Ultrastructural evaluation of enamel after dental bleaching associated with fluoride

• Published in: Microscopy research and technique 2012-08, Vol.75 (8), p.1093-1098
• Main Authors: Dominguez, John A., Bittencourt, Bruna, Michel, Milton, Sabino, Nilson, Gomes, João Carlos, Gomes, Osnara M. M.
• Format: Article
• Language: English
• Subjects: Dental Enamel - drug effects; Dental Enamel - ultrastructure; Dental Stress Analysis - methods; Elastic Modulus; fluoride; Fluorides, Topical - administration & dosage; Fluorides, Topical - pharmacology; Hardness; Humans; hydrogen peroxide; Hydrogen Peroxide - administration & dosage; Hydrogen Peroxide - pharmacology; Hydrogen-Ion Concentration; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Random Allocation; Saliva, Artificial - administration & dosage; Saliva, Artificial - pharmacology; Surface Properties; tooth bleaching; Tooth Bleaching - methods; Tooth Bleaching Agents - administration & dosage; Tooth Bleaching Agents - pharmacology; Tooth Erosion - chemically induced; Tooth Erosion - pathology
• ISSN: 1059-910X; 1097-0029
• DOI: 10.1002/jemt.22035

This study evaluated the effects on human enamel after two bleaching procedures: with a fluoridated bleaching agent and with topical fluoride application postbleaching. It used 43 enamel blocks (3 mm2) that were ground flat (600–2,000 grit) and polished with polishing paste (one and one‐fourth). Specimens were randomly divided into three groups according to the bleaching procedure: (1) control group, (2) hydrogen peroxide 35% (HPF) and topical application of fluoride 1.23%, and (3) HP 38% (OP) with fluoride in its composition. Bleaching agents were used according to the manufacturer's instructions. Three methodologies were used: nanoindentation, to observe surface hardness and elastic modulus; atomic force microscopy, to observe surface roughness (Ra − Rz); and scanning electron microscopy, to observe the enamel surface effects. Group OP had a decrease in the elastic modulus after bleaching, which was recovered at 14 days. An increased roughness (Ra; 32%) was observed on group HPF and had an increased erosion on enamel surface (67%). It was concluded that topical application of fluoride, after using the nonfluoridated whitening agent, increased the roughness values and erosion of enamel. Microsc. Res. Tech. 75:1093–1098, 2012. © 2012 Wiley Periodicals, Inc.