title: Analysis of the Early Stages and Evolution of Dental Enamel Erosion.
abstract: The aim of this study was to evaluate by atomic force microscopy (AFM) the early phases and evolution of dental enamel erosion caused by hydrochloric acid exposure, simulating gastroesophageal reflux episodes. Polished bovine enamel slabs (4x4x2 mm) were selected and exposed to 0.1 mL of 0.01 M hydrochloric acid (pH=2) at 37 ?#61472;?#61616;C using five different exposure intervals (n=1): no acid exposure (control), 10 s, 20 s, 30 s and 40 s. The exposed area was analyzed by AFM in 3 regions to measure the roughness, surface area and morphological surface. The data were analyzed qualitatively. Roughness started as low as that of the control sample, Rrms=3.5 nm, and gradually increased at a rate of 0.3 nm/s, until reaching Rrms=12.5 nm at 30 s. After 40 s, the roughness presented increment of 0.40 nm only. Surface area (SA) increased until 20 s, and for longer exposures, the surface area was constant (at 30 s, SA=4.40 μm2 and at 40 s, SA=4.43 μm2). As regards surface morphology, the control sample presented smaller hydroxyapatite crystals (22 nm) and after 40 s the crystal size was approximately 60 nm. Short periods of exposure were sufficient to produce enamel demineralization in different patterns and the morphological structure was less affected by exposure to hydrochloric acid over 30 s.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, USP - Universidade de São Paulo, Ribeirão Preto, SP, Brazil, Universidade de São Paulo, Universidade de São Paulo, Ribeirão Preto SP , Brazil.
authors.forename: Juliana Dos Reis
authors.initials: Jdos R
authors.lastname: Derceli
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, USP - Universidade de São Paulo, Ribeirão Preto, SP, Brazil, Universidade de São Paulo, Universidade de São Paulo, Ribeirão Preto SP , Brazil.
authors.forename: Juliana Jendiroba
authors.initials: JJ
authors.lastname: Faraoni
authors.affiliation: São Carlos Physics Institute, USP - Universidade de São Paulo, São Carlos, SP, Brazil, Universidade de São Paulo, Universidade de São Paulo, São Carlos SP , Brazil.|UNICEP - Paulista Central University Center, São Carlos, SP, Brazil, Centro Universitário Central Paulista, Paulista Central University Center, São Carlos SP , Brazil.
authors.forename: Marcelo Assumpção
authors.initials: MA
authors.lastname: Pereira-da-Silva
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, USP - Universidade de São Paulo, Ribeirão Preto, SP, Brazil, Universidade de São Paulo, Universidade de São Paulo, Ribeirão Preto SP , Brazil.
authors.forename: Regina Guenka
authors.initials: RG
authors.lastname: Palma-Dibb
mesh_terms: D000818:Animals; D002417:Cattle; D003743:Dental Enamel; D006801:Humans; D066298:In Vitro Techniques; D018625:Microscopy, Atomic Force; D014077:Tooth Erosion / Q000209:etiology*