Bone reactions around transplanted roots. A 5-month quantitative study in dogs

Area of Science:

• Oral surgery
• Periodontology
• Bone biology

Background:

• Root transplantation is a surgical procedure with potential applications in dentistry.
• Understanding endosteal bone reactions to transplanted roots is crucial for optimizing outcomes.
• The role of periodontal ligament (PDL) remnants in this process requires further investigation.

Purpose of the Study:

• To investigate endosteal bone reactions surrounding transplanted roots.
• To determine the influence of preserving periodontal ligament (PDL) remnants on bone healing and adaptation.
• To compare bone reactions between roots with preserved PDL and those with damaged PDL.

Main Methods:

• 20 roots from premolars were transplanted into prepared edentulous bone cavities in 5 dogs.
• One group of roots had their PDL remnants preserved; the other group had PDL removed.
• Bone reactions were analyzed after 5 months, focusing on bone volume, adipocyte content, osteoclast number, and bone remodeling activities.

Main Results:

• Preserved PDL groups showed higher bone volume in proximal compared to distal areas.
• Bone maturation (adipocyte content) was less pronounced in proximal areas of preserved PDL groups.
• Increased osteoclast numbers and bone remodeling activities were observed in proximal zones of preserved PDL groups.
• Transplantation of PDL-damaged roots did not stimulate similar bone rearrangement, leading to an edentulous crest structure.

Conclusions:

• The organization of PDL around transplanted roots is linked to bone tissue rearrangement, suggesting an adaptive response to mechanical strain.
• PDL preservation is critical for initiating bone remodeling and adaptation around transplanted roots.
• PDL damage negates these adaptive bone responses, resulting in a non-receptive bone environment.