Evaluation of NiTi Superelastic Retraction Coil Springs for orthodontic tooth movement in rats.
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).
ITIS d. o. o. Ljubljana, Center for Implantable Technology and Sensors, University of Ljubljana, Ljubljana, Republic of Slovenia.
Janez
J
Rozman
Primož
P
Mrvar
Martina
M
Drevenšek
Polona
P
Pečlin
D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D001696:Biomechanical Phenomena; D019245:Compressive Strength / Q000502:physiology; D004548:Elasticity; D008297:Male; D008422:Materials Testing / Q000379:methods; D008954:Models, Biological; D009532:Nickel / Q000737:chemistry*; D009967:Orthodontic Appliances; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D013718:Tensile Strength / Q000502:physiology; D014025:Titanium / Q000737:chemistry*; D014087:Tooth Movement Techniques / Q000295:instrumentation*
D001672:Biocompatible Materials; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium