2026-04-17T01:00:27Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/212372026-02-05T02:32:54Zcom_2072_1033col_2072_452950

urn:hdl:2117/21237 Effect of temperature on the orthodontic clinical applications of NiTi closed-coil springs Espinar, Eduardo Llamas Carreras, Jose Maria Barrera Mora, Jose Maria Ábalos, C. Gil Mur, Francisco Javier Àrees temàtiques de la UPC::Enginyeria dels materials Nickel-titanium alloys Orthodontics Coils NiTi Orthodontic Recovery Springs Superelasticity Temperature Níquel-titani -- Aliatges Ortodòncia 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 D esign: 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 18 o C induced an increase in the spring force of 30%. However, when the temperature returns to 37 o C the distraction force recovers near the initial level. After cooling down the spring to 15 o C, 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. Peer Reviewed Postprint (published version) 2013-07-01 Article http://creativecommons.org/licenses/by-nc-nd/3.0/es/ Restricted access - publisher's policy Attribution-NonCommercial-NoDerivs 3.0 Spain