title: In vitro evaluation of the effect of dietary acids and toothbrushing on human root dentin permeability.
abstract: OBJECTIVE
  The purpose of this in vitro study was to quantify the alterations in human root dentin permeability after exposure to dietary acids and to evaluate the effect of toothbrushing after acid application.
  
  
  METHODS
  Extracted human third molars had their crowns sectioned above the CEJ, pulp tissue removed, and cervical root dentin exposed using a high-speed bur (approximately 1 mm in depth of substance loss). From each root fragment, one specimen was prepared. A total of 25 specimens were used and distributed randomly into five groups. The specimens were attached to a hydraulic pressure apparatus to evaluate the alterations of root dentin permeability after exposure to different acids. Dentin permeability was measured after the following sequential steps: (1) treatment with EDTA for 3 minutes to obtain the maximum permeability; (2) root planing to create a smear layer; (3) exposure to different acidic substances for 5 minutes (vinegar, cola drink, lemon juice, white wine, and orange juice); and (4) brushing for 3 minutes.
  
  
  RESULTS
  All acidic substances increased dentin permeability after root planing. Lemon juice produced higher values for permeability when compared to the other substances (P = .009); moreover, orange juice showed similar results (P < .02) except when compared to vinegar (P = .12). Brushing right after acid exposure significantly reduced dentin permeability except in the vinegar group (P = .07).
  
  
  CONCLUSIONS
  Under the experimental conditions, dietary acids increased root dentin permeability, and immediate brushing reduced permeability levels.
authors.affiliation: Department of Diagnostic and Oral Surgery, School of Dentistry at Araraquara, São Paulo State University, Araraquara, São Paulo, Brazil.
authors.forename: Daniela Leal
authors.initials: DL
authors.lastname: Zandim
authors.forename: Fabio Renato Manzolli
authors.initials: FR
authors.lastname: Leite
authors.forename: José Eduardo Cezar
authors.initials: JE
authors.lastname: Sampaio
mesh_terms: D019342:Acetic Acid / Q000009:adverse effects*; D000293:Adolescent; D000328:Adult; D001628:Beverages / Q000009:adverse effects*; D019343:Citric Acid / Q000009:adverse effects*; D003806:Dentin Permeability / Q000187:drug effects*; D003807:Dentin Sensitivity / Q000139:chemically induced / Q000517:prevention & control*; D006801:Humans; D018709:Statistics, Nonparametric; D019237:Tooth Cervix / Q000187:drug effects; D014092:Tooth Root / Q000187:drug effects; D014099:Toothbrushing; D055815:Young Adult
chemical_list: D019343:Citric Acid; D019342:Acetic Acid