[Effect of zoledronic acid on mandibular socket healing process of mice at an early stage].

Purpose: To investigate how bisphosphonates affect early process of socket healing in mice model.

Methods: Eighteen 8-9 weeks C57BL/6 male mice were randomly divided into control and experimental group. Bisphosphonate-related osteonecrosis of the jaw（BRONJ）model was conducted by intraperitoneal injection of zoledronate（ZOL） and extraction of lower left first molar in mice. Three, five, seven day after surgery, the mice were sacrificed and paraffin-embedded slides were made. H-E staining was used to evaluate the gross condition. The distribution and amounts of osteoclasts were measured by TRAP staining. Finally, immunochemical staining was used to detect RUNX2 and CTSK level. All experiments were duplicated thrice, ImageJ was used for transformation of pictures and SPSS 20.0 software package was used for statistical analysis.

Results: In comparison with the control group, early process of socket healing in the experimental group was generally delayed. RUNX2,CTSK,TRAP expression level was decreased. On the whole, early bone remodeling process in ZOL injection group was suppressed.

Conclusions: Zoledronic acid inhibited the migration of fibroblasts into socket, and reduced the expression of Runx2, hindering new bone formation. It also can reduce the expression of TRAP 3，5，7 days after tooth extraction and CTSK expression three days after operation, thus inhibiting the bone resorption function of osteoclasts.