Jiahui Li
| Jiahui Li |
Jiahui Li,Su Lee
Hyeran H. Jeon
Orthodontics, University of Pennsylvania, School of Dental Medicine
Introduction
Since Dr. Branemark introduced the concept of osseointegration with titanium implants in 1965, dental implants have become one of the most common solutions to replace missing teeth and provide bony anchorage to support dental prostheses. Orthodontic mini-implants, the temporary anchorage devices (TADs), are first used clinically by Drs. Creekmore and Eklund in 1983 to provide skeletal anchorage for orthodontic tooth movement. Although the evolution of orthodontic mini-implants is largely based on conventional implants, there is not yet a comprehensive comparison between the two types of implants. The aim of this review paper is to compare conventional implants and mini-implants in their structural features, histological and biomechanical considerations, factors affecting the success rates, including bicortical engagement, and possible complications.
Methods
A thorough literature search was performed in the PubMed and Google Scholar databases for papers published in English from 1983-2021 with keywords “dental implants” or “orthodontic mini-implants”, “TADs” (temporary anchorage devices), “orthodontic miniscrews” and corresponding areas of interest. Other sources include references of the selected papers. Results were sifted and reviewed carefully.
Results
The gold standard of conventional implants material is titanium with surface modifications such as sandblasting or acid etching to enhance osseointegration, while the orthodontic mini-implants can be made of titanium or stainless steel with machined or surface-treated forms. The stability of conventional implants and orthodontic mini-implants can be assessed with insertion torque, Resonance Frequency Analysis, PerioTest Value, and Implant Stability Quotient. However, the orthodontic mini-implants show lower values in all parameters except for PerioTest Value, in which higher values indicate a looser implant. Albeit the differences, conventional implants and mini-implants share similar success-related factors such as implant design, location, and placement technique. Tapered design, longer length, and placement in sites with higher bone density and thicker cortical bone show higher stability in both implants. Both show better primary stability with bicortical engagement compared with monocortical engagement.
Conclusion
Conventional implants and orthodontic mini-implants have similar success-related factors and paths of evolution. Thus it is beneficial to consider recent modifications to conventional implants as the directions to improve orthodontic mini-implants.