title: Zinc oxide nano-particles as sealer in endodontics and its sealing ability.
abstract: OBJECTIVE
  The aim of this study was to evaluate the sealing ability of new experimental nano-ZOE-based sealer.
  
  
  METHODS
  Three types of nano-ZOE-based sealer (calcined at different temperatures of 500, 600 and 700°C) with two other commercially available sealers (AH26 and micro-sized zinc oxide eugenol sealer) were used.
  
  
  METHODS
  Zinc oxide nano-particles were synthesized by a modified sol-gel method. The structure and morphology of the prepared powders were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. The instrumented canals of 60 single-rooted teeth were divided into five groups (n = 10), with the remaining ten used as controls. The canals were filled with gutta-percha using one of the materials mentioned above as sealer. After 3, 45 and 90 days, the samples were connected to a fluid filtration system.
  
  
  METHODS
  The data were analyzed using Student's t-test.
  
  
  RESULTS
  The XRD patterns and TEM images revealed that all the synthesized powders had hexagonal wurtzite structures with an average particle size of about 30-60 nm at different calcination temperatures. Microleakage in AH26 groups was significantly more than that in three groups of ZnO nano-particles at all the three evaluation intervals. Apical microleakage of ZnO micro-powders was significantly more than that of all the materials, but the sealing ability of ZnO nano-powder sealers did not differ significantly.
  
  
  CONCLUSIONS
  The results of this study showed that the synthesized ZnO nano-powder sealers are suitable for use as a nano-sealer in root canal therapy to prevent leakage; however, further studies should be carried out to verify their safety.
authors.affiliation: Dental Material Research Center, Department of Endodontics, School of Dentistry, Mashhad University of Medical Sciences, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Javidi
authors.affiliation: Dental Material Research Center, Department of Endodontics, School of Dentistry, Mashhad University of Medical Sciences, Iran.
authors.forename: Mina
authors.initials: M
authors.lastname: Zarei
authors.affiliation: Dental Research Center, Department of Endodontics, School of Dentistry, Mashhad University of Medical Sciences (MUMS), Iran.
authors.forename: Neda
authors.initials: N
authors.lastname: Naghavi
authors.affiliation: Endodontist, Private Practice, Iran.
authors.forename: Majed
authors.initials: M
authors.lastname: Mortazavi
authors.affiliation: General Practitioner, Iran.
authors.forename: Amir Hosein
authors.initials: AH
authors.lastname: Nejat
keywords: AH26; dental material; microleakage; nano-particle sealers; sealer; zinc oxide eugenol