Abnahme der Haltekraft elastischer Ligaturen in vivo

Zusammenfassung

Im Mittelpunkt der vorliegenden In-vivo-Studie stand die Untersuchung der Kraftabnahme elastischer Ligaturen über einen Zeitraum von 4 Wochen.

Bei 10 Patienten, die sich am Ende der Nivellierungsphase befanden, wurden elastische Ligaturen angebracht und an den Tagen 0, 7, 14, 21 und 28 Messungen durchgeführt. Mit einer Messapparatur wurde die Abzugskraft ermittelt, die notwendig war, um den 0,018″×0,025″ CuNiTi-Bogen 2 mm lotrecht zur Zahnoberfläche aus dem Bracketslot auszulenken. Die dazu nötige Kraft wurde hinsichtlich Messzeitpunkt, Kiefer (Oberkiefer/Unterkiefer) und Zahntyp (Incisivus/Caninus/Prämolar) analysiert.

Die Abnahme der Haltekraft zwischen allen erhobenen Messzeitpunkten war höchst signifikant. Die größte Kraftabnahme wurde innerhalb der ersten Woche verzeichnet (197,161 cN). Die Haltekraft reduzierte sich nach 4 Wochen um 46,96%. Kein signifikanter Unterschied konnte zwischen den Abzugswerten in Ober- und Unterkiefer ermittelt werden. In der Incisivi-Region wurden signifikant höhere Abzugskräfte ermittelt als in der Prämolaren-Region.

Abstract

The main purpose of this in vivo study was the examination of the relaxation of elastomeric ligatures during a period of 4 weeks.

10 patients were fitted with elastic ligatures, and measurements were taken on days 0, 7, 14, 21 and 28. A measuring apparatus quantified the necessary force to pull a 0.018″×0.025″ CuNiTi archwire 2 mm from the brack slot perpendicularly to the tooth surface. The required force was evaluated regarding time of measurement, jaw (upper/lower) and type of tooth (anterior tooth/canine/premolar).

The results did show highly significant differences in the reduction of holding force between all points of time. The greatest reduction of force was oberserved within the first week (197.161 cN). The holding force was decreased by 46.96% over 4 weeks. No significant difference could be registered between the holding forces of the elastic ligatures in the upper and lower jaw. Significantly higher holding forces were measured in the incisor region than in the premolar region.

Schlüselwörter

elastische Ligaturen - Haltekraft

Key words

elastomeric ligatures - holding force

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