title: Influence of different light curing units on the cytotoxicity of various dental composites.
abstract: OBJECTIVE
  To evaluate the dependence of the toxicity of various dental composites on the use of high- and low-power light curing units (LCUs).
  
  
  METHODS
  The composites Filtek Z 250, Durafill VS, Solitaire 2 and Grandio were polymerized using different light densities from three LCUs, namely Heliolux II, Swiss Master Light (SML) and a prototype LED. The toxicity of polymerized samples was tested by exposing them to the cell culture medium up to 28 days. The extracts of the composites were collected daily and used for incubation in human gingival fibroblasts cultures.
  
  
  RESULTS
  Slow, low-intensity curing using the LED or the Heliolux II showed similar characteristics for all four composites, regarding the cell viability rate of human gingival fibroblasts. After 1 day of storage suboptimal results could be observed for the SML/Durafill and optimal results for SML/Grandio combination (approximately 100% cell viability). In addition, the composite Solitaire the SML yielded significantly better results than the other LCUs (cell viability, p < or = 0.001: SML 60.5%, Heliolux 44.5%, LED 44.2%). Furthermore, the combination of the SML with Z 250 composite showed, after the first day and up to day 28, statistically significantly higher cell viability rates than the combination with the LED or Heliolux II.
  
  
  CONCLUSIONS
  This study shows that the combination of a high power LCU with some composites positively influences the HGF cell viability effected by the investigated composite extracts. Moreover, there is further indication that a reduction of composite toxicity is possible if the curing mode is adapted to the used composite.
authors.affiliation: Department of Conservative Dentistry, Friedrich-Schiller-University Jena, An der Alten Post 4, Jena D-07743, Germany. bernd.w.sigusch@med.uni-jena.de
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Sigusch
authors.forename: Andrea
authors.initials: A
authors.lastname: Völpel
authors.forename: Ingo
authors.initials: I
authors.lastname: Braun
authors.forename: Alexander
authors.initials: A
authors.lastname: Uhl
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Jandt
mesh_terms: D000328:Adult; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity*; D003748:Dental Equipment; D005260:Female; D005347:Fibroblasts / Q000187:drug effects; D005881:Gingiva / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D008027:Light; D044367:Phase Transition
chemical_list: D003188:Composite Resins