title: The direct cytotoxic effects of medicaments used in endodontic regeneration on human dental pulp cells.
abstract: OBJECTIVE
  The purpose of this in vitro study was to evaluate the effects of intracanal medicaments commonly used in endodontic regeneration on the survival of human dental pulp cells (DPCs).
  
  
  METHODS
  DPCs were cultured and exposed to either no medicament treatment or low concentrations (0.3-5 mg ml(-1) ) of calcium hydroxide [Ca(OH)2 ], triple antibiotic paste (TAP), or double antibiotic paste (DAP) for 3 days. After that, toxicity to the DPCs was determined by lactate dehydrogenase activity assays (LDH) and cell proliferation was measured by colorimetric assays (WST-1). Two-way anova followed by Fisher's protected least significant differences was used for statistical analyses (α = 0.05).
  
  
  RESULTS
  The group-by-concentration interactions were significant for the LDH and WST-1 assays (P < 0.0001). For the LDH assays, only the highest tested concentration (5 mg ml(-1) ) of Ca(OH)2 and TAP caused significant toxicity to the DPCs compared with the untreated control, while four tested concentrations of DAP (0.5, 1, 2.5, and 5 mg ml(-1) ) caused significant toxicity to the DPCs compared with the untreated control. For the WST-1 assays, the highest concentrations that did not negatively affect the proliferation rate of DAP, TAP and Ca(OH)2 were 0.3, 2, and 2.5 mg ml(-1) , respectively.
  
  
  CONCLUSIONS
  The low concentrations of intracanal medicaments tested in this study were not cytotoxic in cultured cells. However, these concentrations are much lower than the concentrations that have been advocated in endodontic regeneration. Furthermore, the negative effects of TAP on DPCs were detected at lower concentrations by using the WST-1 assays than by measuring the LDH release.
authors.affiliation: Department of Prosthetic Dental Science, King Saud University, Riyadh, Saudi Arabia; Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, IN, USA.
authors.forename: Nawaf
authors.initials: N
authors.lastname: Labban
authors.forename: Ghaeth H
authors.initials: GH
authors.lastname: Yassen
authors.forename: L Jack
authors.initials: LJ
authors.lastname: Windsor
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Platt
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000633:toxicity; D002126:Calcium Hydroxide / Q000008:administration & dosage / Q000633:toxicity; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000633:toxicity; D003124:Colorimetry / Q000379:methods; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D007202:Indicators and Reagents; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008422:Materials Testing; D008795:Metronidazole / Q000008:administration & dosage / Q000633:toxicity; D008911:Minocycline / Q000008:administration & dosage / Q000633:toxicity; D012038:Regeneration; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000633:toxicity*; D013778:Tetrazolium Salts; D013997:Time Factors
chemical_list: C110656:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium; D000900:Anti-Bacterial Agents; D007202:Indicators and Reagents; D012388:Root Canal Irrigants; D013778:Tetrazolium Salts; D008795:Metronidazole; D002939:Ciprofloxacin; D007770:L-Lactate Dehydrogenase; D008911:Minocycline; D002126:Calcium Hydroxide
keywords: calcium hydroxide; cytotoxicity; double antibiotic paste; endodontic regeneration; triple antibiotic paste