Influence of initial strain on the force decay of currently available elastic chains over time.

Objective: To investigate the dependence of force decay on the initial strain applied to currently available elastic chains.

Materials And Methods: Eight different elastic chains from eight major companies were tested for force decay over a period of 3 weeks at 50% and 100% strain. They were stored in water and thermocycled between 5°C and 55°C.

Force levels of 23 nickel-titanium open-coil springs in compression testing.

Introduction: Open-coil springs are commonly used auxiliaries in fixed orthodontic appliance therapy. Space opening for impacted or heavily crowded teeth as well as distalization of molars all require specific force levels. It is the aim of the current study to present an overview of the mechanical properties of currently available nickel titanium (NiTi) closed coil springs.

Influence of bending mode on the mechanical properties of nickel-titanium archwires and correlation to differential scanning calorimetry measurements.

Introduction: Nickel-titanium orthodontic archwires are used with bonded appliances for initial leveling. However, precise bending of these archwires is difficult and can lead to changes within the crystal structure of the alloy, thus changing the mechanical properties unpredictably. The aim of this study was to evaluate different bending methods in relation to the subsequent mechanical characteristics of the alloy.

Active and passive self-ligation-a myth?

Objective: To compare the frictional behavior of several self-ligating brackets with that of normal brackets both with and without tipping force-moments and in combination with different archwire dimensions.

Materials And Methods: The resistance to sliding (RS) of seven self-ligating brackets, a conventional bracket, and a ceramic bracket with a low-friction clip were evaluated in combination with three different archwires and tipping force-moments of 0 and 10 Nmm. The center of rotation for the measurements was set within the center of the bracket or with a 10-mm offset.

Load-deflection characteristics of superelastic nickel-titanium wires.

Objective: To determine the mechanical properties of commercially available thermodynamic wires and to classify these wires mathematically into different groups.

Materials And Methods: The samples examined were 48 nickel-titanium (NiTi) alloy orthodontic wires commercially available from five manufacturers. These samples included 0.