title: Cytotoxic effects of dental composites, adhesive substances, compomers and cements.
abstract: OBJECTIVE
  Although research interest in biocompatibility of dental materials has been increasing, findings are frequently controversial and non-harmonized experimental approaches often lead to the production of contradictory results. The aim of this study was to compare the cytotoxic effects of six different light-cured dental composites, one compomer, one advanced glass-ionomer, two glass-ionomer cements, two zinc phosphate cements, one calcium hydroxide liner, one composite cement and one carboxylate cement with the same standardized cell-culture system. Two composites, one compomer and one advanced glass-ionomer were also tested in combination with the appropriate bonding substances and surface primers.
  
  
  METHODS
  Specimens were added to the cultures immediately after production or after preincubation for 1, 2 or 7 days or 6 weeks under cell-culture conditions. Specimens were incubated with L-929 fibroblasts for 72 h and cell numbers determined by flow cytometry.
  
  
  RESULTS
  All freshly prepared composite materials were cytotoxic. These effects diminished with increased preincubation times and were not significant after 7 days. Combinations of composites and bonding substances were still cytotoxic after preincubation for 7 days, but not after 6 weeks. Combinations of compomers and bonding substances demonstrated stronger toxicity than composites, although these effects were reduced earlier during preincubation. Glass-ionomer and phosphate cements showed similar effects to the composites with the exception of carboxylate cement, which demonstrated severe and persistent effects even after 6 weeks' preincubation. Together, our data provide evidence that all dental materials tested are cytotoxic immediately after production and that these effects are reduced after different preincubation periods in most cases.
  
  
  CONCLUSIONS
  Tested with a standardized cell-culture system, differences in toxicological potency between various commonly used dental materials were observed. Cytotoxicity data from standardized protocols should form the basis of screening the cytotoxic effects of new materials.
authors.affiliation: Institute of General and Experimental Pathology, University of Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Schedle
authors.forename: A
authors.initials: A
authors.lastname: Franz
authors.forename: X
authors.initials: X
authors.lastname: Rausch-Fan
authors.forename: A
authors.initials: A
authors.lastname: Spittler
authors.forename: T
authors.initials: T
authors.lastname: Lucas
authors.forename: P
authors.initials: P
authors.lastname: Samorapoompichit
authors.forename: W
authors.initials: W
authors.lastname: Sperr
authors.forename: G
authors.initials: G
authors.lastname: Boltz-Nitulescu
mesh_terms: D000269:Adhesives / Q000633:toxicity; D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials / Q000633:toxicity*; D002126:Calcium Hydroxide / Q000633:toxicity; D003188:Composite Resins / Q000633:toxicity*; D003736:Dental Cavity Lining; D003738:Dental Cements / Q000633:toxicity*; D005899:Glass Ionomer Cements / Q000633:toxicity; D007739:L Cells / Q000187:drug effects; D008422:Materials Testing; D051379:Mice; D011076:Polycarboxylate Cement / Q000633:toxicity; D018709:Statistics, Nonparametric; D013997:Time Factors; D018675:Toxicity Tests / Q000592:standards; D015036:Zinc Phosphate Cement / Q000633:toxicity
chemical_list: D000269:Adhesives; D001672:Biocompatible Materials; D003188:Composite Resins; D003738:Dental Cements; D005899:Glass Ionomer Cements; D011076:Polycarboxylate Cement; D015036:Zinc Phosphate Cement; D002126:Calcium Hydroxide