Present bone transplantation includes autogenous bone graft, allogenic bone transplantation, and artificial bone implant.
  Whereas autogenous bone graft is the major treatment, it is accompanied by several problems such as high invasiveness, limited quantity of bone and poor postoperative sensuousness.
　Allogenic bone transplantation, which is performed in the United States, is hardly performed in Japan because of risk of infection or an ethical viewpoint.
　Existing bone implants are not satisfactory in biodegradation, shape or handling.
　Also, existing surgical techniques require surgeons to collect bone from the donor site and manually carve it to fit to the defect, and it is highly invasive and often accompanied by postoperative pain.
　Then, we are promoting the development of "custom-made bone implant with geometry that precisely fits to bone defects and inner structures for enhancing bone regeneration"