99MTc-diphosphonate bone imaging and uptake in healing rat extraction sockets.

Clinically positive bone scans of the jaws may result from a variety of benign dental conditions. An experimental system for studying radionuclide imaging and uptake in the jaws of rats was developed. Sequential 99mTc-diphosphonate bone scans and radionuclide uptake determinations were performed on rats after standardized extractions of their mandibular left first molars. Positive bone scans were seen 4-16 days after molar extraction, and increased radionuclide uptake was found in the healing extraction wounds 4-42 days after the extraction. Conventional radiography and histology fail to show unusual bony architecture in extraction sockets at such times. These results correlate with clinical findings in patients and suggest that human beings may have positive bone scans for several months after dental extraction.