Force behaviour of elastic chains during a simulated gap closure in extraction therapy cases

Area of Science:

• Orthodontics
• Biomaterials Science

Background:

• Tooth movement relies on controlled forces from orthodontic appliances.
• Elastic chains are commonly used to apply continuous force for tooth alignment.
• Understanding the force characteristics of different elastic chain configurations is crucial for predictable treatment outcomes.

Purpose of the Study:

• To assess the force behavior of various elastic chains.
• To investigate the impact of different configurations and gap widths on chain forces.
• To determine optimal elastic chain setups for orthodontic tooth movement.

Main Methods:

• Utilized self-ligating brackets on aluminum plates simulating dental arches with varying gap widths (0.5-8.0 mm).
• Tested reset forces of open and closed elastic chains from four manufacturers in four distinct configurations.
• Measured forces using a universal testing machine and analyzed data statistically.

Main Results:

• Elastic chain configurations formed distinct subgroups regarding force output (P < .001).
• Configuration #4 exhibited significantly higher initial forces than configuration #3 (P = .029).
• Closed chains generated significantly higher initial forces than open chains (P = .029).

Conclusions:

• Intermediate rings adjacent to the gap do not significantly modulate force.
• Omitting a ring in the tooth gap can effectively modulate applied force.
• Open thermoset chains with an intra-gap ring (#3) are suitable for 4 mm gap closure.
• Open and closed thermoset chains (#4) are appropriate for residual gaps less than 2 mm.