Artigo
Mineral Loss and Morphological Changes in Dental Enamel Induced by a 16% Carbamide Peroxide Bleaching Gel
Registro en:
Brazilian Dental Journal. Fundação Odontológica de Ribeirão Preto, v. 24, n. 5, p. 517-521, 2013.
0103-6440
10.1590/0103-6440201302225
S0103-64402013000500517
S0103-64402013000500517.pdf
4517484241515548
Autor
Soares, Diana Gabriela
Ribeiro, Ana Paula Dias
Sacono, Nancy Tomoko
Loguercio, Alessandro Dourado
Hebling, Josimeri
Costa, Carlos Alberto De Souza
Resumen
The aim of this study was to compare the effect of a 16% carbamide peroxide (CP) gel and a 10% CP gel on mineralized enamel content and morphology. Enamel blocks from bovine incisors were subjected to a 14-day treatment (8 h/day) with 10% or 16% CP gels. Knoop microhardness was evaluated before bleaching and at 1, 7 or 14 days after this treatment (50 g/15 s). Mineral content (energy-dispersive x-ray spectroscopy), surface roughness and topography (atomic force microscopy) were evaluated at the 14-day period. Data were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). Significant microhardness reduction was observed at the 7 th and 14 th days for 10% CP gel, and for all bleaching times for 16% CP gel (p<0.05). At the 14-day period, a significant decrease in Ca and P content, increase on surface roughness (p<0.05) as well as on picks and valleys distance were observed when both bleaching gels were used. These enamel alterations were more intense for 16% CP gel. It was concluded that both CP-based gels promoted loss of mineral structure from enamel, resulting in a rough and porous surface. However, 16% CP gel caused the most intense adverse effects on enamel. O objetivo do presente estudo foi comparar o efeito de um gel com 16% de peróxido de carbamida (PC) sobre a estrutura mineral e morfologia do esmalte dental com os efeitos de um gel com 10% de PC. Blocos de esmalte provenientes de incisivos bovinos foram submetidos a 14 dias de tratamento (8 h/dia) com géis com 10 ou 16% de PC. A microdureza Knoop foi avaliada antes do clareamento e 1, 7 e 14 dias pós-tratamento (50 g/15 s). O conteúdo mineral (EDX), rugosidade de superfície e topografia (MFA) foram avaliados no período de 14 dias (ANOVA a dois critérios e teste de Tukey; α=0,05). Redução significante na microdureza foi observada nos períodos de 7 e 14 dias para o gel com 10% de PC, e em todos os períodos para o gel com 16% de PC (p<0,05). No período de 14 dias, uma diminuição significante no conteúdo de Ca e P, aumento na rugosidade de superfície (p<0,05), bem como na distância entre picos e vales foram observados para ambos os agentes clareadores usados. Estas alterações foram mais intensas para o gel com 16% de PC. Pôde-se concluir que ambos os géis à base de PC promoveram perda de estrutura mineral do esmalte, resultando em superfície mais rugosa e porosa. Porém, o gel com 16% de PC causou efeitos adversos mais intensos no esmalte dental. Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) UNESP - Univ Estadual Paulista Araraquara School of Dentistry Department of Dental Materials and Prosthodontics UNIB - University of Brasilia School of Dentistry Department of Dentistry UFG - Federal University of Goias School of Dentistry Department of Stomatological Sciences UEPG - State University of Ponta Grossa School of Dentistry Department of Restorative Dentistry UNESP Univ Estadual Paulista Araraquara School of Dentistry Department of Pediatric Dentistry and Orthodontics UNESP - Univ Estadual Paulista Araraquara School of Dentistry Department of Physiology and Pathology UNESP - Univ Estadual Paulista Araraquara School of Dentistry Department of Dental Materials and Prosthodontics UNESP Univ Estadual Paulista Araraquara School of Dentistry Department of Pediatric Dentistry and Orthodontics UNESP - Univ Estadual Paulista Araraquara School of Dentistry Department of Physiology and Pathology