Tapered orthodontic miniscrews induce bone-screw cohesion following immediate loading

Area of Science:

• Orthodontics
• Biomaterials Science
• Dental Implantology

Background:

• Orthodontic miniscrews provide anchorage during tooth movement.
• Assessing initial stability and the need for a healing period is crucial for successful treatment.
• Tapered designs may offer improved primary stability over straight designs.

Purpose of the Study:

• To evaluate the initial stability of tapered orthodontic miniscrews (T-type screws) versus straight orthodontic miniscrews (S-type screws).
• To determine the necessity of a healing period before applying orthodontic force.
• To assess the suitability of immediate loading for T-type screws.

Main Methods:

• Histological analysis of screw-to-bone contact in Wistar rats.
• Comparison of bone-screw contact ratio between T-type and S-type screws.
• Evaluation of immediate loading versus a healing period before force application.

Main Results:

• T-type screws demonstrated significantly higher bone-screw contact ratios (82.3%) compared to S-type screws (33.3%) in the immediate loading group.
• No significant difference in bone-screw contact ratio was observed between immediate loading and healing groups for T-type screws.
• Control group showed improved bone-screw contact over time with S-type screws (34.8% to 74.8%).

Conclusions:

• T-type orthodontic miniscrews exhibit excellent initial stability, allowing for immediate loading.
• A healing period is not necessary for T-type screws, simplifying orthodontic treatment protocols.
• T-type screws are a viable option for immediate orthodontic anchorage, enhancing treatment efficiency.