title: Microscopic appearance of enamel white-spot lesions after acid etching.
abstract: Ultrastructural changes in surface characteristics of enamel white-spot lesions were compared with changes in the adjacent clinically sound enamel after they were etched with 30% phosphoric acid. Ten human permanent first molars exhibiting natural white-spot lesions were used as study specimens. The lesion surfaces and their adjacent sound enamel were etched with 30% phosphoric acid for 60 seconds. Specimens were then evaluated by polarized light microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The acid etching produced a porous surface on both the white-spot lesion and the surrounding sound enamel. However, the lesion surface appeared to be more resistant to acid and dissolved less than adjacent enamel. This difference in acid solubility produced a steplike appearance between a white-spot lesion and its adjacent enamel surface. Energy-dispersive spectroscopy demonstrated no difference in relative calcium-phosphorus ratios among the acid-etched white-spot lesion, acid-etched sound enamel, and unetched sound enamel.
authors.affiliation: Department of Oral Biology and Endodontics, University of Missouri-Kansas City, School of Dentistry, USA.
authors.forename: C Q
authors.initials: CQ
authors.lastname: Lee
authors.forename: Z
authors.initials: Z
authors.lastname: Shey
authors.forename: C M
authors.initials: CM
authors.lastname: Cobb
mesh_terms: D000134:Acid Etching, Dental; D002118:Calcium / Q000032:analysis; D003731:Dental Caries / Q000473:pathology*; D003743:Dental Enamel / Q000737:chemistry / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D003747:Dental Enamel Solubility; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008859:Microscopy, Polarization; D008963:Molar; D010756:Phosphoric Acids / Q000494:pharmacology; D010758:Phosphorus / Q000032:analysis; D011897:Random Allocation; D013057:Spectrum Analysis / Q000379:methods; D013499:Surface Properties; D017001:Tooth Demineralization / Q000473:pathology
chemical_list: D010756:Phosphoric Acids; D010758:Phosphorus; C030242:phosphoric acid; D002118:Calcium