Peri-implant bone organization under immediate loading state. Circularly polarized light analyses: a minipig study

Area of Science:

• Dental Implantology
• Biomaterials Science
• Bone Biology

Background:

• Immediate loading of dental implants is a key research area in implant dentistry.
• While osseointegration is achievable with stable, microstructured implants, data on peri-implant bone remodeling is limited.

Purpose of the Study:

• To investigate bone formation and remodeling around immediately loaded versus unloaded dental implants.
• To identify key parameters influencing implant success in an immediate loading protocol.

Main Methods:

• Placement of 85 immediately loaded and unloaded microstructured implants in minipig mandibles and maxillae.
• A 4-month healing period followed by histomorphometric analysis using light microscopy and specialized software.
• Evaluation of collagen fiber orientation and osteon formation in peri-implant bone.

Main Results:

• Implants achieved osseointegration with an average insertion torque >35 Ncm; lower torque resulted in implant loss.
• Bridge insertion torque (BIT), localization (mandible/maxilla), and implant insertion torque (IIT) were significant success predictors.
• Immediately loaded implants showed more transversely oriented collagen fibers and higher secondary osteon quantities.

Conclusions:

• Immediately loaded implants exhibit superior bone formation and remodeling compared to unloaded implants after 4 months.
• Transversely oriented collagen fibers are prevalent in peri-implant bone around loaded implants.
• An average insertion torque >35 Ncm is crucial for successful immediate implant loading.