title: Hypoxia inhibits mineralization ability of human dental pulp cells treated with TEGDMA but increases cell survival in accordance with the culture time.
abstract: OBJECTIVE
  To evaluate the cytotoxicity and mineralization effects of TEGDMA in human dental pulp cells (hDPCs) under hypoxic and normoxic culture conditions.
  
  
  METHODS
  Cell viability was evaluated using XTT assay after incubation periods of 24, 48, or 72h. The expression of mineralization-related genes (osteonectin, osteopontin, dentin sialophosphoprotein, collagen type 1) and heme oxygenase 1 (HO-1) was assessed by quantitative real-time polymerase chain reaction at 24 and 72h.
  
  
  RESULTS
  In XTT assay, viability was higher in 0.3, 1, 2, 4, and 5mM groups in the presence of 21% O2after 24h (p<0.05). Additionally, while 0.3, 1, 2mM groups had higher cell viability in the presence of 21% O2after 48h (p<0.05), in 3mM groups cell viability was higher under 3% O2than 21% O2after both 24 and 48h (p<0.05). 1-3mM groups had higher cell viability under 3% O2after 72h (p<0.05). There was no difference between 4 and 5mM groups with regards to cell viability after 48 or 72h (p>0.05). In the gene expression study, TEGDMA-treated hDPCs showed lower mineralization potential in the presence of 3% than with 21% O2(p<0.05). hDPCs revealed higher HO 1 expression in 0.3 and 1mM groups under hypoxic than under normoxic conditions after a 72-h time period (p<0.001).
  
  
  CONCLUSIONS
  Hypoxic conditions increased cell survival in accordance with the culture period but inhibited the odontoblastic differentiation of hDPCs treated with TEGDMA.
authors.affiliation: Department of Restorative Dentistry and Endodontics, Gulhane Military Medical Academy, 06018, Ankara, Turkey. Electronic address: ztorun77@yahoo.com.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Öncel Torun
authors.affiliation: Department of Medical Genetics, Gulhane Military Medical Academy, 06018, Ankara, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Torun
authors.affiliation: Department of Restorative Dentistry and Endodontics, Gulhane Military Medical Academy, 06018, Ankara, Turkey.
authors.forename: Kadriye
authors.initials: K
authors.lastname: Demirkaya
authors.affiliation: Department of Pediatric Allergy, Gulhane Military Medical Academy, 06018, Ankara, Turkey.
authors.forename: Süleyman Tolga
authors.initials: ST
authors.lastname: Yavuz
authors.affiliation: Department of Medical and Cancer Research Center, Gulhane Military Medical Academy, 06018, Ankara, Turkey.
authors.forename: Meral
authors.initials: M
authors.lastname: Sarper
authors.affiliation: Department of Medical and Cancer Research Center, Gulhane Military Medical Academy, 06018, Ankara, Turkey; Department of Haematology, Gulhane Military Medical Academy, 06018, Ankara, Turkey.
authors.forename: Ferit
authors.initials: F
authors.lastname: Avcu
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology*; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008963:Molar; D018384:Oxidative Stress; D011092:Polyethylene Glycols / Q000494:pharmacology*; D011109:Polymethacrylic Acids / Q000494:pharmacology*; D060888:Real-Time Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D015415:Biomarkers; D011109:Polymethacrylic Acids; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols
keywords: Cytotoxicity; Hypoxia; Mineralization; Normoxia; TEGDMA