title: [Cytotoxicity of several materials of full crowns on human gingival fibroblast cells in vitro].
abstract: OBJECTIVE
  To evaluate the cytotoxicity of Ni-Cr base metal alloy, gold casting alloy and castable dental ceramic on human gingival fibroblast cells (HGFC)ain vitro.
  
  
  METHODS
  HGFC were cultured with extractions of Ni-Cr base metal alloy, gold casting alloy and castable dental ceramic. Relative growth rate (RGR) was analyzed with a methyl thiazolyl tetrazolium (MTT) assay. The shape of HGFCs was observed when HGFCs were directly contacted with three prosthodontic materials. Factor analysis was performed using Stata 9.1 software.
  
  
  RESULTS
  The relative growth rates of HGFCs cultured with gold casting alloy were 1.016,1.014,0.824 and 0.796,respectively. The relative growth rates of HGFCs cultured with Ni-Cr base metal alloy were 1.028,1.079,0.903 and 0.809,respectively. The relative growth rates of HGFCs cultured with castable dental ceramic were 1.018,1.030,0.924 and 0.818, respectively. There was significant difference of RGR between the gold casting alloy and the Ni-Cr base metal alloy groups(P=0.021). No significant difference of RGR was observed between the gold casting alloy and castable dental ceramic groups (P>0.05).No significant difference of RGR was observed between the Ni-Cr base metal alloy and castable dental ceramic groups (P>0.05). Cytotoxical grades of Ni-Cr base metal alloy, gold casting alloy and castable dental ceramic were 0 to 1. HGFC could grow around the three prosthodontic materials.
  
  
  CONCLUSIONS
  Ni-Cr base metal alloy has more cytotoxic effect in direct contact test than in extraction test on HGFC. Gold casting alloy and castable dental ceramic have good biocompatibility. Supported by Medical PI Project for Provincial Advancement through Science and Education of Jiangsu Province (RC2007099).
authors.affiliation: Institute of Stomatology, Nanjing Medical University, Nanjing 210029, Jiangsu Province, China. mahong615@163.com
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Fei-Min
authors.initials: FM
authors.lastname: Zhang
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
mesh_terms: D002858:Chromium Alloys; D003442:Crowns; D003722:Dental Alloys / Q000633:toxicity*; D005347:Fibroblasts; D005881:Gingiva / Q000166:cytology; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys