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Machine-driven versus manual insertion mode: influence on primary stability of orthodontic mini-implants
Domen Novsak1, Magda Trinajstic Zrinski, Stjepan Spalj
1*Intern, Public Health Center Rijeka, Rijeka, Croatia. †Research Assistant, Department of Orthodontics, School of Medicine, University of Rijeka, Rijeka, Croatia. ‡Assistant Professor, Department of Orthodontics, School of Medicine, University of Rijeka, Rijeka, Croatia.
Manual insertion of orthodontic mini-implants provides better primary stability. Thicker cortical bone and larger implant diameter are key predictors of stability, outweighing insertion method.
Area of Science:
- Orthodontics
- Biomaterials Engineering
- Dental Implantology
Background:
- Primary stability is crucial for orthodontic mini-implant success.
- Insertion torque is a key indicator of primary stability.
- Factors influencing insertion torque require further investigation.
Purpose of the Study:
- To evaluate the impact of insertion method on maximal insertion torque.
- To assess primary stability of orthodontic mini-implants.
- To control for variables like cortical bone thickness, mini-implant dimensions, and insertion forces.
Main Methods:
- Six types of mini-implants with varying diameters (1.4-2.0 mm) and lengths (6-8 mm) were used.
- Implants were inserted manually and mechanically into pig rib bone samples (n=120).
- Cortical bone thickness, insertion torque, and vertical forces were meticulously measured.
Main Results:
- Thicker cortical bone (24.2%) and wider implant diameter (20.6%) were the strongest predictors of primary stability.
- Manual insertion (9.9%) also contributed to better primary stability.
- Maximal vertical insertion force and lower vertical force at maximal torque showed minor contributions.
Conclusions:
- Manual insertion of orthodontic mini-implants yields superior primary stability compared to mechanical methods.
- Cortical bone thickness and implant diameter are more significant determinants of primary stability.
- Findings inform optimal selection and placement of orthodontic mini-implants for enhanced stability.
