Assessment of Color Stability of White Mineral Trioxide Aggregate Angelus and Bismuth Oxide in Contact with Tooth Structure

Autor(es)

Marciano, Marina Angelica ^[1] ; Costa, Reginaldo Mendonca ^[1] ; Camilleri, Josette ^[2] ; Lia Mondelli, Rafael Francisco ^[1] ; Guimaraes, Bruno Martini ^[1] ; Hungaro Duarte, Marco Antonio ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Bauru Dent Sch, Dept Restorat Dent Dent Mat & Endodont, Sao Paulo - Brazil

^[2] Univ Malta, Dept Restorat Dent, Msida - Malta

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ENDODONTICS; v. 40, n. 8, p. 1235-1240, AUG 2014.
• Citações Web of Science: 62

Resumo

Introduction: Dental discoloration with use of materials containing bismuth oxide has been reported. It is postulated that the discoloration is a result of chemical interaction of bismuth oxide with dentin. The aim of the study was to analyze dental color alteration and the chemical interaction of bismuth oxide with the main components present in composite (methacrylate) and in dentin (collagen). Methods: Fifty bovine teeth were prepared and filled with white mineral trioxide aggregate (MTA) Angelus, Portland cement (PC) with 20% zirconium oxide, or PC with 20% calcium tungstate and then sealed with composite. Triple antibiotic paste and unfilled samples were the positive and negative controls, respectively. The specimens were stored in separate flasks immersed in tap water at 37 degrees C with ambient light blocked out. The color assessment was performed with a spectrophotometer at different intervals, namely before filling and 24 hours, 15 days, and 30 days after filling. The color change and the luminosity were calculated. The statistical analysis was performed by using nonparametric Kruskal-Wallis and Dunn tests (P < .05). The interaction of the bismuth oxide, zirconium oxide, and calcium tungstate with collagen and methacrylate was assessed by placing the materials in contact, followed by color assessment. Results: The analysis of color change values showed that all the materials presented color alteration after the evaluated periods. Statistically higher luminosity was verified for PC/20% zirconium oxide in comparison with white MTA Angelus (P < .05). The teeth filled with white MTA Angelus demonstrated a grayish discoloration with evident dentin staining. Bismuth oxide exhibited a color change when in contact with collagen. Conclusions: The color of white MTA Angelus was altered in contact with dental structures. Collagen, which is present in dentin matrix, reacted with bismuth oxide, resulting in a grayish discoloration. The use of an alternative radiopacifier to replace bismuth in white MTA is indicated. (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: 12/06738-9 - Avaliação de materiais, instrumentos e protocolos de irrigação empregados no tratamento endodôntico, por meio da microscopia eletrônica de varredura e micro análise de raios X.
• Beneficiário: Marco Antonio Hungaro Duarte
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• 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