title: Investigation of pH at different dentinal sites after placement of calcium hydroxide dressing by two methods.
abstract: OBJECTIVE
  The dentin pH at different sites following placement of calcium hydroxide paste using 2 different methods was evaluated.
  
  
  METHODS
  One hundred twenty Extracted teeth were instrumented and randomly divided into 6 different groups. Then they were dressed with calcium hydroxide by 2 different methods using paper points or Lentulo spiral, according to their respective groups, and stored. After the experimental period of time, half of the samples were cut transversally into slices and the other half split longitudinally and rinsed with distilled water. The dentin pH of cervical, middle, and apical thirds was measured from the root canal wall surface and 1 mm away from the root canal lumen in the inner dentin. The results were compared and statistically analyzed.
  
  
  RESULTS
  The highest pH values were obtained on the root canal walls when the calcium hydroxide was placed with Lentulo spiral filler (P > .05). There was a significant reduction in pH values in the inner dentin. When the cross sections of teeth were compared at 7 days, the Lentulo group was statistically different only in the apical third.
  
  
  CONCLUSIONS
  Placement of the calcium hydroxide paste with a Lentulo spiral with subsequent compaction with the blunt end of a sterile paper point obtained a higher pH value on the canal walls and in the inner dentin than paper points only.
authors.affiliation: Department of Endodontics, School of Dentistry, University of North Carolina at Chapel Hill, Manning Drive, 05 Brauer Hall, CB# 7450, Chapel Hill, NC 27599, USA. teixeirf@dentistry.unc.edu
authors.forename: Fabrício B
authors.initials: FB
authors.lastname: Teixeira
authors.forename: Linda G
authors.initials: LG
authors.lastname: Levin
authors.forename: Martin
authors.initials: M
authors.lastname: Trope
mesh_terms: D000704:Analysis of Variance; D002126:Calcium Hydroxide / Q000008:administration & dosage*; D003786:Dental Pulp Cavity / Q000737:chemistry; D003804:Dentin / Q000737:chemistry* / Q000378:metabolism; D003806:Dentin Permeability; D004058:Diffusion; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000493:pharmacokinetics; D016877:Oxidants / Q000493:pharmacokinetics; D011897:Random Allocation; D012388:Root Canal Irrigants / Q000008:administration & dosage*
chemical_list: D016877:Oxidants; D012388:Root Canal Irrigants; D017665:Hydroxyl Radical; D002126:Calcium Hydroxide