title: Toothbrushing before or after an acidic challenge to minimize tooth wear? An in situ/ex vivo study.
abstract: OBJECTIVE
  To evaluate whether patients should be advised to perform toothbrushing before or after an acidic challenge to minimize enamel and dentin wear by brushing abrasion.
  
  
  METHODS
  The study was a two-period crossover design (A and B, each 14 days) in which three enamel and dentin specimens were fixed in intraoral appliances of 10 volunteers. The following regimens were performed three times a day with at least 4 hours in between: A: 20-second brushing treatment in an automatic brushing machine, 5 minutes intraoral exposure of the specimens, extraoral erosion of enamel and dentin specimens for 40 seconds or B: Extraoral erosion for 40 seconds, 5 minutes intraoral exposure of the specimens, 20-second brushing treatment in an automatic brushing machine. Enamel and dentin loss at the end of each 14-day regimen was assessed by profilometry and statistically analyzed by t-test.
  
  
  RESULTS
  For all volunteers, mean enamel and dentin wear was significantly lower when brushing treatment was performed before erosion (A: enamel: 2.3 +/- 1.0 microm, dentin: 4.1 +/- 1.6 microm) than when brushing was applied after erosion (B: enamel: 6.4 +/- 3.0 microm, dentin: 15.3 +/- 6.8 microm). It was concluded that patients awaiting an erosive attack should perform toothbrushing prior to rather than after an acidic challenge to minimize enamel and dentin wear.
authors.affiliation: Clinic for Preventive Dentistry, Periodontology and Cariology, University of Zürich, Plattenstrasse 11, CH-8032 Zürich, Switzerland. annette.wiegand@zzmk.unizh.ch
authors.forename: Annette
authors.initials: A
authors.lastname: Wiegand
authors.forename: Sebastian
authors.initials: S
authors.lastname: Egert
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
mesh_terms: D000143:Acids; D000328:Adult; D000818:Animals; D002253:Carbonated Beverages / Q000009:adverse effects*; D002327:Cariostatic Agents / Q000627:therapeutic use; D002417:Cattle; D018592:Cross-Over Studies; D003743:Dental Enamel / Q000187:drug effects* / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D005260:Female; D005459:Fluorides / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D012464:Saliva, Artificial; D013997:Time Factors; D014072:Tooth Abrasion / Q000473:pathology / Q000517:prevention & control*; D014077:Tooth Erosion / Q000209:etiology; D014099:Toothbrushing / Q000379:methods*; D014100:Toothpastes / Q000627:therapeutic use
chemical_list: D000143:Acids; D002327:Cariostatic Agents; D012464:Saliva, Artificial; D014100:Toothpastes; D005459:Fluorides