title: An in situ study investigating dentine tubule occlusion of dentifrices following acid challenge.
abstract: OBJECTIVE
  To investigate the dentine occlusion and acid resistance of dentifrices developed to treat dentine hypersensitivity.
  
  
  METHODS
  This was a single centre, single blind, randomised, split mouth, four treatments, two period crossover, in situ study in healthy subjects. Subjects wore buccal intra-oral appliances each fitted with four dentine samples over four consecutive days with one study product applied per appliance; 8% strontium acetate in silica base, 1040 ppm sodium fluoride (Sensodyne(®) Rapid Relief), 8% arginine, calcium carbonate, 1450 ppm sodium monofluorophosphate (Colgate Sensitive Pro-Relief(®)), 1450 ppm sodium fluoride (control paste) and water. On days 3 and 4, two agitated grapefruit juice challenges (ex vivo) occurred for 1 min. At the end of each treatment day 1 dentine sample was removed from each appliance for scanning electron microscopy (SEM). The extent of tubule occlusion was measured using an examiner-based visual scoring index (three trained examiners).
  
  
  RESULTS
  In total, 28 subjects ((12 males and 16 females with a mean age of 34.7 years (SD 8.41 years)) completed the study. On day 2, both test dentifrices demonstrated significantly better dentine tubule occlusion than water (p < 0.0001) and control paste (8% strontium p = 0.0003 and 8% arginine p = 0.0019). After 3 and 4 days of twice daily brushing with acid challenges on days 3 and 4 the strontium-based dentifrice demonstrated significantly better dentine occlusion than all other treatments (p < 0.0001).
  
  
  CONCLUSIONS
  Strontium acetate and arginine-based dentifrice result in statistically significant dentine tubular occlusion compared to controls, but the arginine-based dentifrice is more susceptible to acid challenge.
  
  
  CONCLUSIONS
  Erosive beverages are an important aetiology in DH by exposing dentine tubules. Their consumption has increased significantly over the past decade in the UK. This 4-day in situ study investigated the properties of commercially available dentifrices designed to occlude dentine tubules and their resistance to an agitated acid challenge.
authors.affiliation: Department of Prosthodontics, King's College London Dental Institute, London, United Kingdom. ryan.olley@kcl.ac.uk
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Olley
authors.forename: Peter
authors.initials: P
authors.lastname: Pilecki
authors.forename: Nathan
authors.initials: N
authors.lastname: Hughes
authors.forename: Peter
authors.initials: P
authors.lastname: Jeffery
authors.forename: Rupert S
authors.initials: RS
authors.lastname: Austin
authors.forename: Rebecca
authors.initials: R
authors.lastname: Moazzez
authors.forename: David
authors.initials: D
authors.lastname: Bartlett
mesh_terms: D000085:Acetates / Q000627:therapeutic use; D000328:Adult; D001120:Arginine / Q000627:therapeutic use; D001628:Beverages; D002119:Calcium Carbonate / Q000627:therapeutic use; D002253:Carbonated Beverages; D002255:Carbonic Acid / Q000009:adverse effects; D019343:Citric Acid / Q000009:adverse effects; D032083:Citrus paradisi; D032084:Citrus sinensis; D018592:Cross-Over Studies; D003802:Dentifrices / Q000627:therapeutic use*; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D057133:Dentin Desensitizing Agents / Q000627:therapeutic use*; D005260:Female; D005459:Fluorides / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000627:therapeutic use; D016037:Single-Blind Method; D012969:Sodium Fluoride / Q000627:therapeutic use; D013324:Strontium / Q000627:therapeutic use
chemical_list: D000085:Acetates; D003802:Dentifrices; D057133:Dentin Desensitizing Agents; D010710:Phosphates; C012980:fluorophosphate; D019343:Citric Acid; D002255:Carbonic Acid; C106741:strontium acetate; D012969:Sodium Fluoride; D001120:Arginine; D002119:Calcium Carbonate; D005459:Fluorides; D013324:Strontium