title: Nanostructured hydroxyapatite as filler for methacrylate-based root canal sealers.
abstract: OBJECTIVE
  To evaluate the effect of different concentrations of nanostructured hydroxyapatite on the radiopacity, flow and film thickness of an experimental root canal sealer.
  
  
  METHODS
  An experimental dual-cured root canal sealer was produced with a methacrylate-based co-monomer blend. Nanostructured hydroxyapatite/calcium tungstate solutions (ratios 10:90, 20:80, 30:70 and 40:60) were added to produce the sealer. Radiopacity was evaluated using a digital system and an aluminium step wedge (n=5). Flow and thickness tests were conducted in accordance with ISO 6876 (n=3). The data were analysed using one-way anova and Tukey's test (α=0.05).
  
  
  RESULTS
  All groups had levels of radiopacity in accordance with ISO 6876. The flow of the experimental sealers was not significantly different (P=0.204). All groups had a film thickness in accordance with ISO 6876 and with no statistical difference (P = 0.654).
  
  
  CONCLUSIONS
  The addition of up to 40% HA(nano) to root canal sealers did not alter their radiopacity and film thickness.
authors: Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, 2492 Rio Branco, Porto Alegre, RS, Brazil. fabricio.collares@ufrgs.br
authors: F M
authors: FM
authors: Collares
authors: V C B
authors: VC
authors: Leitune
authors: F V
authors: FV
authors: Rostirolla
authors: R M
authors: RM
authors: Trommer
authors: C P
authors: CP
authors: Bergmann
authors: S M W
authors: SM
authors: Samuel
mesh_terms: D001585:Benzoyl Peroxide / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry; D002164:Camphor / Q000031:analogs & derivatives / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D013010:Sonication; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014052:Toluidines / Q000737:chemistry; D017973:Tungsten Compounds / Q000737:chemistry; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D017610:Calcium Compounds; D003287:Contrast Media; D008689:Methacrylates; D011140:Polyurethanes; D019279:Resin Cements; D012387:Root Canal Filling Materials; D012821:Silanes; D014052:Toluidines; D017973:Tungsten Compounds; C029824:urethane dimethacrylate luting resin; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane; C017492:methacryloxypropyltrimethoxysilane; D002164:Camphor; C018858:calcium tungstate; D017886:Durapatite; C038496:N,N-bis(2-hydroxyethyl)-4-toluidine; C553149:camphorquinone; D001585:Benzoyl Peroxide