An in vitro comparison of nickel and chromium release from brackets

• Autor(a) principal: Haddad,Ana Cristina Soares Santos
• Data de Publicação: 2009
• Outros Autores: Tortamano,Andre, Souza,Alexandre Luís de, Oliveira,Pedro Vitoriano de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Oral Research
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1806-83242009000400009
• topic: Orthodontic brackets; Nickel; Chromium; Saliva; artificial

This study aimed at comparing amounts of nickel (Ni) and chromium (Cr) released from brackets from different manufacturers in simulated oral environments. 280 brackets were equally divided into 7 groups according to manufacturer. 6 groups of brackets were stainless steel, and 1 group of brackets was made of a cobalt-chromium alloy with low Ni content (0.5%). International standard ISO 10271/2001 was applied to provide test methods. Each bracket was immersed in 0.5 ml of synthetic saliva (SS) or artificial plaque fluid (PF) over a period of 28 days at 37ºC. Solutions were replaced every 7 days, and were analyzed by spectrometry. The Kruskal-Wallis test was applied. Amounts of Ni release in SS (µg L-1 per week) varied between groups from "bellow detection limits" to 694, and from 49 to 5,948.5 in PF. The group of brackets made of cobalt-chromium alloy, with the least nickel content, did not release the least amounts of Ni. Amounts of Cr detected in SS and in PF (µg L-1 per week) were from 1 to 10.4 and from 50.5 to 8,225, respectively. It was therefore concluded that brackets from different manufacturers present different corrosion behavior. Further studies are necessary to determine clinical implications of the findings.