 mW/cm2 for 40 seconds), with the light's tip guide either 0 mm or 2 mm from the surface of the resin. In general, the 75% ethanol produced higher WS and SL values but lower BFS values compared to water. Both distances influenced the WS and SL values, especially when 75% ethanol was used (p < 0.05), although neither distance affected BFS values (p > 0.05). For nearly all groups, the WS, SL, and BFS in different solvents and at different distances for photocuring of the tested resin were not affected by the curing light used.
authors.affiliation: Department of Prevention and Oral Rehabilitation, School of Dentistry, Federal University of Goias, Brazil.
authors.forename: Lawrence Gonzaga
authors.initials: LG
authors.lastname: Lopes
authors.forename: Beatriz Rodrigues
authors.initials: BR
authors.lastname: Moraes
authors.forename: Renata Magalhaes P
authors.initials: RM
authors.lastname: Souza
authors.forename: Alfeu da Veiga
authors.initials: Ada V
authors.lastname: Jardim Filho
authors.forename: Francine do Cuoto Lima
authors.initials: Fdo C
authors.lastname: Moreira
authors.forename: Roberto Elias
authors.initials: RE
authors.lastname: Campos
authors.forename: Joao Batista
authors.initials: JB
authors.lastname: de Souza
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects*; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D055117:Curing Lights, Dental; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D055115:Light-Curing of Dental Adhesives / Q000295:instrumentation / Q000379:methods*; D008422:Materials Testing; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry; D017155:Wettability
chemical_list: D003188:Composite Resins; D012997:Solvents; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate