title: Long-term sorption and solubility of bulk-fill and conventional resin-composites in water and artificial saliva.
abstract: OBJECTIVE
  To assess sorption and solubility of several bulk-fill and conventional resin-composites after one-year storage in water and artificial saliva (AS).
  
  
  METHODS
  Six bulk-fill (SureFil SDR, Venus Bulk Fill, X-tra base, Filtek Bulk Fill flowable, Sonic Fill, and Tetric EvoCeram Bulk Fill) and eight conventional resin-composites (Grandioso Flow, Venus Diamond Flow, XFlow, Filtek Supreme XTE, Grandioso, Venus Diamond, TPH Spectrum, and Filtek Z250) were tested. Disc shaped samples (n=5) were randomly immersed into distilled water and AS for one-year period and weighed at different time intervals. Data were analysed using repeated measures ANOVA, one-way ANOVA, and Tukey's post hoc test (α=0.05).
  
  
  RESULTS
  In water, all materials (with the exception of X-Flow) reached a stable mass within three months with a slow increase observed in AS up to one year. Sorption values in water and AS for most materials were not significantly different (p≥0.2). Sorption and solubility values in water ranged from (6.5 μg/mm(3) and -1.77 μg/mm(3) respectively) for X-tra base to (78.8 μg/mm(3) and 44.77 μg/mm(3) respectively) for X-Flow (p<0.005). Sorption of the polymer matrix in water ranged from 1.18% for XB to 9.95 % for XF.
  
  
  CONCLUSIONS
  Water sorption and solubility of resin-composites are material-dependent and highly affected by the filler loading and hydrophilicity of the resin matrix. BisEMA and UDMA-BisEMA based resins appeared to be more hydrophobic than BisGMA based systems. Water and AS, are generally comparable as storage media in terms of water sorption.
  
  
  CONCLUSIONS
  Bulk-fill materials and conventional resin-composites tested varied in terms of sorption and solubility but both were considered stable in longterm water storage. The composition of each material is critical and can affect the long-term clinical performance of either type of resincomposites.
authors.affiliation: School of Dentistry, The University of Manchester, Higher Cambridge Street, Mancheste, UK; Department of Oral and Maxillofacial Rehabilitation, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Ruwaida Z
authors.initials: RZ
authors.lastname: Alshali
authors.affiliation: Prosthodontic Department, University of Jordan, Amman, Jordan.
authors.forename: Nesreen A
authors.initials: NA
authors.lastname: Salim
authors.affiliation: School of Dentistry, The University of Manchester, Higher Cambridge Street, Mancheste, UK.
authors.forename: Julian D
authors.initials: JD
authors.lastname: Satterthwaite
authors.affiliation: School of Dentistry, The University of Manchester, Higher Cambridge Street, Mancheste, UK. Electronic address: nick.silikas@manchester.ac.uk.
authors.forename: Nick
authors.initials: N
authors.lastname: Silikas
mesh_terms: D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D012464:Saliva, Artificial / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D012464:Saliva, Artificial; D014867:Water; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane
keywords: Artificial saliva; Bulk-fill; Resin-composite; Solubility; Sorption; Water