title: Cytotoxicity of dental casting alloys after conditioning in distilled water.
abstract: OBJECTIVE
  This study investigated the cytotoxicity of various types of dental casting alloys after they had been conditioned in distilled water.
  
  
  METHODS
  The casting alloys investigated included one high-noble alloy (Bioherador N) and six base-metal alloys, including four Ni-Cr alloys (Remanium CS, Heranium NA, Wiron 99, CB Soft), one Co-Cr alloy (Wirobond C), and one Cu-based alloy (Thermobond). Ten disks from each alloy were conditioned in distilled water at 37 degrees C for either 72 or 168 hours. The cytotoxicity of the alloys was then tested on Balb/C 3T3 fibroblasts, which were exposed to the alloys for 3 days at 37 degrees C. Cell viability was determined by the MTT method. The data were analyzed by ANOVA, and follow-up comparison between the groups was carried out using Tukey and t tests.
  
  
  RESULTS
  ANOVA revealed a significant effect of alloy type and conditioning time (P < .001). Bioherador N was significantly less toxic than all the other alloys in the 72-hour conditioned group. After 168 hours of conditioning, its cytotoxicity was not different (P > .05) from that of Remanium CS, Wiron 99, and Wirobond C. Thermobond and CB Soft were significantly more toxic than the other alloys at both conditioning times.
  
  
  CONCLUSIONS
  Conditioning of base-metal alloys, other than those containing Cu, for 168 hours in distilled water makes their cytotoxicity levels comparable to that of the high-noble alloy.
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan. hiyasat@just.edu.jo
authors.forename: Ahmad S
authors.initials: AS
authors.lastname: Al-Hiyasat
authors.forename: Homa
authors.initials: H
authors.lastname: Darmani
authors.forename: Omar M
authors.initials: OM
authors.lastname: Bashabsheh
mesh_terms: D000535:Aluminum / Q000633:toxicity; D000704:Analysis of Variance; D000818:Animals; D041702:BALB 3T3 Cells / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002858:Chromium Alloys / Q000633:toxicity; D004396:Coloring Agents; D003300:Copper / Q000633:toxicity; D003722:Dental Alloys / Q000633:toxicity*; D003734:Dental Casting Investment / Q000633:toxicity*; D006047:Gold Alloys / Q000633:toxicity; D016555:Matched-Pair Analysis; D008422:Materials Testing; D051379:Mice; D009532:Nickel / Q000633:toxicity; D010984:Platinum / Q000633:toxicity; D013696:Temperature; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D002858:Chromium Alloys; D004396:Coloring Agents; D003722:Dental Alloys; D003734:Dental Casting Investment; D006047:Gold Alloys; D013778:Tetrazolium Salts; D013844:Thiazoles; D014867:Water; D010984:Platinum; D003300:Copper; D009532:Nickel; D000535:Aluminum; C022616:thiazolyl blue