title: Electron microscopic analysis of the effects of chemical retraction agents on cultured rat keratinocytes.
abstract: BACKGROUND
  Chemical retraction agents used in fixed prosthodontics for temporary displacement of free gingival tissue before impression making can cause injury to the gingival tissue cells.
  
  
  OBJECTIVE
  This study evaluated changes in cultured rat keratinocytes treated with 2 chemical agents used for gingival retraction. Treated cultures were compared with untreated cultures.
  
  
  METHODS
  Keratinocytes of rat gingiva were grown in a specific medium for 10 days. After treating 1 group of specimens with 0.05% tetrahydrozoline and another group with 25% aluminum chloride, both for 10 minutes, the cultured cells were examined with scanning and transmission electron microscopy and compared with control specimens.
  
  
  RESULTS
  Twenty-five percent aluminum chloride produced a significantly greater extent of cellular damage than 0.05% tetrahydrozoline, which caused only mild changes in the cultured cells.
  
  
  CONCLUSIONS
  On the basis of the morphologic and ultrastructural changes in primary cell cultures of rat keratinocytes observed in this study, it was concluded that 25% aluminum chloride was significantly more aggressive than 0.05% tetrahydrozoline.
authors.affiliation: Dental Department, Centre of Fixed Prosthodontics and Occlusion, Medical Faculty, University of Ljubljana, Slovenia.
authors.forename: Igor
authors.initials: I
authors.lastname: Kopac
authors.forename: Milan
authors.initials: M
authors.lastname: Sterle
authors.forename: Ljubo
authors.initials: L
authors.lastname: Marion
mesh_terms: D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000494:pharmacology; D000818:Animals; D001252:Astringents / Q000494:pharmacology*; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D002478:Cells, Cultured; D002712:Chlorides / Q000494:pharmacology; D003470:Culture Media; D005110:Extracellular Space / Q000187:drug effects; D005881:Gingiva / Q000166:cytology / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology; D007365:Intercellular Junctions / Q000187:drug effects / Q000648:ultrastructure; D015603:Keratinocytes / Q000187:drug effects* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008871:Microvilli / Q000187:drug effects / Q000648:ultrastructure; D015388:Organelles / Q000187:drug effects / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D017607:Aluminum Compounds; D001252:Astringents; D002712:Chlorides; D003470:Culture Media; D007093:Imidazoles; D000077410:Aluminum Chloride; C005810:tetrahydrozoline