title: Radiopacity and cytotoxicity of Portland cement associated with niobium oxide micro and nanoparticles.
abstract: OBJECTIVE
  Mineral Trioxide Aggregate (MTA) is composed of Portland Cement (PC) and bismuth oxide (BO). Replacing BO for niobium oxide (NbO) microparticles (Nbµ) or nanoparticles (Nbη) may improve radiopacity and bioactivity. The aim of this study was to evaluate the radiopacity and cytotoxicity of the materials: (1) PC; (2) White MTA; (3) PC+30% Nbµ; (4) PC+30% Nbη.
  
  
  METHODS
  For the radiopacity test, specimens of the different materials were radiographed along an aluminum step-wedge. For cell culture assays, Saos-2 osteoblastic-cells (ATCC HTB-85) were used. Cell viability was evaluated through MTT assay, and bioactivity was assessed by alkaline phosphatase activity assay.
  
  
  RESULTS
  The results demonstrated higher radiopacity for MTA, followed by Nbµ and Nbη, which had similar values. Cell culture analysis showed that PC and PC+NbO associations promoted greater cell viability than MTA.
  
  
  CONCLUSIONS
  It was concluded that the combination of PC+NbO is a potential alternative for composition of MTA.
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, Univ. Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Leticia Boldrin
authors.initials: LB
authors.lastname: Mestieri
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, Univ. Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Mário
authors.initials: M
authors.lastname: Tanomaru-Filho
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, Univ. Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Ana Livia
authors.initials: AL
authors.lastname: Gomes-Cornélio
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, Univ. Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Loise Pedrosa
authors.initials: LP
authors.lastname: Salles
authors.affiliation: Institute of Physics, University of São Paulo, São Carlos, SP, Brazil.
authors.forename: Maria Inês Basso
authors.initials: MI
authors.lastname: Bernardi
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, Univ. Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Juliane Maria
authors.initials: JM
authors.lastname: Guerreiro-Tanomaru
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry / Q000633:toxicity*; D000704:Analysis of Variance; D001672:Biocompatible Materials / Q000737:chemistry / Q000633:toxicity; D017610:Calcium Compounds / Q000737:chemistry / Q000633:toxicity*; D002470:Cell Survival; D002478:Cells, Cultured; D003738:Dental Cements / Q000737:chemistry / Q000633:toxicity*; D004338:Drug Combinations; D005562:Formazans; D006801:Humans; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D009556:Niobium / Q000737:chemistry / Q000633:toxicity*; D010006:Osteoblasts / Q000187:drug effects; D010087:Oxides / Q000737:chemistry / Q000633:toxicity*; D017640:Silicates / Q000737:chemistry / Q000633:toxicity*; D018709:Statistics, Nonparametric; D013778:Tetrazolium Salts; D013997:Time Factors
chemical_list: D017607:Aluminum Compounds; D001672:Biocompatible Materials; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D005562:Formazans; D010087:Oxides; D017640:Silicates; D013778:Tetrazolium Salts; C086631:mineral trioxide aggregate; D009556:Niobium; C079782:MTT formazan