Corrosion resistance of Ni-Cr alloys in different mouthwashes

• Autor(a) principal: Rezende, Maria Cristina Rosifini Alves [UNESP]
• Data de Publicação: 2011
• Outros Autores: Grandini, Carlos Roberto [UNESP], Dekon, Stefan Fiuza de Carvalho [UNESP], Bertoz, André Pinheiro de Magalhães [UNESP], Dutra, Conceição Aparecida Matsumoto [UNESP], Codaro, Eduardo Norberto [UNESP], Alves-Claro, Ana Paula Rosifini [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://apcdaracatuba.com.br/revista/v32n12011/v32n12011.htm; http://hdl.handle.net/11449/133344
• topic: Corrosion; Titanium; Mouthwashes; Corrosão; Titânio; Antisséptcos bucais

Several alloys have been used for prosthodontics restorations in the last years. These alloys have a number of metals that include gold, palladium, silver, nickel, cobalt, chromium and titanium and they are used in oral cavity undergo several corrosion. Corrosion can lead to poor esthetics, compromise of physical properties, or increased biological irritation. The objective of this study was evaluated corrosion resistance of two alloys Ni-Cr and Ni-Cr-Ti in three types of mouthwashes with different active ingredients: 0.5g/l cetylpyridinium chloride + 0.05% sodium fluoride, 0.05% sodium fluoride + 0.03% triclosan (with fluor) and 0.12% chlorohexidine digluconate. The potentiodynamic curves were performed by means of an EG&G PAR 283 potentiostat/galvanostat. The counter electrode was a platinum wire and reference electrode was an Ag/AgCl, KCl saturated. Before each experiment, working electrodes were mechanically polished with 600 and 1200 grade papers, rinsed with distilled water and dried in air. All experiments were carried out at 37.0oC in conventional three-compartment double wall glass cell containing mouthwashes. The microstructures of two alloys were observed in optical microscopy. Analysis of curves showed that Ni-Cr alloy was less reactive in the presence of 0.12% chlorohexidine digluconate while Ni-Cr-Ti alloy was more sensitive for others two types of mouthwashes (0.5g/l cetylpyridinium chloride + 0.05% sodium fluoride  and 0.05% sodium fluoride + 0.03% triclosan). This occurred probably due presence of titanium in this alloy. Microstructural analysis reveals the presence of dendritic and eutectic microstructures for NiCr and Ni-Cr-Ti, respectively.