A clinical comparison between nickel titanium springs and elastomeric chains.

Area of Science:

• Orthodontics
• Biomaterials Science
• Dental Mechanics

Background:

• Maxillary canine retraction is a critical phase in orthodontic treatment.
• Sliding edgewise mechanics are commonly employed for space closure.
• Comparing retraction forces and anchorage loss is essential for treatment efficiency.

Purpose of the Study:

• To compare the efficacy of nickel-titanium (NiTi) springs versus elastomeric chains in maxillary canine retraction.
• To evaluate molar anchorage loss associated with NiTi springs and elastomeric chains.
• To assess the impact of delivering a known force with sliding edgewise mechanics.

Main Methods:

• A split-mouth design was used with 12 patients requiring maxillary canine retraction.
• NiTi springs and elastomeric chains, delivering approximately 200g of force, were applied and reactivated every 28 days.
• Maxillary impressions were taken at 28-day intervals to measure space closure and molar movement.

Main Results:

• The mean rate of space closure with NiTi springs (1.85 mm/month) was marginally greater than with elastomeric chains (1.68 mm/month), with a statistically significant difference (p=0.011).
• Mean rates of molar anchorage loss were comparable: 0.46 mm/month for NiTi springs and 0.45 mm/month for elastomeric chains, with no statistically significant difference.
• Molar movement constituted one-quarter to one-third of space closure per month, despite the use of a transpalatal arch.

Conclusions:

• NiTi springs and elastomeric chains demonstrate similar rates of space closure and molar anchorage loss in maxillary canine retraction.
• Regular reactivation (every 28 days) is a key factor in achieving comparable outcomes with both retraction systems.
• The findings suggest that clinicians can achieve similar results regardless of the chosen appliance, provided consistent force delivery and reactivation schedules are maintained.