Affiliations: ITIS d. o. o. Ljubljana, Center for Implantable Technology and Sensors, University of Ljubljana, Ljubljana, Republic of Slovenia | Faculty of Natural Sciences and Engineering, Department of Materials and Metallurgy, Ljubljana, Republic of Slovenia | Faculty of Medicine, Department of Orthodontics, Ljubljana, Republic of Slovenia
Note: [] Address for correspondence: Polona Pečlin, MD, ITIS d. o. o. Ljubljana, Center for Implantable Technology and Sensors, Lepi pot 11, 1102 Ljubljana, Republic of Slovenia. Tel.: +386 4155 7252; Fax: +386 1470 1939; E-mail: polonapeclin@ gmail.com.
Abstract: The purpose of this investigation was to assess mechanical properties of Superelastic Retraction Coil Springs for orthodontic use. To reach a goal, a test frame, comprising measuring force transducers was developed. To perform metallographic analyses of the nickel–titanium wire the samples of Superelastic Retraction Coil Springs were observed by scanning electron microscope. For in vivo testing, twenty male Wistar rats, 11–12 weeks of age, were used (Group I with Superelastic Retraction Coil Springs, Group II controls). To simulate human distraction as close as possible, all the applied Superelastic Retraction Coil Springs were modified. The Superelastic Retraction Coil Springs creating a constant force of 25 cN were then attached between the upper left first molars and upper left incisors. Results showed that the reproducible force of 25 cN was shown over a range of 1–11 mm extension. Results also showed that the distance between aforementioned teeth, measured on days 0, 7, 14, 21, 24, 32, 37 and 40, decreased in Group I. Contrary, in Group II the distance between the teeth increased during the study (p<0.001).
Keywords: Distraction osteogenesis, in vivo testing, metallographic analysis, shape memory alloys, Superelastic Retraction Coil Springs
