BACKGROUND: Increased concentrations of nickel ions may be released into saliva from recycled NiTi archwires. AIM: To compare the nickel ion concentrations released from recycled NiTi wires after sterilisation by either dry heat or steam autoclave. METHODS: Eighty preformed NiTi wires were assigned to four equal groups. In Groups 1, 2 and 3 the archwires were used intra-orally for 4 weeks. The Group 4 archwires were not used. Group 1 archwires were sterilised by dry heat, the Group 2 archwires were sterilised by steam autoclave, the Group 3 archwires were not sterilised and the Group 4 archwires were as-received. A 2 cm length, cut from each archwire, was immersed in artificial saliva for 4 weeks and the nickel ion concentrations in the artificial saliva measured with an atomic absorption spectrophotometer. RESULTS: There were no significant differences in the nickel ion concentrations released into the artificial saliva by each group of archwires (p = 0.467). CONCLUSION: Sterilisation of used NiTi wires by either dry heat and steam autoclave does not affect the concentrations of nickel ions released into artificial saliva.
BACKGROUND: Increased concentrations of nickel ions may be released into saliva from recycled NiTi archwires. AIM: To compare the nickel ion concentrations released from recycled NiTi wires after sterilisation by either dry heat or steam autoclave. METHODS: Eighty preformed NiTi wires were assigned to four equal groups. In Groups 1, 2 and 3 the archwires were used intra-orally for 4 weeks. The Group 4 archwires were not used. Group 1 archwires were sterilised by dry heat, the Group 2 archwires were sterilised by steam autoclave, the Group 3 archwires were not sterilised and the Group 4 archwires were as-received. A 2 cm length, cut from each archwire, was immersed in artificial saliva for 4 weeks and the nickel ion concentrations in the artificial saliva measured with an atomic absorption spectrophotometer. RESULTS: There were no significant differences in the nickel ion concentrations released into the artificial saliva by each group of archwires (p = 0.467). CONCLUSION: Sterilisation of used NiTi wires by either dry heat and steam autoclave does not affect the concentrations of nickel ions released into artificial saliva.