Effect of temperature on the orthodontic clinical applications of niti closed-coil springs

NiTi spring coils were used to obtain large deformation under a constant force. The device consists on a NiTi coil spring, superelastic at body temperature, in order to have a stress plateau during the austenitic retransformation during the unloading. The temperature variations induced changes in th...

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Detalles Bibliográficos
Autores: Espinar-Escalona, E., Llamas, J.M., Barrera Mora, José María, Ábalos Labruzzi, Camilo Manuel, Gil Mur, Javier
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2013
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/32738
Acceso en línea:http://hdl.handle.net/11441/32738
https://doi.org/10.4317/medoral.19073
Access Level:acceso abierto
Palabra clave:Superelasticity
NiTi
Springs
Orthodontic
Coils
Recovery
Temperature
Descripción
Sumario:NiTi spring coils were used to obtain large deformation under a constant force. The device consists on a NiTi coil spring, superelastic at body temperature, in order to have a stress plateau during the austenitic retransformation during the unloading. The temperature variations induced changes in the spring force. Objectives: The aim of this study is to investigate the effect of the temperature variations in the spring forces and corrosion behaviour simulating the ingestion hot/cold drinks and food. Study Design: The springs were subjected to a tensile force using universal testing machine MTS-Adamel (100 N load cell). All tests were performed in artificial saliva maintained at different temperatures. The corrosion tests were performed according to the ISO-standard 10993-15:2000. Results: The increase in temperature of 18ºC induced an increase in the spring force of 30%. However, when the temperature returns to 37ºC the distraction force recovers near the initial level. After cooling down the spring to 15ºC, the force decreased by 46%. This investigation show as the temperature increase, the corrosion potential shifts towards negative values and the corrosion density is rising. Conclusions: The changes of the temperatures do not modify the superelastic behaviour of the NiTi closed-coil springs. The corrosion potential of NiTi in artificial saliva is decreasing by the rise of the temperatures.