title: A phosphate-buffered saline intracanal dressing improves the biomineralization ability of mineral trioxide aggregate apical plugs.
abstract: BACKGROUND
  Recently, it was shown that the biomineralization process promoted by the interaction of mineral trioxide aggregate (MTA) with dentin in phosphate-buffered saline (PBS) positively influenced the push-out bond strength of the cement. This study investigated if the use of a PBS intracanal dressing promotes the biomineralization process of MTA apical plugs using an ex vivo apexification model.
  
  
  METHODS
  White MTA was introduced into single-rooted teeth with standardized artificially created open apices to form 5-mm-thick apical plugs. The specimens were randomly divided into the following three groups of 10 samples each: group 1: the remaining canal space was filled with PBS as an intracanal dressing; group 2: the root segments were introduced in plastic vials containing floral foams with 20 mL of PBS; and group 3: the root segments were placed in the floral foams with 20 mL of PBS and a PBS intracanal dressing was used. After 2 months, the samples were processed for scanning electron microscopic observations. Data were analyzed by using the Kruskall-Wallis test.
  
  
  RESULTS
  In group 1, the formation of an interfacial layer (IL) with intratubular mineralization (ITM) was more evident at the cervical third; however, no mineralization was revealed at the apical third. In group 2, there was no IL and/or ITM formation at the cervical third, but samples denoted IL and ITM formation at the apical third. Group 3 displayed the formation of IL and ITM at the different levels.
  
  
  CONCLUSIONS
  It was concluded that the use of a PBS intracanal dressing promotes the biomineralization process at the inner side of MTA apical plugs.
authors.affiliation: Postgraduate Dentistry Program, Federal University of Santa Catarina, Florianópolis, SC, Brazil. jessreyesc@hotmail.com
authors.forename: Jessie F
authors.initials: JF
authors.lastname: Reyes-Carmona
authors.forename: Mara S
authors.initials: MS
authors.lastname: Felippe
authors.forename: Wilson T
authors.initials: WT
authors.lastname: Felippe
mesh_terms: D017607:Aluminum Compounds / Q000494:pharmacology*; D001031:Apatites / Q000378:metabolism; D056624:Apexification / Q000379:methods; D002021:Buffers; D017610:Calcium Compounds / Q000494:pharmacology*; D003804:Dentin / Q000187:drug effects; D004338:Drug Combinations; D006801:Humans; D008422:Materials Testing; D010087:Oxides / Q000494:pharmacology*; D010710:Phosphates / Q000494:pharmacology*; D012387:Root Canal Filling Materials / Q000494:pharmacology*; D012388:Root Canal Irrigants / Q000494:pharmacology*; D017640:Silicates / Q000494:pharmacology*; D012965:Sodium Chloride; D014089:Tooth Remineralization
chemical_list: D017607:Aluminum Compounds; D001031:Apatites; D002021:Buffers; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D010710:Phosphates; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D017640:Silicates; C086631:mineral trioxide aggregate; D012965:Sodium Chloride