**Results and discussion**

The biopsy tissue showed that DDM granules were received to host and the biological width (4-6mm) was acquired. The DDM residues were partially observed during the implant placement. Bone biopsy revealed the DDM were remodeled by bone at 4 months. This patient was successfully restored with the dental implants after the DDM autograft (Fig. 6d). Though animal-derived atelocollagens have been generally used as medical materials, autogenous decalcified dentin is a highly insoluble collagenous matrix and a safe biomaterial.

### **Conclusion**

Human DDM granules from vital teeth are collagenous matrics with osteoinductive potency, and the human dentin can be recycled as autogenous biomaterials for local bone engineering.

Case 1 and 2 were approved by the Ethical Committee in the Health Sciences University of Hokkaido. All subjects enrolled in this research have responded to an Informed Consent which has been approved by my Institutional Committee on Human Research and that this protocol has been found acceptable by them.

a: 4 missing teeth and atrophied upper maxilla b: DDM autograft before suture c: just after operation d: final view after prosthetic restoration using dental implantation

Fig. 6. Case 2: Bone regeneration, 58 year-old woman
