The Effect Of Use And Sterilization On Orthodontic Arch Wire On Load Deflection Characteristics
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Abstract
Objective: This study evaluated the influence of clinical use and subsequent steam sterilization on the load-deflection characteristics of superelastic Nickel-Titanium (NiTi) orthodontic archwires.
Materials and Methods: Forty-five 0.016-inch NiTi archwires were divided into three groups: Group 1 (As-received/Control), Group 2 (Retrieved after 4 weeks of clinical use), and Group 3 (Retrieved and sterilized at 134°C). Mechanical properties were assessed via a three-point bending test in a 37°C water bath. Loading and unloading forces were recorded at deflection intervals up to 3.0 mm. Data were analyzed using one-way ANOVA and Tukey’s post-hoc tests (p<0.05).
Results: Clinical use and sterilization significantly increased loading forces compared to the control (p<0.05). Conversely, the unloading plateau forces decreased by 12% in the retrieved group and 17% in the sterilized group. A higher incidence of permanent deformation was observed in the recycled groups.
Conclusion: Both clinical exposure and steam sterilization degrade the superelastic performance of NiTi archwires, leading to less predictable force delivery. Clinicians should be aware that reprocessing these wires may compromise treatment efficiency.
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References
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