title: Influence of dietary simulating solvents on the viscoelasticity of temporary soft lining materials.
abstract: BACKGROUND
  Clinical changes in the viscoelasticity of temporary soft lining materials are characterized by a more rapid and increased reduction in compliance than is seen after in vitro immersion. A possible explanation for these differences is a solvent effect, acting clinically to encourage the loss of ethanol and plasticizer. Dietary solvents have been suggested as likely agents.
  
  
  OBJECTIVE
  This study examined the effect of immersion in dietary simulating solvents on the viscoelasticity of temporary soft lining materials, with a view to formulating more clinically relevant immersion regimes used in the evaluation of these materials.
  
  
  METHODS
  Four temporary soft lining materials were immersed in distilled water and solutions chosen to simulate dietary solvents. Changes in viscoelasticity over time were recorded with a penetrometer, modified to record creep strain and strain during recovery.
  
  
  RESULTS
  All immersion solutions caused a significant reduction in compliance values of each material over time (P <.05). However, only heptane and corn oil immersants produced the rapid and increased reduction in compliance that is evident clinically. Changes in elastic recovery were less pronounced.
  
  
  CONCLUSIONS
  Results of this study offer support to a dietary source of solvent acting to effect clinical changes in the viscoelasticity of temporary soft lining materials.
authors.affiliation: The Dental School, University of Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom. n.j.a.jepson@ncl.ac.uk
authors.forename: N J
authors.initials: NJ
authors.lastname: Jepson
authors.forename: J T
authors.initials: JT
authors.lastname: McGill
authors.forename: J F
authors.initials: JF
authors.lastname: McCabe
mesh_terms: D000704:Analysis of Variance; D003822:Denture Liners; D003833:Denture, Partial, Temporary; D004032:Diet; D004548:Elasticity / Q000187:drug effects; D006801:Humans; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012997:Solvents / Q000494:pharmacology*; D014783:Viscosity / Q000187:drug effects
chemical_list: D012997:Solvents