Purpose Analysis of the influence of geranyl-geraniol (GG) addition on four bisphosphonate derivatives regarding their influence on cell viability and migration ability of bone metabolism and endothelial cells in vitro. Methods Clodronate, pamidronate, ibandronate, and zoledronate were observed with and without GG addition, for their effect on human osteoblasts (HOB), normal human dermal fibroblasts (NHDF), human endothelial progenitor cells (EPC), and endothelial cells of the human umbilical cord (HUVEC) using migration-, MTT-, and colony-forming cell assays. Results Data pointed to a depressing effect of all bisphosphonates on the migration ability of NHDF, EPC, and HOB. MTT assay demonstrated a decreased cell viability of HUVEC of all bisphosphonates in a 50 μM concentration and of NHDF when treated with 50 μM of clodronate, ibandronate, or zoledronate. Tested drugs showed a depressing effect on colony-forming potential of EPC even in a 5 μM concentration. GG addition demonstrated an attenuate impact on bisphosphonate effect on all primary cell cultures, respectively. Conclusion In vitro comparison showed that the addition of GG weakens the effect of all bisphosphonates examined. It supports investigations that suggest GG to be able to prevent bisphosphonate-associated osteonecrosis of the jaw (BP-ONJ) in vivo. Future clinical trials may discover the local therapeutic use of GG for the prevention of BP-ONJ.

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Purpose The objective of this study was to demonstrate the suitability of cone-beam computed tomography (CBCT) for in vivo research in periodontology, with implications for oral implantology, facial traumatology, and all disciplines involved in treating patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ). Methods Halves of the jaws of 9 Swiss mountain sheep, assigned to a control group (n=3), an osteoporosis group (n=3) and a zoledronate-exposed group (n=3), were examined. Clinical and radiological evaluations were conducted using CBCT imaging to assess whether periodontitis and bone defects were observed to a significant extent after surgical tooth extraction. Results In contrast to the control and osteoporosis groups, the zoledronate group exhibited significant residual bone defects following tooth extraction ( P <0.05). CBCT more objectively revealed these effects and enabled a numerical evaluation (in mm 3 ). Conclusions Evaluating residual defects in bone blocks from sheep using CBCT analysis was found to be as effective as a clinical examination conducted by specialists in oral and maxillofacial surgery. The strong correlation between radiological findings and clinical conditions suggests that CBCT may become increasingly important in the future, particularly in periodontological research related to BRONJ.