title: Comparative evaluation of sealing ability and microstructure of MTA and Biodentine after exposure to different environments.
abstract: OBJECTIVE
  The aim of this study was to evaluate the sealing ability and morphological microstructure of Biodentine in comparison to ProRoot mineral trioxide aggregate (MTA) after storage in an acidic environment.
  
  
  METHODS
  Biodentine and ProRoot MTA were prepared and packed into the canal lumen of dentin disks. Twenty specimens of each material were further randomly divided into two groups according to the storage media: group A: materials with saline as storage medium; group B: materials with citric acid buffered at pH 5.4 as storage medium. The sealing ability was evaluated at 1, 3, 6, and 24 h and 1 or 3 months, using a fluid transport model for quantitative analysis of endodontic microleakage. The morphological microstructures of the materials were also evaluated using scanning electron microscopy.
  
  
  RESULTS
  During the first 24 h, MTA showed greater fluid transport values than Biodentine in both environments. At the 3-month measurement, when the materials were stored in saline, MTA showed greater ability to prevent fluid movement than Biodentine (p < 0.0001). However, when the materials were stored in an acidic environment, no statistical significant difference was found after 3 months. After storage in saline, both materials showed an uneven crystalline surface with similar hexagonal crystals. The microstructure of Biodentine changed after exposure to citric acid, showing a relatively smooth surface with more spheroidal crystals.
  
  
  CONCLUSIONS
  The exposure to an acidic environment, within the limits of this study, seems to result in morphological changes of Biodentine in a different manner than MTA. MTA shows good ability to prevent fluid movement over time, in both environments. The ability of Biodentine to prevent fluid movement over time was enhanced in the acidic environment.
  
  
  CONCLUSIONS
  The findings of the present study could imply that both materials are indicated for use in an acidic environment.
authors.affiliation: Department of Endodontics, School of Dentistry, National and Kapodistrian University of Athens, 2 Thivon Str., 11527, Goudi, Athens, Greece.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Agrafioti
authors.affiliation: Division of Endodontology, Department of Cariology, Endodontology and Pedodontology, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University, Amsterdam, The Netherlands.
authors.forename: Nestor
authors.initials: N
authors.lastname: Tzimpoulas
authors.affiliation: Laboratory of Mineralogy, Petrology and Economic Geology, Department of Geological Sciences, School of Mining and Metallurgical Engineering, National Technical University of Athens, Athens, Greece.
authors.forename: Elias
authors.initials: E
authors.lastname: Chatzitheodoridis
authors.affiliation: Department of Endodontics, School of Dentistry, National and Kapodistrian University of Athens, 2 Thivon Str., 11527, Goudi, Athens, Greece. ekontak@dent.uoa.gr.
authors.forename: Evangelos G
authors.initials: EG
authors.lastname: Kontakiotis
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D000818:Animals; D017610:Calcium Compounds / Q000737:chemistry*; D002417:Cattle; D003763:Dental Leakage / Q000517:prevention & control*; D003799:Dental Stress Analysis; D004338:Drug Combinations; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000737:chemistry*; D012387:Root Canal Filling Materials / Q000737:chemistry; D017640:Silicates / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; C506393:tricalcium silicate
keywords: Acidic environment; Biodentine; MTA; Microstructure; Sealing ability