title: [Culture of human cells from the apical papilla in vitro and effect of TNF-α on these cells].
abstract: OBJECTIVE
  The aim of this study was to culture human cells from the apical papilla in vitro, study the biological effect of TNF-α on these cells, explore the possibility of their dentinogenesis under inflammation, and compare the dental pulp cells with them.
  
  
  METHODS
  The apical papilla, as well as the pulp tissues from the third permanent molar of a 15-year-old girl were digested in Hanks solution including collagenase and dispase and cultured. The fourth passage cells were challenged with different concentration of TNF-α and detected for the proliferation activity by MTT. One-Way ANOVA was conducted using SPSS11.0 software package.
  
  
  RESULTS
  The apical papilla cells presented elongated shape, polygon or spindle shape, respectively. They exhibited fibroblastic characteristics. The apical papilla cells had stronger proliferation activity than the dental pulp cells. At the concentration of 10 ng/mL and 50 ng/mL, TNF-α significantly enhanced the proliferating activity of the two kinds of the cells(P<0.05).
  
  
  CONCLUSIONS
  Stronger proliferation activity of the apical papilla cells, especially under inflammation, would possibly be benefit to continuing development of the root of young permanent tooth with dental pulp necrosis and apical periodontitis after appropriate treatment.
authors.affiliation: Department of Endodontics, School of Stomatology, Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan 250012, Shandong Province, China.
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Pi-shan
authors.initials: PS
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D003771:Dental Papilla; D003782:Dental Pulp; D003790:Dental Pulp Necrosis; D005260:Female; D005347:Fibroblasts; D006801:Humans; D066298:In Vitro Techniques; D014409:Tumor Necrosis Factor-alpha
chemical_list: D014409:Tumor Necrosis Factor-alpha