title: Medication with calcium hydroxide improved marginal adaptation of mineral trioxide aggregate apical barrier.
abstract: BACKGROUND
  The purpose of this study was to evaluate the effect of calcium hydroxide premedication on the marginal adaptation of the mineral trioxide aggregate (MTA) apical barrier.
  
  
  METHODS
  Forty single-rooted teeth were prepared and apically resorbed using sulfuric acid for 4 days. Teeth were allocated into two groups according to whether calcium hydroxide was placed in the canals for 1 week (medicated group) or not (nonmedicated group) before placing a 4-mm MTA apical plug in the canals. The roots were mounted on aluminum stubs, the root apex was viewed from the top under scanning electron microscopy, and the maximum distance between MTA and the surrounding dentin was measured.
  
  
  RESULTS
  The mean gap widths in the medicated and nonmedicated groups were 70.2 μm and 130.0 μm, respectively (p < 0.05).
  
  
  CONCLUSIONS
  Calcium hydroxide treatment improves marginal adaptation of the MTA apical plug.
authors.affiliation: Dental Research Center of Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Bidar
authors.forename: Reza
authors.initials: R
authors.lastname: Disfani
authors.forename: Salman
authors.initials: S
authors.lastname: Gharagozloo
authors.forename: Shirin
authors.initials: S
authors.lastname: Khoynezhad
authors.forename: Armita
authors.initials: A
authors.lastname: Rouhani
mesh_terms: D017607:Aluminum Compounds; D056624:Apexification / Q000379:methods*; D017610:Calcium Compounds; D002126:Calcium Hydroxide / Q000008:administration & dosage*; D018772:Dental Marginal Adaptation; D004338:Drug Combinations; D006801:Humans; D010087:Oxides; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D017640:Silicates
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D017640:Silicates; C086631:mineral trioxide aggregate; D002126:Calcium Hydroxide