Comparison of the forces generated by steel, nickel titanium and elastomeric separators

Abstract EN

Background: This study compared stainless steel spring, NiTi spring, and elastomeric ring separators for their initial force of separation and after a tooth separation of up to 0.8mm.

Materials and Methods: The five types of separators used were TP spring, Truflex springs, NiTi springs (Ortho Technology), Dentalastics (Dentaurum), Alastik (3M Unitek) separators.

The testing apparatus consisted of a framework holding two acrylic teeth in contact; the upper tooth attached to a calibrated micrometer that controls the amount of separation between the teeth by fractions of a millimeter and the lower tooth attached to an electronic balance that registers the force of separation after inserting a separator between the two teeth.

After registering the initial force of separation, the micrometer was adjusted so that the contact area was opened up to 0.8mm in increments of 0.1mm and the separating force was measured.

Results: Dentalastics exerted the highest force levels and NiTi springs showed the lowest force values; while Alastik, Truflex and TP separators were in the middle.

When the teeth where separated incrementally 0.1mm at a time, Truflex and NiTi springs showed a gradual drop in the separation force, both elastomeric separators showed a steep drop from their high initial forces to a relatively high remaining force at 0.8mm separation, while TP springs gave the steepest drop that fell below 50 grams at 0.3-0.5mm separation.

Conclusions: Truflex springs gave moderate initial separation forces that remained effective even at 0.8mm separation.

Keywords: NiTi separators, TP springs, elastomeric separators.

(J Bagh Coll Dentistry 2008; 20(1):78-86).