title: Water sorption and solubility of dentin bonding agents light-cured with different light sources.
abstract: OBJECTIVE
  The aim of this study was to compare water sorption (WS) and solubility (WSB) of different dentin bonding agents (DBA) as regards classification and light-activation system. The null hypotheses were: (1) there is no difference among DBA with respect to water sorption and solubility; (2) there is no effect of light-curing source on water sorption and solubility of DBA.
  
  
  METHODS
  The tested materials were: three-step etch-and-rinse (ScotchBond multi-purpose and Heliobond-control groups), two-step etch-and-rinse (Excite, Adper Single Bond, Adper Single Bond 2), self-etching (Adhse) and all-in-one (Xeno III) systems. For each material, six specimens were prepared (0.8mmx5.5mm) for each light-activation device: halogen lamp (control) or light-emitting diodes (LED). They were transferred to desiccators until a constant mass was obtained (m(1)), subsequently immersed in deionized water until no alteration was obtained (m(2)). Following, the specimens were reconditioned to constant mass in desiccators (m(3)). The volume (V) of each specimen was calculated (mm(3)). WS and WSB were determined using the equations (m(2)-m(3)/V) and (m(3)-m(1)/V), respectively. Data were subjected to one-way analysis of variance and Tukey test (p<0.05). The influence of photo-activation units was analyzed by t-test.
  
  
  RESULTS
  Higher values of WS and WSB were observed for the two-step etch-and-rinse and all-in-one systems. The employed light-activation unit also affected the tested characteristics. Thus, the anticipated null hypotheses were rejected.
  
  
  CONCLUSIONS
  Simplified systems were more susceptible to water adverse and they may become more prone to degradation over time regardless of the type of light-activation source.
authors.affiliation: Department of Restorative Dentistry, University North of Paraná (UNOPAR), Londrina, PR, Brazil.
authors.forename: Hebert Samuel Carafa
authors.initials: HS
authors.lastname: Fabre
authors.forename: Samuel
authors.initials: S
authors.lastname: Fabre
authors.forename: Daniela Francisca Gigo
authors.initials: DF
authors.lastname: Cefaly
authors.forename: Marcela Rocha
authors.initials: MR
authors.lastname: de Oliveira Carrilho
authors.forename: Fernanda Cristina Pimentel
authors.initials: FC
authors.lastname: Garcia
authors.forename: Linda
authors.initials: L
authors.lastname: Wang
mesh_terms: D000042:Absorption; D000179:Acrylates / Q000737:chemistry; D000180:Acrylic Resins / Q000737:chemistry; D000327:Adsorption; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D017220:Dentin-Bonding Agents / Q000737:chemistry* / Q000528:radiation effects; D003890:Desiccation; D006801:Humans; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012995:Solubility; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000179:Acrylates; D000180:Acrylic Resins; C489662:AdheSE cement; D017220:Dentin-Bonding Agents; C420130:Excite cement; D008689:Methacrylates; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C487957:Xeno III; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate; C040415:heliobond