Assessment of polymerization contraction stress of three composite resins

Dent Mater. 2008 May;24(5):681-5. doi: 10.1016/j.dental.2007.06.031. Epub 2007 Aug 31.

Abstract

Objectives: The purpose of this study was to measure the development of contraction stress of three composite resin restorative materials during photo-polymerization: a micro-hybrid composite (Filtek Z250, 3M ESPE, St. Paul, MN, USA); a nano-filled composite (Filtek Supreme, 3M ESPE, St. Paul, MN, USA); and a low-shrinkage composite (AElite LS, Bisco Inc., Schaumburg, IL, USA).

Methods: Curing shrinkage stress was measured using a stress-analyzer. Composites were polymerized with a halogen-curing unit (VIP, Bisco Inc., Schaumburg, IL, USA) for 40 s. The contraction force (N) generated during polymerization was continuously recorded for 150 s after photo-initiation. Contraction stress (MPa) was calculated at 20, 40, 60 and 150 s. Data were statistically analyzed.

Results: The low-shrinkage composite AElite LS exhibited the lowest stress values compared to other materials (p<0.05). Statistical analysis did not show significant differences between Filtek Z250 and Filtek Supreme.

Significance: The low-shrinkage composite showed lower contraction stress than micro-hybrid and nano-filled composite. Ideally, non-shrinking resins would represent the ultimate solution to overcome polymerization contraction and stress-related problems.

MeSH terms

  • Composite Resins / chemistry*
  • Composite Resins / radiation effects
  • Dental Materials / chemistry*
  • Dental Materials / radiation effects
  • Dental Stress Analysis / instrumentation
  • Humans
  • Light
  • Materials Testing
  • Polymers / chemistry
  • Polymers / radiation effects
  • Stress, Mechanical
  • Temperature
  • Time Factors

Substances

  • Aelite LS
  • Composite Resins
  • Dental Materials
  • Filtek Supreme
  • Filtek Z250
  • Polymers