The use of a neodymium-iron-boron magnet device for positioning a multi-stranded wire retainer in lingual retention--a pilot study in humans

Abstract

The aim of this study was to evaluate the time requirement of a newly developed device made of neodymium-iron-boron (NdFeB) magnets for positioning a multi-stranded, canine-to-canine retainer during bonding compared with dental floss and a transfer tray. Forty-five patients aged between 12 and 33 years (26 male, 19 female) previously treated with fixed appliances were enrolled in the study. The patients were randomly allocated to three groups (15 per group). For each group a mandibular canine-to-canine retainer of 0.018 inch Dentaflex multi-stranded wire (Dentaurum) was prefabricated for each patient on a cast. The bonding procedure was identical, except for the method of positioning the wire during adhesive fixation: group A dental floss, group B a small prefabricated transfer tray of dental resin and group C the NdFeB magnet device. For each group, the time required for the complete bonding process was measured. Kruskal-Wallis and Wilcoxon-Mann-Whitney tests were used for group and pairwise comparisons, respectively. The three methods required statistically significant different times (P < 0.001). The Wilcoxon-Mann-Whitney test revealed that wire positioning with the magnet device was significantly faster [4.98 minutes; standard deviation (SD) 0.68 minutes] than with dental floss (7.65 minutes, SD 1.14 minutes; P = 0.0001) or with transfer tray (5.75 minutes, SD 0.57 minutes; P = 0.001). The NdFeB magnet device is a timesaving appliance for positioning a multi-stranded, canine-to-canine retainer during bonding when compared with dental floss and an individually prefabricated transfer tray.

Accuracy of fit of 3-to-3 retainers after adhesive fixation using a neodymium–iron–boron magnet chain

“…In a clinical study with 45 patients [8], the investigators demonstrated that retainers were significantly more rapidly fixed with the magnet chain than with dental floss or with a custommade resin-positioning aid as used in this study. As the time for adhesive fixation is reduced, there is less probability that the etched enamel surface will be contaminated with saliva, sulcus fluid, or blood, possibly increasing the retainer stability [1,6].…”

“…The slightly better fit only indicates that the lack of positioning with the magnet chain is ultimately not a problem and that the aforementioned clinical advantages [8] are not accompanied by inferior fit. The magnet chain method is also generally less expensive, as it dispenses with various laboratory steps necessary to make a positioning aid.…”

“…In einer klinischen Studie an 45 Patienten [8] konnte gezeigt werden, dass die Retainer mithilfe der Magnetkette signifikant schneller befestigt werden als unter Verwendung von Zahnseide bzw. einer individuell angefertigten Positionierhilfe aus Kunststoff, wie sie auch in der vorliegenden Studie verwendet wurde.…”

“…Die leicht bessere Passung hat lediglich gezeigt, dass die fehlende Positionierung bei Verwendung der Magnetkette letztendlich kein Problem darstellt und die zuvor beschriebenen klinischen Vorteile [8] nicht mit einer geringeren Passung einhergehen. Insgesamt ist bei Verwendung der Magnetkette auch mit geringeren Kosten zu rechnen, da verschiedene Laborschritte zur Anfertigung einer Übertragungs-hilfe entfallen.…”

Sabi̇t Li̇ngual Retai̇ner Yapiminda Kullanilan Materyaller Ve Uygulama Yöntemleri̇

“…Büküm işlemi model üzerinde gerçekleştirilen retainerlar hasta ağzına uyumlanırken dişler üzerinde pasif olarak sabit kalabilmesi için kullanılan farklı yön-temler mevcuttur. Bunlar [45][46][47][48][49][50][51][52][53] (Resim 2); parmak yardımı ile sabit tutmak, dental floss, elastik ligatürler, ligatür telleri ile sabitlemek, ortodontik mumların kullanımı, springlerin kullanımı ile sabitleme, ortodontik elastik zincir, ortodontik separatörler ile sabitleme, magnetler kullanılarak sabitleme, ağız içine taşıyıcı ajanlar(heavy body...) dır.…”