title: Chlorhexidine and green tea extract reduce dentin erosion and abrasion in situ.
abstract: OBJECTIVE
  This in situ/ex vivo study aimed to analyse the impact of possible MMP-inhibitors (chlorhexidine and green tea extract) on dentin wear induced by erosion or erosion plus abrasion.
  
  
  METHODS
  Twelve volunteers took part in this cross-over and double-blind study performed in 4 phases of each 5 days. Bovine dentin samples were worn in palatal appliances and subjected to extraoral erosion (4 times/day, Coca-Cola, 5 min) or erosion plus abrasion (2 times/day, fluoride-free toothpaste and electrical toothbrush, 15s/sample). Immediately after each erosion, the appliances were reinserted in the mouth and the oral cavity was rinsed for 60s with: 250 ppm F solution (SnF(2)/AmF, pH 4.5, Meridol-Gaba, Switzerland), 0.12% chlorhexidine digluconate (0.06% chlorhexidine, pH 6.0, Periogard-Colgate, Brazil), 0.61% green tea extract solution (OM24, 100% Camellia Sinensis leaf extract, catechin concentration: 30+/-3%, pH 7.0, Omnimedica, Switzerland) or deionized water (pH 6.0, control). Dentin loss was assessed by profilometry (microm). The data were analysed by two-way repeated measures ANOVA and Bonferroni post hoc test.
  
  
  RESULTS
  There was a significant difference between the conditions (EroxEro+Abr, p<0.001) and among the solutions (p<0.001). All solutions (F: 1.42+/-0.34; 1.73+/-0.50, chlorhexidine: 1.15+/-0.26; 1.59+/-0.32, green tea: 1.06+/-0.30; 1.54+/-0.55) significantly reduced the dentin wear when compared to control (2.00+/-0.55; 2.41+/-0.83) for both conditions. There were not significant differences among green tea extract, chlorhexidine and F solutions.
  
  
  CONCLUSIONS
  Thus, the possible MMP-inhibitors tested in this study seem to be a promising preventive measure to reduce dentin erosion-abrasion, but their mechanism of action needs to be investigated in further studies.
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Magalhães
authors.forename: Annette
authors.initials: A
authors.lastname: Wiegand
authors.forename: Daniela
authors.initials: D
authors.lastname: Rios
authors.forename: Angélica
authors.initials: A
authors.lastname: Hannas
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.forename: Marília Afonso Rabelo
authors.initials: MA
authors.lastname: Buzalaf
mesh_terms: D000328:Adult; D000588:Amines / Q000627:therapeutic use; D000818:Animals; D028241:Camellia sinensis; D002253:Carbonated Beverages / Q000009:adverse effects; D002392:Catechin / Q000627:therapeutic use; D002417:Cattle; D002710:Chlorhexidine / Q000627:therapeutic use*; D018592:Cross-Over Studies; D003804:Dentin / Q000187:drug effects; D004311:Double-Blind Method; D004338:Drug Combinations; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors; D009067:Mouthwashes / Q000627:therapeutic use; D010936:Plant Extracts / Q000627:therapeutic use*; D011446:Prospective Studies; D014002:Tin Fluorides / Q000627:therapeutic use; D014072:Tooth Abrasion / Q000517:prevention & control*; D014077:Tooth Erosion / Q000517:prevention & control*; D014099:Toothbrushing / Q000009:adverse effects; D055815:Young Adult
chemical_list: D000588:Amines; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D009067:Mouthwashes; D010936:Plant Extracts; D014002:Tin Fluorides; C059813:Meridol; D002392:Catechin; D002710:Chlorhexidine