Pérdida de fuerza de los elásticos de uso intraoral en ortodoncia

Resumo

lntroduction: The purpose of this study was to evaluate the force degradation of orthodontic elastics. Methods: Open and closed chains from three orthodontic suppliers: Rocky Mountain Orthodontic, Ormco and GAC, were tested. Thirty 5cm length samples of each chain were stretched to three times their original length and were stored in artificial saliva at 37ºC. The force delivery of each chain was measured using a dynamometer after 0, 1, 12, 24 hours, 2, 3, 4, 5, 6, 7, 14, 21 and 28 days. Results: Statistically significant differences in levels of force between the different chains were observed. lnitial forces varied between 427.0 grs. to 644.0 grs. The greatest force loss occurred within the first 24 hours: however, during the following 2 days forces continued to fall but at a slower rate. After 28 days, the force values ranged between 42.5% -59.3% in comparison to the initial force, and the chains from all suppliers delivered forces greater than 215 grs. Conclusions: The initial force produced by elastomeric chains was very high. The force produced after 4 weeks was still conducive to dental movement.