Preventive effect of doxycycline sponge against bisphosphonate-related osteonecrosis of the jaws: an animal study

The aim of this study is to investigate the effect of doxycycline collagen sponge on bisphosphonate-related osteonecrosis of the jaw (BRONJ) and the level of serum biomarkers as an indicator of osteonecrosis. Twenty-four rats were divided into four groups. Animals in the control group were injected with saline and animals in Groups I, II and III were injected with zoledronate three times a week for eight weeks. After eight weeks, the following procedures were performed in each group. In Group I: extraction of maxillary first molar, in Group II: extraction of maxillary first molar and mucoperiosteal coverage was performed and in Group III: extraction of maxillary first molar and mucoperiosteal coverage with doxycycline collagen sponges was performed. At the end of 16 weeks, all animals were sacrificed. Serum collagen type I C-telopeptide (CTx), tartrate-resistant acid phosphatase (TRACP 5b) and alkaline phosphatase (ALP) levels’ analysis, clinical examination, histological and histomorphometrical analysis were performed. As a result no significant difference in CTx, TRACP 5b and ALP levels was observed between groups. Complete mucosal healing was observed in all animals in the control group and 66.7% of animals in Group III. The necrotic bone area in Group III was significantly lower than the other groups (p < 0.01). Statistically significant difference was observed between groups in terms of detached osteoclast number (p < 0.01). In conclusion, local application of doxycycline could have a positive effect in reducing the risk of BRONJ in rats