| Autor: |
Moura CW; Universidade de Taubaté. Departamento de Odontologia, Taubaté, São Paulo, Brasil., Catelan A; Universidade de Taubaté. Departamento de Odontologia, Taubaté, São Paulo, Brasil., Zanatta RF; Universidade de Taubaté. Departamento de Odontologia, Taubaté, São Paulo, Brasil. zanatta.rayssa@gmail.com., Cavalcanti AN; Universidade Federal da Bahia, Faculdade de Medicina e Saúde Pública da Bahia, Área de Odontologia Restauradora, Salvador, Bahia, Brasil., Soares LE; Universidade do Vale do Paraíba, Instituto de Pesquisa e Desenvolvimento, Laboratório de Odontologia e Materiais Aplicados, São José dos Campos, São Paulo, Brasil., Martins KV; Universidade de Taubaté. Departamento de Odontologia, Taubaté, São Paulo, Brasil., Liporoni PC; Universidade de Taubaté. Departamento de Odontologia, Taubaté, São Paulo, Brasil.; Universidade de Campinas, Faculdade de Odontologia de Piracicaba, Departamento de Odontologia Restauradora, Piracicaba, São Paulo, Brasil. |
| Abstrakt: |
This study evaluated enamel mineral content and surface microhardness before and after bleaching treatment using 10% carbamide peroxide (CP) containing calcium (Ca) or amorphous calcium phosphate (ACP). Thirtysix bovine slabs were randomly allocated into 3 groups (n = 12) according to bleaching treatment: G1 Opalescence PF 10% (CP), G2 NiteWhite ACP (CP+ACP), and G3 Opalescence PF (10%) with calcium (CP+CA). The bleaching agent was applied on enamel surface for 6 h/day over a period of 21 days. Enamel surface was evaluated by Knoop microhardness (KNH) and micro energydispersive Xray fluorescence spectrometry (μEDXRF) at baseline and at after bleaching treatment. Data were statistically analyzed by repeated measures ANOVA and Tukey's test (α = 0.05). There was a significant decrease in microhardness after bleaching treatments for all study groups, but no difference between bleaching gels. There was no difference in the Ca/P ratio measured by μEDXRF for all groups at the study times, but the mean value was lower in group CP+CA than in group CP+ACP. Group CP was similar to both CP+ACP and CP+CA. It can be concluded that enamel microhardness decreased after the bleaching process, regardless of the presence of calcium or ACP, but there was no significant change in the Ca/P ratio of enamel after bleaching for each tested gel. This indicates that the bleaching gels have erosive potential, causing softening of enamel without promoting surface loss, regardless of the presence of calcium of ACP ions. |
