Strain of bone-implant interface and insertion torque regarding different miniscrew thread designs using an...

Area of Science:

• Orthodontics and Dental Implantology
• Biomaterials Science
• Biomechanics

Background:

• Assessing the initial stability of orthodontic miniscrews is crucial for successful treatment outcomes.
• Dual-thread miniscrews are designed to improve anchorage, but their mechanical behavior requires thorough evaluation.
• Understanding the bone-implant interface strain and insertion torque is key to predicting stability.

Purpose of the Study:

• To compare the initial mechanical stability of dual-thread and single-thread self-drilling miniscrews.
• To analyze the strain at the bone-implant interface and insertion torque in artificial bone models with varying cortical thicknesses.

Main Methods:

• Insertion torque and strain measurements were recorded using a five-element strain gauge.
• The study utilized artificial bone models with cortical thicknesses of 1.0, 1.5, and 2.0 mm.
• Both single-thread (OAS-T1507) and dual-thread (MPlant-U3) miniscrews were implanted.

Main Results:

• Both miniscrew types exhibited strain exceeding 7790 μstrain across all tested cortical bone thicknesses.
• Dual-thread miniscrews showed significantly increased insertion torque with greater cortical bone thickness (P < 0.0001).
• Dual-thread miniscrews demonstrated significantly higher maximum insertion torque compared to single-thread types across all thicknesses (P < 0.0001).

Conclusions:

• Self-drilling dual-thread miniscrews provide superior initial mechanical stability.
• However, dual-thread miniscrews may induce strain exceeding physiological bone remodeling limits in thicker cortical bone.
• Careful consideration of cortical bone thickness is advised when using dual-thread miniscrews.