title: Genotoxic biomonitoring of flowable and non-flowable composite resins in peripheral blood leukocytes.
abstract: OBJECTIVE
  Composite restorative materials represent one of the most important groups of materials in contemporary dental practice. However, their incomplete polymerization may lead to monomer-induced genotoxicity. The objective of this study was to evaluate the genotoxicity of three flowable (Filtek Supreme XT Flow, Tetric EvoFlow, Gradia Direct Flo) and three non-flowable dental composite materials (Filtek Z250, Tetric EvoCeram, Gradia Direct Posterior).
  
  
  METHODS
  Genotoxicity assessment of composite materials was carried out in vitro in human peripheral blood leukocytes using the alkaline single-cell gel electrophoresis technique (comet assay). Prepared materials were eluted in saline solution for 1 h, 1 day and 5 days. Thereafter leukocyte cultures were treated with different concentrations of eluates obtained from each of the tested dental composite materials. Kruskall-Wallis non-parametric test was used for statistical analysis (p < 0.05).
  
  
  RESULTS
  The tested materials did not show genotoxic effects after exposure of leucocytes to 1 h eluates. Culture treated with 1 day eluates of all tested materials, only at a highest concentration (10(-2)), affected the measured cytogenetic parameters. Of all tested materials, only Filtek Z250 and Filtek Supreme XT Flow did not exhibit a genotoxic effect in cultures that were under the influence of 5 day eluates.
  
  
  CONCLUSIONS
  Tested materials exhibited limited genotoxic activity in peripheral blood leukocytes. Since the effect was observed only in leukocyte cultures treated by 1-day eluates at the highest concentration (10(-2)) and it decreases in cultures exposed to 5 day eluates, it should not pose a significant risk to the human genome.
authors.affiliation: Study of Dental Medicine, School of Medicine, University of Split, Split, Croatia. atadin@mefst.hr
authors.forename: Antonija
authors.initials: A
authors.lastname: Tadin
authors.forename: Danijela
authors.initials: D
authors.lastname: Marovic
authors.forename: Nada
authors.initials: N
authors.lastname: Galic
authors.forename: Alice
authors.initials: A
authors.lastname: Milevoj
authors.forename: Ivana
authors.initials: I
authors.lastname: Medvedec Mikic
authors.forename: Davor
authors.initials: D
authors.lastname: Zeljezic
mesh_terms: D020552:Comet Assay; D003188:Composite Resins / Q000378:metabolism*; D004784:Environmental Monitoring; D007962:Leukocytes / Q000378:metabolism*; D009153:Mutagens / Q000633:toxicity*
chemical_list: D003188:Composite Resins; D009153:Mutagens