Orthodontic load on short maxillary implants with reduced sink depth: an experimental study.

Area of Science:

• Orthodontics
• Dental Implantology
• Biomaterials

Background:

• Temporary anchorage devices (TADs) are crucial for orthodontic tooth movement.
• Optimizing TAD design, including length and insertion depth, is essential for predictable outcomes.
• Reduced sink depth in TADs may offer advantages in specific clinical situations.

Purpose of the Study:

• To experimentally evaluate the positional stability and histomorphometric characteristics of length-reduced TADs (Orthosystem, 4 mm) with reduced insertion depth.
• To assess the efficacy of these TADs under long-term orthodontic loading.

Main Methods:

• Four foxhounds received maxillary premolar extractions followed by a healing period.
• Length-reduced TADs were inserted into edentulous areas and the mid-palatal region, intentionally submerged.
• Implants were subjected to orthodontic loading (approx. 2 N) for 24 weeks, with some serving as controls.

Main Results:

• Clinical and histological assessments confirmed positional stability of the loaded TADs.
• Mean bone contact percentages were 71.3% (alveolar control), 79.6% (alveolar test), and 72.2% (palatal test).
• Implants were inserted at depths of 3.2 mm (ACI), 3.3 mm (ATI), and 2.6 mm (PTI).

Conclusions:

• A minimum of 3 mm of intrabony implant length appears sufficient for positional stability during prolonged orthodontic loading.
• High bone-to-implant contact percentage likely contributes to the stability of these reduced-length TADs.
• Length-reduced TADs with reduced sink depth demonstrate promising potential for orthodontic anchorage.