Dental discoloration caused by bismuth oxide in MTA in the presence of sodium hypochlorite

Autor(es)

Marciano, Marina Angelica ^[1] ; Hungaro Duarte, Marco Antonio ^[1] ; Camilleri, Josette ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dent Sch Bauru, Dept Dent, Bauru, SP - Brazil

^[2] Univ Malta, Sch Med, Fac Dent Surg, Dept Restorat Dent, Msida 2090, Msd - Malta

• Tipo de documento: Artigo Científico
• Fonte: CLINICAL ORAL INVESTIGATIONS; v. 19, n. 9, p. 2201-2209, DEC 2015.
• Citações Web of Science: 27

Resumo

The aim of this research was to analyse the dental discolouration caused by mineral trioxide aggregate (MTA) induced by bismuth oxide and also assess the colour stability of other dental cements. Bismuth oxide, calcium tungstate and zirconium oxide were placed in contact with sodium hypochlorite for 24 h after which they were dried and photographed. Phase analyses were performed by X-ray diffraction (XRD) of radiopacifiers before and after immersion in sodium hypochlorite. Furthermore, teeth previously immersed in water or sodium hypochlorite were filled with MTA Angelus, Portland cement (PC), PC with 20 % zirconium oxide, PC with 20 % calcium tungstate and Biodentine. Teeth were immersed for 28 days in Hank's balanced salt solution after which they were sectioned and characterized using scanning electron microscopy (SEM) with energy-dispersive mapping and stereomicroscopy. Bismuth oxide in contact with sodium hypochlorite exhibited a change in colour from light yellow to dark brown. XRD analysis demonstrated peaks for radiopacifier and sodium chloride in samples immersed in sodium hypochlorite. The SEM images of the dentine to material interface showed alteration in material microstructure for MTA Angelus and Biodentine with depletion in calcium content in the material. The energy-dispersive maps showed migration of radiopacifier and silicon in dentine. MTA Angelus in contact with a tooth previously immersed in sodium hypochlorite resulted in colour alteration at the cement/dentine interface. MTA Angelus should not be used after irrigation with sodium hypochlorite as this will result in tooth discoloration. (AU)

• Processo FAPESP: 13/04054-8 - Análise da microestrutura e da interface de cimentos à base de silicato de cálcio contendo diferentes radiopacificadores
• Beneficiário: Marina Angélica Marciano da Silva
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 11/13573-3 - Propriedades físico-químicas e biológicas de cimento obturador experimental à base de Portland associado a diferentes radiopacificadores
• Beneficiário: Marina Angélica Marciano da Silva
• Modalidade de apoio: Bolsas no Brasil - Doutorado