title: Confocal laser scanning microscopy and area-scale analysis used to quantify enamel surface textural changes from citric acid demineralization and salivary remineralization in vitro.
abstract: OBJECTIVE
  This paper investigates the application of confocal laser scanning microscopy to determine the effect of acid-mediated erosive enamel wear on the micro-texture of polished human enamel in vitro.
  
  
  METHODS
  Twenty polished enamel samples were prepared and subjected to a citric acid erosion and pooled human saliva remineralization model. Enamel surface microhardness was measured using a Knoop hardness tester, which confirmed that an early enamel erosion lesion was formed which was then subsequently completely remineralized. A confocal laser scanning microscope was used to capture high-resolution images of the enamel surfaces undergoing demineralization and remineralization. Area-scale analysis was used to identify the optimal feature size following which the surface texture was determined using the 3D (areal) texture parameter Sa.
  
  
  RESULTS
  The Sa successfully characterized the enamel erosion and remineralization for the polished enamel samples (P<0.001).
  
  
  CONCLUSIONS
  Areal surface texture characterization of the surface events occurring during enamel demineralization and remineralization requires optical imaging instrumentation with lateral resolution <2.5 μm, applied in combination with appropriate filtering in order to remove unwanted waviness and roughness. These techniques will facilitate the development of novel methods for measuring early enamel erosion lesions in natural enamel surfaces in vivo.
authors.affiliation: King's College London Dental Institute, Guy's, King's and St. Thomas' Hospitals, London SE1 9RT, UK. Electronic address: rupert.s.austin@kcl.ac.uk.
authors.forename: R S
authors.initials: RS
authors.lastname: Austin
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK. Electronic address: claudiu.giusca@npl.co.uk.
authors.forename: C L
authors.initials: CL
authors.lastname: Giusca
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK. Electronic address: gavin.macaulay@npl.co.uk.
authors.forename: G
authors.initials: G
authors.lastname: Macaulay
authors.affiliation: King's College London Dental Institute, Guy's, King's and St. Thomas' Hospitals, London SE1 9RT, UK. Electronic address: rebecca.v.moazzez@kcl.ac.uk.
authors.forename: R
authors.initials: R
authors.lastname: Moazzez
authors.affiliation: King's College London Dental Institute, Guy's, King's and St. Thomas' Hospitals, London SE1 9RT, UK. Electronic address: david.bartlett@kcl.ac.uk.
authors.forename: D W
authors.initials: DW
authors.lastname: Bartlett
mesh_terms: D019343:Citric Acid / Q000494:pharmacology*; D006245:Hardness Tests; D006801:Humans; D021621:Imaging, Three-Dimensional; D066298:In Vitro Techniques; D018613:Microscopy, Confocal; D012463:Saliva; D013499:Surface Properties; D017001:Tooth Demineralization / Q000139:chemically induced; D014077:Tooth Erosion / Q000139:chemically induced; D014089:Tooth Remineralization / Q000379:methods*
chemical_list: D019343:Citric Acid
keywords: Enamel; Erosion; Imaging; Microhardness; Remineralization; Surface texture