title: The effect of calcium hydroxide placement on pH and calcium concentration in periapical environment: an in vitro study.
abstract: OBJECTIVE
  Comparing the calcium concentration and pH levels of Ca(OH) 2 medicament placing in pulp chamber and root canal.
  
  
  METHODS
  Ninety-nine extracted human mandibular second premolars were instrumented to size #40 k file. Nine teeth served as the control group and the remaining teeth were assigned into two groups. Group 1-Ca(OH) 2 was placed in the dried pulp chamber, while root canals remained wet with normal saline; group 2-Ca(OH) 2 was placed in dried root canals. In control group, canals remained wet without medication. Each group was divided into 3 sub-groups of 15 teeth in which pH and calcium concentration were measured in three intervals of 2 days, 1 week, and 2 weeks by pH meter and atomic absorption spectrometer system, respectively. Findings were assessed using Kruskal-Wallis and t-test.
  
  
  RESULTS
  At 1 and 2 weeks, the calcium concentration had increased without being significantly different from Ca(OH) 2 placed either in the root canal or in the pulp chamber. Ca(OH) 2 placed in the pulp chamber or root canal provided similar pH values (P=0.362).
  
  
  CONCLUSIONS
  Placing Ca(OH) 2 in pulp chamber is as effective as placing it in the root canal.
authors.affiliation: Department of Endodontics and Torabinejad Dental Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Behnaz
authors.initials: B
authors.lastname: Barekatain
authors.forename: Seyed Mohsen
authors.initials: SM
authors.lastname: Hasheminia
authors.forename: Elham
authors.initials: E
authors.lastname: Shadmehr
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Attary
mesh_terms: D001641:Bicuspid / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000032:analysis*; D002126:Calcium Hydroxide / Q000494:pharmacology*; D003786:Dental Pulp Cavity / Q000187:drug effects* / Q000378:metabolism; D003890:Desiccation; D006801:Humans; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D010486:Periapical Tissue / Q000187:drug effects / Q000378:metabolism; D012388:Root Canal Irrigants / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000379:methods; D012965:Sodium Chloride / Q000008:administration & dosage; D013054:Spectrophotometry, Atomic; D013696:Temperature; D013997:Time Factors
chemical_list: D012388:Root Canal Irrigants; D012965:Sodium Chloride; D002126:Calcium Hydroxide; D002118:Calcium