title: Niobium pentoxide as radiopacifying agent of calcium silicate-based material: evaluation of physicochemical and biological properties.
abstract: OBJECTIVE
  The physicochemical properties and the tissue reaction promoted by microparticulated or nanoparticulated niobium pentoxide (Nb2O5) added to calcium silicate-based cement (CS), compared to MTA-Angelus™, were evaluated.
  
  
  METHODS
  Materials were submitted to the tests of radiopacity, setting time, pH, and calcium ion release. Polyethylene tubes filled with the materials were implanted into rats subcutaneously. After 7, 15, 30, and 60 days, the specimens were fixed and embedded in paraffin. Hematoxylin & eosin (H&E)-stained sections were used to compute the number of inflammatory cells (IC). Interleukin-6 (IL-6) detection was performed, and the number of immunolabeled cells was obtained; von Kossa method was also carried out. Data were subjected to ANOVA and Tukey test (p ≤ 0.05).
  
  
  RESULTS
  Nb2O5micro and Nb2O5nano provided to the CS radiopacity values (3.52 and 3.75 mm Al, respectively) superior to the minimum recommended. Groups containing Nb2O5 presented initial setting time significantly superior than mineral trioxide aggregate (MTA). All materials presented an alkaline pH and released calcium ions. The number of IC and IL-6 immunolabeled cells in the CS + Nb2O5 groups was significantly reduced in comparison to MTA in all periods. von Kossa-positive structures were observed adjacent to implanted materials in all periods.
  
  
  CONCLUSIONS
  The addition of Nb2O5 to the CS resulted in a material biocompatible and with adequate characteristics regarding radiopacity and final setting time and provides an alkaline pH to the environment. Furthermore, the particle size did not significantly affect the physicochemical and biological properties of the calcium silicate-based cement.
  
  
  CONCLUSIONS
  Niobium pentoxide can be used as radiopacifier for the development of calcium silicate-based materials.
authors: Department of Restorative Dentistry, UNESP-Univ. Estadual Paulista, Dental School, Araraquara, SP, Brazil.
authors: Guilherme F
authors: GF
authors: Silva
authors: Department of Restorative Dentistry, UNESP-Univ. Estadual Paulista, Dental School, Araraquara, SP, Brazil.
authors: Mário
authors: M
authors: Tanomaru-Filho
authors: Physics Institute of São Carlos, Grupo Crescimento de Cristais e Materiais Cerâmicos, University of São Paulo-USP, São Carlos, SP, Brazil.
authors: Maria I B
authors: MI
authors: Bernardi
authors: Department of Restorative Dentistry, UNESP-Univ. Estadual Paulista, Dental School, Araraquara, SP, Brazil.
authors: Juliane M
authors: JM
authors: Guerreiro-Tanomaru
authors: Laboratory of Histology and Embryology, UNESP-Univ. Estadual Paulista, Dental School, Araraquara, SP, Brazil. pcerri@foar.unesp.br.|Department of Morphology-Laboratory of Histology and Embryology, UNESP-Univ Estadual Paulista, Dental School, Rua Humaitá, 1680, Centro, CEP, 14801-903, Araraquara, SP, Brazil. pcerri@foar.unesp.br.
authors: Paulo S
authors: PS
authors: Cerri
mesh_terms: D000818:Animals; D017610:Calcium Compounds / Q000737:chemistry / Q000494:pharmacology; D003287:Contrast Media / Q000737:chemistry / Q000494:pharmacology; D003738:Dental Cements / Q000737:chemistry / Q000494:pharmacology; D008422:Materials Testing; D009556:Niobium / Q000737:chemistry / Q000494:pharmacology; D010087:Oxides / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D017640:Silicates / Q000737:chemistry / Q000494:pharmacology
chemical_list: D017610:Calcium Compounds; D003287:Contrast Media; D003738:Dental Cements; D010087:Oxides; D017640:Silicates; D009556:Niobium; C073337:niobium pentoxide; C031293:calcium silicate
keywords: Biocompatibility; Calcium silicate cement; Mineral trioxide aggregate; Physicochemical properties; Radiopacifiers
references: J Biomed Mater Res B Appl Biomater. 2012 Oct;100(7):1773-81
references: 22821748
references: Int Endod J. 2014 May;47(5):437-48
references: 24033490
references: J Biomed Mater Res A. 2014 Dec;102(12):4336-45
references: 24497271
references: Dent Mater. 2010 Oct;26(10 ):974-92
references: 20655582
references: J Endod. 2007 Mar;33(3):295-8
references: 17320718
references: Int Endod J. 2013 Mar;46(3):205-10
references: 22882173
references: J Endod. 2006 Mar;32(3):193-7
references: 16500224
references: J Endod. 2010 May;36(5):899-903
references: 20416442
references: J Endod. 2008 Jun;34(6):715-7
references: 18498897
references: J Endod. 2012 Mar;38(3):394-7
references: 22341082
references: J Endod. 2007 Feb;33(2):163-6
references: 17258637
references: J Appl Oral Sci. 2008 Nov-Dec;16(6):376-9
references: 19082394
references: J Endod. 2010 Mar;36(3):400-13
references: 20171353
references: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008 Jan;105(1):e54-7
references: 18155604
references: Arch Oral Biol. 1991;36(2):117-28
references: 2059161
references: Biomaterials. 2002 Oct;23(19):4001-10
references: 12162333
references: J Appl Biomater Funct Mater. 2015 Jan-Mar;13(1):43-60
references: 25199071
references: Int Endod J. 2007 Jun;40(6):462-70
references: 17459120
references: Calcif Tissue Int. 2003 May;72(5):537-47
references: 12724828
references: Clin Oral Investig. 2014 Jul;18(6):1597-604
references: 24233183
references: Int Endod J. 2010 Jan;43(1):21-30
references: 19891720
references: Dent Mater. 2011 Sep;27(9):879-91
references: 21571361
references: J Biomed Mater Res B Appl Biomater. 2013 Oct;101(7):1107-23
references: 23559495
references: J Biomed Mater Res B Appl Biomater. 2005 Oct;75(1):18-24
references: 16025471
references: J Endod. 2009 Feb;35(2):256-60
references: 19166785
references: Oral Dis. 2012 Apr;18(3):236-43
references: 22050374
references: J Endod. 2013 Jul;39(7):915-8
references: 23791263
references: J Dent. 2013 Feb;41(2):106-13
references: 22564371
references: Biomaterials. 1999 Jan;20(2):167-73
references: 10022786
references: Int Endod J. 2011 Feb;44(2):100-10
references: 21039627