[Relaxation of an elastomeric chain under constant elongation].

A modality of elastomeric chain, Power Chain II (Ormco Co) was studied in vitro in order to observe the behavior of the force it exerts under constant elongation. Eight groups of ten samples each of the elastomeric material were placed at two different distances, 25 and 35 mm, and then proceeded to measure their magnitude at different time intervals (initial force, after 24 hours, a week and a month) under four varying conditions: cut in three and four links, pre-elongated and not pre-elongated. All specimens were immersed in saline water at a constant 37 degrees C (98.6 degrees F). Relaxation of the force observed after 24 hours was, for all groups, 52.85%, similar to that found in other studies. Although decrease of residual force was lower in the pre-elongated groups, larger residual magnitude was observed in the non pre-elongated groups.