In vitro frictional forces generated by three different ligation methods.

Journal: The Angle Orthodontist
Published:
Abstract

Objective: To test the hypothesis that there is no difference between the frictional forces produced by a passive self-ligating bracket (SLB) in vitro and a conventional bracket (CB) used with two types of elastomeric ligatures.

Methods: The brackets, wires and ligation methods used in vitro were a passive SLB and a CB used with two types of elastomeric ligatures (conventional elastomeric ligature [CEL] and unconventional elastomeric ligatures [UEL]). The bracket ligation systems were tested with two types of wires (0.014'' super elastic nickel titanium wire and 0.019'' x 0.025'' stainless steel wire). Resistance to sliding of the bracket/wire/ligature systems was measured with an experimental model mounted on the crosshead of an Instron testing machine with a 10 N load cell. Each sample was tested 10 consecutive times under a dry state.

Results: Frictional forces close to 0 g were recorded in all tests with SLB and in all tests with UEL on CB with both wire types. Resistance to sliding increased significantly (87-177 g) (P < .05) when CEL on CB was used with both wires.

Conclusions: UELs may represent a valid alternative to passive SLBs for low-friction biomechanics.

Authors
Paola Gandini, Linda Orsi, Chiara Bertoncini, Sarah Massironi, Lorenzo Franchi