METAL RELEASE FROM BRACKETS AND ARCHWIRES

BRACKET과 호선의 금속유리

The purpose of this experiment was to measure the amounts of nickel and chromium released from a simulated orthodontic appliance in artificial saliva. Simulated mandibular half-arch orthodontic appliances were composed of American Iron and Steel Institute type 304 brackets, Permachrome, Elgiloy, Australian wire, T.M.A. and Nitinol. The amounts of nickel and chromium released from sample were measured with atomic absorption spectrophotometer after 3, 6, 9, 12, 15 days. The cumulative amounts of nickel released from Permachrome, Elgiloy, Australian wire and T.M.A. reached a plateau after 6 days. But the cumulative amounts of nickel released from Nitinol increased continuously. Significant amounts of both nickel and chromium were solubilized from the simulated orthodontic appliances into artificial saliva. After 15 days, total cumulative amounts of nickel were $152.15{\mu}g$, $150.27{\mu}g$, $134.74{\mu}g$, $114.67{\mu}g$ and $93.39{\mu}$ from the Elgiloy, Australian wire, Nitinol, Permachrome and T.M.A., respectively. Total cumulative amounts of chromium from Permachrome, Australian wire, Elgiloy, Nitinol and T.M.A. were $100.83{\mu}g$, $83.64{\mu}g$, $81.61{\mu}g$, $14.90{\mu}g$ and $12.43{\mu}g$, respectively. The result showed that nickel released from Elgiloy and chromium released from Permachrome were more than any others.