Dimensions Define Stability: Insertion Torque of Orthodontic Mini-Implants: A Comparative In Vitro Study.

Area of Science:

• Orthodontics
• Biomaterials Engineering
• Dental Implantology

Background:

• Orthodontic mini-implants offer reliable anchorage, overcoming challenges in treatment.
• This study investigates insertion torque (IT) variations among different mini-implant types.
• The null hypothesis posited no significant IT difference based on mini-implant type.

Purpose of the Study:

• To compare the insertion torque (IT) values of three types of orthodontic mini-implants.
• To evaluate the influence of mini-implant dimensions on insertion torque.
• To determine the clinical implications of IT variations for implant stability.

Main Methods:

• In vitro analysis of 12 mini-implants with varying lengths (6-12 mm) and diameters (1.4-2.0 mm).
• Insertion at a 90° angle into artificial bone (Sawbones®) without pre-drilling.
• Statistical analysis using ANOVA, Tukey's post hoc test, and Spearman's correlation.

Main Results:

• Significant differences in IT were observed among mini-implants (p = 0.035).
• Insertion torque correlated positively with diameter (ρ = 0.609, p = 0.047) and length (ρ = 0.890, p < 0.001).
• Lomas Mondefit® (2 × 8 mm) exhibited the highest IT (35 N), while Jeil (2 × 12 mm) had the lowest.

Conclusions:

• Mini-implant diameter and length are significant determinants of insertion torque.
• These dimensional factors are critical for achieving optimal stability and performance in clinical orthodontic applications.
• Understanding IT variations aids in selecting appropriate mini-implants for predictable anchorage.