Physical and mechanical properties of elastomers in orthodontic positioners

Influence of material choice on the force delivery of bimaxillary tooth positioners on canine malpositions

“…In comparison with conventional retainers, more tooth contacts were reported with the positioner after 3 months of wear [22]. However, another report found no significant improvement in tooth contact through positioner wear [21].…”

“…The original tooth positioner was made of natural rubber [8], which was replaced by a variety of materials including thermoelastic acryl, polyether urethane, ethylene vinyl acetate, and silicone [3,11,21]. The tooth positioner was developed in 1945 to provide "a simple appliance that would influence all of the teeth to flow into their best possible position" [8].…”

“…The tipping of teeth within reasonable limits of 1-2 mm is frequently described as the most relevant tooth movement during positioner therapy [3,6,10,21]. Rotational correction is advantageous in incisors but difficult in all other teeth [4].…”

“…Rotational correction is advantageous in incisors but difficult in all other teeth [4]. Finally, extrusive and intrusive movements are believed to be unpredictable [6,21]. In addition to moving individual teeth, the positioner has also been advocated for improving the centric condylar position.…”

“…Der ursprüngliche Zahnpositioner bestand aus Naturgummi [8], das durch eine Vielzahl von Materialien einschließlich thermoelastisches Acryl, Polyetherurethan, Ethylenvinyl-Acetat und Silikon ersetzt wurde [3,11,21]. Die Entwicklung des Zahnpositioners im Jahre 1945 war von der Absicht getragen, "eine einfache Apparatur zu finden, die so auf alle Zähne einwirken würde, dass sie sich fließend in ihre bestmögliche Position bewegen" [8].…”