title: The Effects of Alkaline pH on Microleakage of Mineral Trioxide Aggregate and Calcium Enriched Mixture Apical Plugs.
abstract: BACKGROUND
  Alkaline pH can affect the physical and chemical properties and sealing ability of apical plug material. Calcium hydroxide is used as an intracanal medication to complete disinfection of root canals. It raises the pH of environment to alkaline value.
  
  
  OBJECTIVE
  The aim of this in vitro study was to evaluate and compare the effect of alkaline pH on the sealing ability of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA) apical plugs.
  
  
  METHODS
  Seventy single-rooted human maxillary anterior teeth were randomly divided to two experimental groups for Angelus MTA and CEM cement (n=30) and two control groups (n=5). Each group was divided into two subgroups of 15 for neutral and alkaline pH, and 1 negative and 1 positive control groups of 5. The root canals were cleaned and shaped by using ProTaper rotary system (Dentsply Maillefer; Ballaigues, Switzerland) and the terminal 3mm of the roots were resected. Then, MTA and CEM cement were condensed in apical region with 3mm thickness. The samples were exposed to two environments with different pH values of 13 and 7.4. The leakage was assessed by using the fluid filtration technique at 1, 7, 14, 30 days intervals. Data were analyzed by the repeated measures MANOVA.
  
  
  RESULTS
  There was no statistically significant difference in the rate of microleakage between neutral and alkaline pH of CEM cement and MTA (p> 0.05). The sealing ability of MTA in an alkaline pH of 13 was significantly less than CEM cement in this pH (p< 0.05).
  
  
  CONCLUSIONS
  An environment with alkaline pH had no adverse effect on the sealing ability of MTA and CEM cement used as apical plugs. CEM cement had better sealing ability in alkaline pH.
authors.affiliation: Dept. of Endodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Mirhadi
authors.affiliation: Dept. of Endodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Fariborz
authors.initials: F
authors.lastname: Moazzami
authors.affiliation: Student Research Committee, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Rangani Jahromi
authors.affiliation: Student Research Committee, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Sareh
authors.initials: S
authors.lastname: Safarzade
keywords: Alkaline pH; Apical Plug; Calcium Enriched Mixture Cement; Fluid Filtration; Microleakage; Mineral Trioxide Aggregate; Sealing Ability