title: Effect of light curing type on cytotoxicity of dentine-bonding agents.
abstract: OBJECTIVE
  To compare the cytotoxic effects of dentine-bonding agents (DBAs) polymerized with two different curing units at 24 h and 72 h on L-929 cells.
  
  
  METHODS
  Disc-shaped test samples of light-activated DBAs were prepared according to manufacturers' instructions and cured with either conventional quartz tungsten halogen or light-emitting diode light curing units (LCUs). After curing, the samples were transferred into a culture medium for 24 h. Eluates were obtained and pipetted onto L-929 mouse fibroblast cultures (3 x 10(4) cells per well), incubated for evaluation after 24 and 72 h. After both incubation periods, measurements were performed by an dimethylthiazol diphenyltetrazolium assay. The degree of cytotoxicity for each sample was determined according to the reference value represented by the cells with a control (culture without sample). Statistical significance was determined by a three-way analysis of variance followed by the Mann-Whitney U-test.
  
  
  RESULTS
  No significant three-factor interaction occurred amongst LCUs, DBAs and time factors (P = 0.955). LCUs and DBAs had a significant two-factor interaction (P < 0.001). In general, the test materials cured with the light-emitting diode LCU demonstrated higher cell survival rates when compared with the those cured with the quartz tungsten halogen.
  
  
  CONCLUSIONS
  Differential toxic effects of the DBAs cured with the quartz tungsten halogen or the light-emitting diode on the fibroblast cells may prove to be very important when suitable DBAs or LCUs are used for operative restorations.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Gazi University Ankara, Turkey. gulfem@gazi.edu.tr
authors.forename: G
authors.initials: G
authors.lastname: Ergün
authors.forename: F
authors.initials: F
authors.lastname: Eğilmez
authors.forename: M B
authors.initials: MB
authors.lastname: Uçtaşli
authors.forename: S
authors.initials: S
authors.lastname: Yilmaz
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003748:Dental Equipment; D017220:Dentin-Bonding Agents / Q000528:radiation effects / Q000633:toxicity*; D005347:Fibroblasts / Q000187:drug effects*; D006219:Halogens; D007739:L Cells; D008027:Light / Q000009:adverse effects*; D051379:Mice; D044367:Phase Transition; D019279:Resin Cements / Q000528:radiation effects / Q000633:toxicity*; D012666:Semiconductors; D018709:Statistics, Nonparametric
chemical_list: D017220:Dentin-Bonding Agents; D006219:Halogens; D019279:Resin Cements