title: Demineralization and hydrogen peroxide penetration in teeth with incipient lesions.
abstract: The aim of this study was to evaluate the demineralization and hydrogen peroxide (HP) penetration in teeth with incipient lesions submitted to bleaching treatment. For analysis of HP penetration, sound and demineralized enamel/dentin discs were placed in artificial pulp chambers containing acetate buffer solution. After bleaching treatment, this solution was subjected for analysis of optical density by spectrophotometry and the disc surfaces were analyzed with scanning electron microscopy (SEM) and polarized light microscopy (PLM). The remaining discs were subjected for cross-sectional hardness analysis at different depths. Data were analyzed by repeated measures ANOVA and PLSD Fisher test (a=0.05). It was observed that previously demineralized teeth showed greater HP penetration (p<0.05). The bleaching treatment caused changes to a depth of 20 µm in sound enamel and up to 90 µm in demineralized enamel. SEM and PLM images revealed that the bleaching treatment caused superficial changes that were considerably more accentuated in previously demineralized teeth. It may be concluded that the enamel mineralization level influences HP penetration and the bleaching agent contributed to increase the demineralization depth.
authors.affiliation: Department of Restorative Dentistry, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: André Luiz Fraga
authors.initials: AL
authors.lastname: Briso
authors.affiliation: Department of Restorative Dentistry, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: Rafael Simões
authors.initials: RS
authors.lastname: Gonçalves
authors.affiliation: Department of Restorative Dentistry, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: Fernanda Bernardi da
authors.initials: FB
authors.lastname: Costa
authors.affiliation: Department of Restorative Dentistry, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: Marjorie de Oliveira
authors.initials: Mde O
authors.lastname: Gallinari
authors.affiliation: Department of Restorative Dentistry, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: Luciano Tavares Angelo
authors.initials: LT
authors.lastname: Cintra
authors.affiliation: Department of Dental Materials and Prosthodontics, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: Paulo Henrique dos
authors.initials: PH
authors.lastname: Santos
mesh_terms: D000818:Animals; D002417:Cattle; D003743:Dental Enamel / Q000187:drug effects*; D003786:Dental Pulp Cavity; D003806:Dentin Permeability / Q000187:drug effects*; D006244:Hardness; D006861:Hydrogen Peroxide / Q000737:chemistry*; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D014073:Tooth Bleaching / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000737:chemistry*; D017001:Tooth Demineralization
chemical_list: D058205:Tooth Bleaching Agents; D006861:Hydrogen Peroxide