title: In vitro biocompatibility of denture relining materials.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the in vitro biocompatibility of denture relining materials using cell culture tests and a test for irritation mechanisms.
  
  
  BACKGROUND
  Denture relining materials contain non-reacted constituents that may leach out during use inducing local toxic or irritative effects.
  
  
  METHODS
  One chemically cured, four visible light cured and five dual-cured products were included. Cured test specimens were used for the filter diffusion test, and extracts of cured specimens were applied in the MTT and the irritation test using the hen's egg test-chorioallantoic membrane (HET-CAM) method.
  
  
  RESULTS
  Five of the tested materials were slightly or moderately cytotoxic in the filter diffusion test, and one product coated with a liner induced severe toxicity. Cell cultures incubated for 24 hour with the test samples were more damaged than those incubated for 2 hour. In the MTT test, extracts of nine of the 11 products induced cytotoxicity. No extracts showed irritation, whereas the coating and two bonding agents tested were strong irritants.
  
  
  CONCLUSIONS
  Most of the tested materials contained water soluble, toxic substances that leach out of the products and that some time was needed to obtain cytotoxic amounts of the leachables. Many dental materials elicit cytotoxic response, but this does not necessarily reflect the long-term risk for adverse effects as the oral mucosa is generally more resistant to toxic substances than a cell culture.
authors.affiliation: Nordic Institute of Dental Materials, Haslum, Norway. jon.dahl@niom.no
authors.forename: Jon E
authors.initials: JE
authors.lastname: Dahl
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Frangou-Polyzois
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Polyzois
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003764:Dental Materials / Q000633:toxicity*; D003823:Denture Rebasing / Q000009:adverse effects*; D006801:Humans; D008422:Materials Testing / Q000379:methods*; D051379:Mice
chemical_list: D003764:Dental Materials