title: Apical Sealing Ability of Mineral Trioxide Aggregate, Intermediate Restorative Material and Calcium Enriched Mixture Cement: A Bacterial Leakage Study.
abstract: BACKGROUND
  Thisin vitrostudy compared the apical sealing ability of three common root end filling materials namely mineral trioxide aggregate (MTA), intermediate restorative material (IRM) and calcium-enriched mixture (CEM) cement using a bacterial leakage model.
  
  
  METHODS
  The study was conducted on 83 single-rooted human teeth. Tooth crowns were cut and root canals were prepared using the step-back technique. Apical 3 mm of the roots were cut and a three-mm-deep cavity was prepared using an ultrasonic instrument. The samples were divided into three groups (n=25) according to the root-end filling material including MTA, IRM and CEM cement. The roots were inserted into cut-end microtubes. After sterilization with ethylene oxide, microtubes were placed in sterile vials containing 10 mL of Brain Heart Infusion (BHI) broth and incubated at 37°C and 0.1 mL ofEnterococcus faecalissuspension compatible with 0.5 McFarland standard (1.5×108cell/ ml), which was refreshed daily. This procedure was continued for 70 days. The data were analyzed using the chi-square, Kruskal-Wallis and log rank tests. The level of significance was set at 0.05.
  
  
  RESULTS
  No significant difference was found in bacterial microleakage among three groups; MTA showed slightly (but not significantly) less microleakage than IRM and CEM. However, the difference in the mean time of microleakage was significant among the groups (P<0.04) and in MTA samples leakage occurred in a longer time than CEM (P<0.012).
  
  
  CONCLUSIONS
  The three tested root end filling materials had equal sealing efficacy for preventing bacterial leakage.
authors: Department of Endodontics, Dental School, Hamedan University of Medical Science, Hamadan, Iran.
authors: Shahriar
authors: S
authors: Shahriari
authors: Department of Endodontics, Dental School, Hamedan University of Medical Science, Hamadan, Iran.
authors: Farhad
authors: F
authors: Faramarzi
authors: Department of Microbiology, Medical School, Hamadan University of Medical Sciences, Hamadan, Iran.
authors: Mohammad-Yousef
authors: MY
authors: Alikhani
authors: Modeling of Noncommunicable Diseases Research Center, Department of Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
authors: Maryam
authors: M
authors: Farhadian
authors: Department of Endodontics, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran.
authors: Seyedeh Sareh
authors: SS
authors: Hendi
keywords: Apical Seal; Bacterial Leakage; Microleakage; Root-End Filling; Seal