Open AccessDental enamel bleached for a prolonged and excessive time: Morphological changes
Author(s) -
Kelly Fernanda Barbosa Vilhena,
Bárbara Catarina Lima Nogueira,
Nathália Carolina Fernandes Fagundes,
Sandro Cordeiro Loretto,
Rômulo Simões Angélica,
Rafael Rodrigues Lima,
Mário Honorato Silva e Souza
Publication year - 2019
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0214948
Subject(s) - enamel paint , tooth whitening , dentistry , indentation hardness , ultrastructure , scanning electron microscope , chemical composition , carbamide peroxide , surface roughness , chemistry , dental enamel , materials science , medicine , metallurgy , composite material , microstructure , anatomy , organic chemistry
This work aimed to evaluate the roughness, microhardness, ultrastructure, chemical composition and crystalline structure in submitted teeth to a prolonged home bleaching regimen with 10% carbamide peroxide (10% PC) for different periods. The specimens were divided into the following groups: G1: negative control (application of water-soluble gel); G2: tooth whitening group (positive control), under application time recommended by the manufacturer (4h/14 days); G3: prolonged whitening 50%, under prolonged time recommended by the manufacturer in 50% (4h/21 days); G4: excessive whitening 100%, under exceeded manufacturer recommended time by 100% (4h/ 28 days). The results were evaluated descriptively and analytically. There were no changes in the roughness in any of the evaluated groups. However, the microhardness decreased in the G4 group. Scanning electron microscopy showed changes in the enamel surface of groups G2, G3 and G4. Dispersive X-ray spectroscopy identified changes in the concentration of chemical elements O, Mg, P, K in all groups. Thus, this study showed that prolonged home bleaching could cause changes in the ultrastructure, chemical composition and microhardness of the enamel.