Bone healing pattern in surgically created circumferential defects around submerged implants: an experimental study...

Area of Science:

• Dental Implantology
• Bone Regeneration
• Periodontology

Background:

• Marginal bone defects around dental implants can compromise long-term success.
• Understanding the healing dynamics of these defects is crucial for optimizing treatment outcomes.

Purpose of the Study:

• To investigate the histomorphometric healing of marginal bone defects of varying sizes around submerged titanium implants.
• To compare the bone regeneration process in small (0.5 mm) versus large (1.25 mm) marginal defects in a canine model.

Main Methods:

• Mandibular premolars and molars were extracted in 12 dogs, followed by flap elevation and implant placement creating controlled marginal defects.
• Defects were categorized as small (0.5 mm) or large (1.25 mm) based on the initial gap between the implant and bone.
• Biopsies were collected at 5, 10, 20, and 30 days post-surgery for histomorphometric analysis of bone formation.

Main Results:

• Bone formation initiated from the defect base and lateral walls in both small and large defects.
• A greater volume of new bone was observed in larger defects, with significant formation occurring between days 10 and 20.
• After 30 days, the newly formed bone outline was equidistant from the implant surface in both defect types, and complete defect fill was not achieved.

Conclusions:

• Marginal defects around submerged implants regenerate through distance osteogenesis within 20-30 days.
• While bone regeneration occurs, complete defect fill is not achieved within one month post-surgery.
• The study provides insights into the timing and extent of bone healing in peri-implant defects.