Force reduction of orthodontic elastomeric chains after one month in the mouth.

The effect of ageing activated orthodontic elastomeric chains for one month in the mouth is reported. Over this period the mean value of exerted force fell by about 50 per cent of the original value. All the materials tested underwent a decrease in stiffness which contributed to a reduction in the force exerted. After a four week treatment period space closures in the range 0-5 mm were produced by the specimens tested.