Artigo Produção Nacional Revisado por pares

Effects of phosphoric acid on bovine enamel bleached with carbamide peroxide

2008; Wiley; Volume: 116; Issue: 1 Linguagem: Inglês

10.1111/j.1600-0722.2007.00497.x

ISSN

1600-0722

Autores

Carmen Lúcia Soares Gomes de Medeiros, Santiago González‐López, María Victoria Bolaños-Carmona, Purificación Sánchez-Sánchez, Jorge Bolaños‐Carmona,

Tópico(s)

Dental materials and restorations

Resumo

The aim of this study was to measure the demineralization capacity of 37% phosphoric acid on bovine enamel at different time‐points after bleaching with 30% carbamide peroxide. Five, 4 × 4‐mm sections were obtained from the enamel of 10 bovine incisors. After applying 30% carbamide peroxide (Vivastyle) for 90 min, specimens were stored in artificial saliva for 0, 24, 72 h, or 7 d and then immersed in 37% phosphoric solution. At 15, 30, 60, 90, and 120 s, 5‐ml aliquots were extracted. A control group of specimens was not bleached. Ca 2+ concentrations were measured by atomic absorption spectrophotometry. A larger amount of Ca 2+ was extracted from enamel by phosphoric acid after the application of 30% carbamide peroxide. Twenty‐four hours after bleaching, significantly more Ca 2+ was extracted from bleached than from control specimens at all time‐points, and this greater susceptibility to the action of the acid persisted for at least 1 wk after bleaching.

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