title: Evaluation of the radiopacity and cytotoxicity of Portland cements containing bismuth oxide.
abstract: OBJECTIVE
  This study aimed at evaluating the radiopacity and cytotoxicity of Portland cements containing bismuth oxide (PcBo) in varying ratios.
  
  
  METHODS
  Specimens measuring 10 mm in diameter and 1 mm in thickness were radiographed with an aluminum step wedge using an occlusal film. The radiographs were digitized, and the radiopacity of each material was compared to the different thicknesses of the aluminum step wedge. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of each material was determined in immortalized human periodontal ligament (IPDL) cells.
  
  
  RESULTS
  The results demonstrated that Portland cement with 20% bismuth oxide presented greater radiopacity (P < .05) compared to the mixtures with less bismuth oxide. The cell viabilities of all PcBo groups were statistically similar (P > .05) throughout the experimental period.
  
  
  CONCLUSIONS
  These results indicate that Portland cement with 20% bismuth oxide has a greater potential for being used as a root-end filling material compared to Portland cement with less bismuth oxide.
authors.affiliation: Department of Oral and Maxillofacial Pathology, College of Dentistry, Wonkwang University, Iksan, Republic of Korea.
authors.forename: Eun-Cheol
authors.initials: EC
authors.lastname: Kim
authors.forename: Byung-Cheon
authors.initials: BC
authors.lastname: Lee
authors.forename: Hoon-Sang
authors.initials: HS
authors.lastname: Chang
authors.forename: Wan
authors.initials: W
authors.lastname: Lee
authors.forename: Chan-Ui
authors.initials: CU
authors.lastname: Hong
authors.forename: Kyung-San
authors.initials: KS
authors.lastname: Min
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry* / Q000633:toxicity; D001729:Bismuth / Q000737:chemistry / Q000633:toxicity*; D017610:Calcium Compounds / Q000737:chemistry* / Q000633:toxicity; D002470:Cell Survival; D003738:Dental Cements / Q000737:chemistry / Q000633:toxicity*; D004338:Drug Combinations; D052162:Human papillomavirus 16; D006801:Humans; D010087:Oxides / Q000737:chemistry* / Q000633:toxicity; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects*; D011859:Radiography; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000633:toxicity*; D017640:Silicates / Q000737:chemistry* / Q000633:toxicity; D013997:Time Factors; D019553:Tooth, Nonvital / Q000000981:diagnostic imaging*
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; C033301:bismuth oxide; D001729:Bismuth