title: Effect of the TiO2 nanoparticles on the selected physical properties of mineral trioxide aggregate.
abstract: BACKGROUND
  Some of the efforts to improve the properties of Mineral Trioxide Aggregate (MTA) include incorporation of some nanoparticles such as Titanium dioxide (TiO2). The aim of this study was to evaluate the effect of TiO2 nanoparticles on the setting time, working time, push-out bond strength and compressive strength of MTA.
  
  
  METHODS
  The physical properties to be evaluated were determined using the ISO 6786:2001 and 9917 specifications. Fifteen samples of each material (MTA or MTA with 1% weight ratio of TiO2 Nanoparticles) were prepared for any evaluated physical property. Data were analyzed using descriptive statistics and T-test. Statistical significance was set atP<0.05.
  
  
  RESULTS
  There was the significant effect of the material type (presence and absence of TiO2 nanoparticles) on the push-out bond strength, compressive strength, working time and setting time, with significantly higher values achieved in the group with TiO2 nanoparticles than the group without these particles (P=0.01 for the setting time and compressive strength,P=0.03 for the working time andP=0.001 for the bond strength).
  
  
  CONCLUSIONS
  Based on the findings of thisin vitrostudy, incorporation of the TiO2 nanoparticles with weight ratio of 1% increased the setting time, working time, compressive strength and push out bond strength of MTA.Key words:Mineral trioxide aggregate, nanoparticles, physical properties, titanium dioxide.
authors.affiliation: Associate Professor, Department of Endodontics, Dental Faculty, Tabriz University (Medical Sciences), Tabriz, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Samiei
authors.affiliation: Assistant Professor, Department of Endodontics, Dental and Periodontal Research Center, Dental Faculty, Tabriz University (Medical Sciences), Tabriz, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Janani
authors.affiliation: Professor, Department of Pediatric Dentistry, Dental Faculty, Tabriz University (Medical Sciences), Tabriz, Iran.
authors.forename: Naser
authors.initials: N
authors.lastname: Asl-Aminabadi
authors.affiliation: Assistant Professor, Department of Endodontics, Dental Faculty, Tabriz University (Medical Sciences), Tabriz, Iran.
authors.forename: Negin
authors.initials: N
authors.lastname: Ghasemi
authors.affiliation: Assistant Professor, Department of Chemistry, Tabriz University , Tabriz, Iran.
authors.forename: Baharak
authors.initials: B
authors.lastname: Divband
authors.affiliation: Research Assistant, Dental Faculty, Tabriz University (Medical Sciences), Tabriz, Iran.
authors.forename: Sajjad
authors.initials: S
authors.lastname: Shirazi
authors.affiliation: Private Practice, Tabriz, Iran.
authors.forename: Kayvan
authors.initials: K
authors.lastname: Kafili