Kinetics of bone-resorbing activity in developing periapical lesions

Area of Science:

• Oral Biology
• Pathology
• Biomedical Research

Background:

• Periapical lesions involve bone destruction.
• The kinetics and source of bone-resorbing activity are not fully understood.

Purpose of the Study:

• To investigate the presence and kinetics of bone-resorbing activity in a rat periapical lesion model.
• To correlate this activity with lesion expansion phases.

Main Methods:

• A rat model was used to induce periapical lesions.
• Lesion size was measured using magnified radiographs and automated image analysis.
• Bone-resorbing activity was quantified by 45Ca release from fetal rat bones.

Main Results:

• Periapical lesions expanded most rapidly between days 0-15 (active phase) and slower thereafter (chronic phase).
• Significant bone-resorbing activity was detected in lesion extracts, peaking on days 10-15 and declining by day 30.
• Normal dental pulp and periodontal ligament showed no such activity.

Conclusions:

• Bone-resorbing activity is temporally associated with periapical bone destruction.
• The developed rat model is suitable for studying mediators of inflammatory bone resorption.