title: In vitro cytotoxicity evaluation of elemental ions released from different prosthodontic materials.
abstract: OBJECTIVE
  This study investigated the cytotoxicity of elemental ions contained in four fixed prosthodontic materials (gold, nickel-chromium, stainless-steel alloys and CAD-CAM ceramics).
  
  
  METHODS
  According to the determination of elements released from prosthodontic materials by using inductively coupled plasma mass spectroscopy, similar amounts of elements Pd, Ag, Zn, Cu, Ni, Cr, Mo, Be, Fe, Al, and K were prepared as salt solutions. Wells with a tenfold higher concentration of the tested elements were used as positive controls, while a well without any tested element was used as a negative control. These salt solutions were tested for cytotoxicity by culturing mouse L-929 fibroblasts in the salt solutions for a 7-day period of incubation. Then, the percentage of viable cells for each element was measured using trypan blue exclusion assay. The data (n=5) were statistically analyzed by ANOVA/Tukey test (p<0.05).
  
  
  RESULTS
  The results showed a statistically significant difference for the cytotoxic effect of the tested elements salt solutions. For the released element concentrations the lowest percentage of viable cells (mean+/-SD) was evident with Zn, Cu or Ni indicating that they are the highly toxic elements. Be and Ag were found to be intermediate in cytotoxic effect. Fe, Cr, Mo, Al, Pd or K were found to be the least cytotoxic elements.
  
  
  CONCLUSIONS
  Zn and Cu released from gold alloys, and Ni released from nickel-chromium alloys, which are commonly used as fixed prosthodontic restorations, show evidence of a high cytotoxic effect on fibroblast cell cultures.
authors.affiliation: Department of Biomaterials Science, Baylor College of Dentistry, Texas A&M Health Science Center, 3302 Gaston Ave., Dallas, TX, 75246, United States. welshahawy@bcd.tamhsc.edu
authors.forename: Waleed M
authors.initials: WM
authors.lastname: Elshahawy
authors.forename: Ikuya
authors.initials: I
authors.lastname: Watanabe
authors.forename: Phillip
authors.initials: P
authors.lastname: Kramer
mesh_terms: D000535:Aluminum / Q000633:toxicity; D000818:Animals; D001608:Beryllium / Q000633:toxicity; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002857:Chromium / Q000633:toxicity; D002858:Chromium Alloys / Q000633:toxicity; D004396:Coloring Agents; D017076:Computer-Aided Design; D003300:Copper / Q000633:toxicity; D003722:Dental Alloys / Q000633:toxicity*; D003776:Dental Porcelain / Q000633:toxicity*; D005347:Fibroblasts / Q000187:drug effects*; D006046:Gold / Q000633:toxicity; D006047:Gold Alloys / Q000633:toxicity; D007501:Iron / Q000633:toxicity; D013058:Mass Spectrometry; D008422:Materials Testing; D051379:Mice; D008982:Molybdenum / Q000633:toxicity; D009532:Nickel / Q000633:toxicity; D010165:Palladium / Q000633:toxicity; D011188:Potassium / Q000633:toxicity; D013193:Stainless Steel / Q000633:toxicity; D014343:Trypan Blue; D015032:Zinc / Q000633:toxicity
chemical_list: D002858:Chromium Alloys; D004396:Coloring Agents; D003722:Dental Alloys; D006047:Gold Alloys; D002857:Chromium; D003776:Dental Porcelain; D013193:Stainless Steel; D010165:Palladium; D006046:Gold; D003300:Copper; D009532:Nickel; D008982:Molybdenum; D000535:Aluminum; D007501:Iron; D014343:Trypan Blue; D015032:Zinc; D001608:Beryllium; D011188:Potassium