title: Comparing the Coronal Seal of Different Thicknesses of MTA with Gutta-Percha after Post Space Preparation.
abstract: BACKGROUND
  The aim of this study was to compare the coronal seal of different thicknesses of MTA with gutta-percha after post space preparation.
  
  
  METHODS
  A total of 50 maxillary central incisors randomly divided into 5 experimental groups (n = 8). After preparation of the root canals with step back technique, in groups 1 and 2, post spaces were prepared and 4 or 5 mm gutta-percha remained in the apical, respectively. In groups 3, 4, and 5, there was 1-2 and 3 mm MTA in the apical, respectively. The ten teeth serve as control groups. The teeth were connected to a bacterial microleakage evaluation system. The study period was 120 days and the samples were evaluated on ten-day intervals; Meier-Kaplan technique was used for estimation of the mean time of microleakage to occur. Log-rank test was used for comparison of microleakage.
  
  
  RESULTS
  Number of samples exhibiting microleakage in MTA was less than those of gutta-percha at all intervals. Means of days with no microleakage were maximum and minimum with 3 mm MTA and 4 mm gutta-percha, respectively.
  
  
  CONCLUSIONS
  Obturation of root canals using the MTA technique provides a proper seal with the minimum thickness of MTA in teeth requiring post space preparation.
authors.affiliation: Department of Endodontics, Dental Faculty, Tabriz University (Medical Sciences), Tabriz 5154613475, Iran.
authors.forename: Mohammad Frough
authors.initials: MF
authors.lastname: Reyhani
authors.affiliation: Department of Endodontics, Dental Faculty, Tabriz University (Medical Sciences), Tabriz 5154613475, Iran.
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Yavari
authors.affiliation: Department of Endodontics, Dental Faculty, Tabriz University (Medical Sciences), Tabriz 5154613475, Iran.
authors.forename: Negin
authors.initials: N
authors.lastname: Ghasemi
authors.affiliation: Dental and Periodontal Research Center, Dental Faculty, Tabriz University (Medical Sciences), Tabriz 5154613475, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Rahimi
authors.affiliation: Department of Microbiology, Medical Faculty, Tabriz University (Medical Sciences), Tabriz 5154613475, Iran.
authors.forename: Mohammad Hosien Soroush
authors.initials: MH
authors.lastname: Barhaghi
authors.affiliation: Department of Endodontics, Dental Faculty, Tabriz University (Medical Sciences), Tabriz 5154613475, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Mokhtari
authors.affiliation: Dental Faculty, Tabriz University (Medical Sciences), Tabriz 5154613475, Iran.
authors.forename: Payman
authors.initials: P
authors.lastname: Sarikhani
mesh_terms: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D006171:Gutta-Percha; D006801:Humans; D010087:Oxides; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation / Q000379:methods; D017640:Silicates
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D006171:Gutta-Percha