title: Influence of temperature on volumetric shrinkage and contraction stress of dental composites.
abstract: OBJECTIVE
  To test the influence of temperature on contraction stress and volumetric shrinkage of Clearfil AP-X, Venus Diamond, Premise and Filtek Z250.
  
  
  METHODS
  Volumetric shrinkage measurements were carried out using mercury dilatometry, while a constraint tensilometer set-up was used for the measurement of contraction stress. Measurements were carried out with a composite temperature of 23, 30, 37, and 44°C.
  
  
  RESULTS
  Volumetric shrinkage increases with higher temperature. Premise and Venus Diamond show lower volumetric shrinkage than Clearfil AP-X and Filtek Z250. Clearfil AP-X shows the highest contraction stress which slightly increases with higher temperatures. The other composites only show an increase in contraction stress between 23 and 30°C.
  
  
  CONCLUSIONS
  Heating of dental composites results in a higher volumetric shrinkage. However, the contraction stress does not change significantly due to increased temperature above 30°C.
authors.affiliation: Department of Dental Materials Sciences, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, The Netherlands. Electronic address: l.jongsma@acta.nl.
authors.forename: Leontine A
authors.initials: LA
authors.lastname: Jongsma
authors.affiliation: Department of Dental Materials Sciences, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, The Netherlands.
authors.forename: Cees J
authors.initials: CJ
authors.lastname: Kleverlaan
mesh_terms: D003188:Composite Resins / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation*; D008422:Materials Testing; D008689:Methacrylates; D013696:Temperature
chemical_list: C112828:Clearfil AP-X; D003188:Composite Resins; C444701:Filtek Z250; D008689:Methacrylates; C488393:Venus (composite resin); C507210:premise composite resin
keywords: Composite pre-heating; Contraction stress; Resin composite; Temperature; Volumetric shrinkage