title: A qualitative assessment of non-carious cervical lesions in extracted human teeth.
abstract: BACKGROUND
  Opinions vary about the causes of non-carious cervical lesions (NCCLs). They have been attributed to toothbrush abrasion, acid corrosion (commonly termed dental erosion), and abfraction. The purpose of this study was to examine the microwear details of NCCLs in a collection of extracted human teeth using scanning election microscopy (SEM).
  
  
  METHODS
  Negative replicas of large NCCLs in 24 extracted human teeth were obtained in polyvinylsiloxane impression material (Light Body Imprint II, 3M ESPE) and viewed under SEM.
  
  
  RESULTS
  All NCCLs extended from the cemento-enamel junction to the root surface and they displayed a variety of wedge-shaped appearances. There was evidence of both abrasion and corrosion in 18 of the 24 teeth (75.0 per cent), abrasion only in one tooth (4.2 per cent) and corrosion only in five teeth (20.8 per cent). Horizontal furrows with smooth edges and minor scratch marks, characteristic of abrasion and corrosion, were noted in 13 teeth (54.2 per cent).
  
  
  CONCLUSIONS
  Based on microscopic assessment of a sample of extracted teeth, it appears that abrasion and corrosion are common associated aetiological factors in the formation of NCCLs.
authors.affiliation: School of Dentistry, The University of Adelaide, Adelaide, South Australia.
authors.forename: C
authors.initials: C
authors.lastname: Nguyen
authors.forename: S
authors.initials: S
authors.lastname: Ranjitkar
authors.forename: J A
authors.initials: JA
authors.lastname: Kaidonis
authors.forename: G C
authors.initials: GC
authors.lastname: Townsend
mesh_terms: D003760:Dental Impression Materials; D003804:Dentin / Q000473:pathology; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011145:Polyvinyls; D016628:Replica Techniques; D012833:Siloxanes; D014072:Tooth Abrasion / Q000473:pathology*; D019237:Tooth Cervix / Q000473:pathology* / Q000648:ultrastructure; D014077:Tooth Erosion / Q000473:pathology*; D014081:Tooth Extraction; D014092:Tooth Root / Q000473:pathology
chemical_list: D003760:Dental Impression Materials; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane