Bone healing at non-submerged implants installed with different insertion torques: a split-mouth histomorphometric...

Area of Science:

• Biomaterials science
• Dental implantology
• Histomorphometry

Background:

• Dental implant stability is crucial for osseointegration.
• Insertion torque is a key factor influencing primary implant stability.
• Understanding the impact of varying insertion torques on bone healing is essential for clinical success.

Purpose of the Study:

• To histomorphometrically evaluate and compare bone healing around dental implants placed at standard (~30 Ncm) versus very low (<10 Ncm) insertion torque values.
• To assess the new bone formation and bone density in relation to implant surface at different torque levels.
• To determine if very low insertion torque compromises implant osseointegration.

Main Methods:

• Twelve patients received two screw-shaped titanium implants in the mandible, one at <10 Ncm and one at ~30 Ncm insertion torque.
• Implants were allowed to heal in a non-submerged manner for 8 weeks.
• Histological analysis of retrieved biopsies was performed to quantify new bone contact and density.

Main Results:

• New bone in contact with the implant surface was 39.3% at <10 Ncm and 49.4% at ~30 Ncm.
• Total mineralized bone was 46.8% at <10 Ncm and 57.0% at ~30 Ncm.
• No statistically significant differences were found in new bone or total mineralized bone density between the two groups.

Conclusions:

• A trend towards higher osseointegration was observed with ~30 Ncm insertion torque compared to <10 Ncm.
• Implants placed with very low insertion torque (<10 Ncm) can achieve successful osseointegration.
• Clinical outcomes suggest that achieving good implant integration is possible even with minimal initial torque.