Comparison of stainless steel and titanium-molybdenum alloy closing loop archwires using numeric simulation model...

Area of Science:

• Orthodontics
• Biomaterials Science

Background:

• Orthodontic space closure is crucial for correcting malocclusions.
• Understanding the biomechanics of different archwire materials is essential for predictable treatment outcomes.

Purpose of the Study:

• To compare the moment-to-force (Mc/F) ratio and tooth movement types in anterior and posterior segments during orthodontic space closure.
• To evaluate the efficacy of stainless steel versus titanium-molybdenum alloy (TMA) loop archwires.

Main Methods:

• Utilized a 3D maxillary model with a first premolar extraction.
• Employed stainless steel brackets and 16x22-mil stainless steel and TMA closing loop archwires with specific gable bends.
• Performed repeated 1-mm activations to simulate orthodontic forces and analyzed Mc/F ratios and tooth movement.

Main Results:

• Both archwire types yielded an approximate Mc/F ratio of 5 mm in the anterior segment and 10 mm in the posterior segment.
• Anterior teeth exhibited controlled tipping, while posterior teeth demonstrated bodily movement, consistent with the Mc/F ratios observed.

Conclusions:

• Stainless steel and TMA closing loop archwires demonstrated comparable Mc/F ratios and produced similar types of tooth movement in both anterior and posterior segments.
• These findings suggest that both materials are effective for orthodontic space closure with predictable biomechanical responses.