Medication-related osteonecrosis of the jaw (MRONJ) often develops after extraction of a tooth with a local infection. Therefore, it is necessary to develop extraction methods that can prevent MRONJ. Before examining whether antibiotics and atelocollagen administered in the extraction socket can prevent the development of MRONJ after tooth extraction, this study was conducted to determine the appropriate antibiotics concentration and to conduct a clinical study with a small number of cases as a preliminary study.

First, a mixture of minocycline and atelocollagen at different concentrations was implanted into the bone cavity formed in the rabbit head, and the local minocycline concentration was measured after 24 and 48 h. Next, the incidences of MRONJ after tooth extraction in patients receiving high-dose antiresorptive agents were compared between the atelocollagen and atelocollagen/minocycline mixture groups. A group that did not undergo transplantation was also compared as a historical control.

In animal studies, a mixture of 10 mg/ml minocycline injected into collagen and implanted into the bone cavity showed sufficiently high antimicrobial concentrations, even after 48 h. Post-extraction MRONJ occurred in 3 of the 13 control groups (23.1%), 3 of the 13 atelocollagen groups (23.1%), and 1 of the 13 atelocollagen/minocycline groups (7.7%).

Atelocollagen functions as a carrier for retaining antibiotics for a certain period. Although this was a study with a limited number of cases, it suggested that the local administration of atelocollagen/minocycline in the extraction socket may reduce the risk of MRONJ following tooth extraction.