**3. Clinical study of human dentin**

#### **3.1. Case 1: Bone augmentation, 17 year-old female**

**Patient:** A 17-year-old female presented with missing teeth (#11). Clinical and radiological examinations revealed atrophied bone and fractured root residue in the region (Fig. 3a,b). Her medical history was unremarkable.

**Surgical procedure 1:** Four wisdom teeth were extracted for the preparation of tooth-de‐ rived materials (block-type, powder-type).

**Preparations of dentin materials:** The extracted molar was divided into the crown portion and the root portion. The crown portion was crushed under the cooling. The crushed gran‐ ules were decalcified in 0.6N HCl solution, rinsed in cold distilled water and freeze-dried. On the other hand, the root portion was perforated by using a round bar to create a porous structure. The root with many holes was decalcified in 0.6N HCl solution, rinsed and freezedried. These biomaterials are named as auto-tooth bone (ATB) by KTB.

**Surgical procedure 2:** This patient-own blood sample was centrifuged and the middle layer was collected as fibrin glue (so called concentrated growth factors: CGF) (Fig. 4a,b). The dif‐ ferent ATB materials were immersed in 0.9% NaCl solution before use (Fig. 4c). Additional‐ ly, ATB granules were mixed with the fibrin glue (CGF) prepared from autologous blood (Fig. 4d,e). The root-dentin material was divied into 2 parts by using a knife. A titanium fix‐ ture (Nobel Replace Tapered NP: 16mm) was implanted into the atrophied bone under local anesthesia (Fig. 3c,d). The root-dentin wall was grafted into the bone defect (fixture-exposed region) as veneer graft (Fig. 4f). The composite of ATB and fibrin contributed to the attach‐ ment between the grafted root-dentin and the muco-periosteal flap (Fig. 5a,b,c).

**Results and discussion:** This patient was successfully restored with the dental implant and the autograft of 2 types of ATB (root-on, powders) with autologous fibrin glue (Fig. 5d). Properly hydrated ATB should facilitate its adaption to the bone defect due to its elasticity and flexibility. The results demonstrated that autogenous tooth could be recycled as the in‐ novative biomaterials.

a: intraoral initial view (before operation), Note: a missing tooth (#11) b: X-ray photo, Note: radio-opacity of residual root c: exposed bone, Note: concave shape d: view just after Ti. fixture implantation, Note: labial bone defect

**Figure 3.** Case 1: Auto-tooth bone graft for implant placement, 17 year-old girl;

DDM is defined as an acid-insoluble dentin collagen that is absorbable, but hard to digest in human body (Fig. 2). DDM is acellular biomatrix with the micro-tube structure. DDM and DBM possess the ability to coagulate blood plasmas (Huggins & Reddi., 1973). The coagula‐ tion action of blood plasma by DDM should become advantageous for surgical operations.

Dentin formation is a dynamic and complicated process, involving interplays among a num‐ ber of molecules including type I collagen, NCPs and prtoteoglycans, which work collective‐ ly to precisely control the site and rate of apatite formation. Type I collagen secreted by odontoblasts forms the scaffold, upon which HAp crystals are deposited. In addition to type I collagen, the extracelluar matrix contains a number of NCPs which play critical roles in the

**Patient:** A 17-year-old female presented with missing teeth (#11). Clinical and radiological examinations revealed atrophied bone and fractured root residue in the region (Fig. 3a,b).

**Surgical procedure 1:** Four wisdom teeth were extracted for the preparation of tooth-de‐

**Preparations of dentin materials:** The extracted molar was divided into the crown portion and the root portion. The crown portion was crushed under the cooling. The crushed gran‐ ules were decalcified in 0.6N HCl solution, rinsed in cold distilled water and freeze-dried. On the other hand, the root portion was perforated by using a round bar to create a porous structure. The root with many holes was decalcified in 0.6N HCl solution, rinsed and freeze-

**Surgical procedure 2:** This patient-own blood sample was centrifuged and the middle layer was collected as fibrin glue (so called concentrated growth factors: CGF) (Fig. 4a,b). The dif‐ ferent ATB materials were immersed in 0.9% NaCl solution before use (Fig. 4c). Additional‐ ly, ATB granules were mixed with the fibrin glue (CGF) prepared from autologous blood (Fig. 4d,e). The root-dentin material was divied into 2 parts by using a knife. A titanium fix‐ ture (Nobel Replace Tapered NP: 16mm) was implanted into the atrophied bone under local anesthesia (Fig. 3c,d). The root-dentin wall was grafted into the bone defect (fixture-exposed region) as veneer graft (Fig. 4f). The composite of ATB and fibrin contributed to the attach‐

**Results and discussion:** This patient was successfully restored with the dental implant and the autograft of 2 types of ATB (root-on, powders) with autologous fibrin glue (Fig. 5d). Properly hydrated ATB should facilitate its adaption to the bone defect due to its elasticity and flexibility. The results demonstrated that autogenous tooth could be recycled as the in‐

dried. These biomaterials are named as auto-tooth bone (ATB) by KTB.

ment between the grafted root-dentin and the muco-periosteal flap (Fig. 5a,b,c).

initiation and regulation of HAp crystals (Qin et al., 2011).

**3. Clinical study of human dentin**

394 Advances in Biomaterials Science and Biomedical Applications

Her medical history was unremarkable.

rived materials (block-type, powder-type).

novative biomaterials.

**3.1. Case 1: Bone augmentation, 17 year-old female**

a: blood after centrifugation, Note: 3 layers b: fibrin glue; middle layer in 4a c: wettable ATB materials (block-type ⇩, powder-type) d,e: composite of powder and fibrin glue f: covering with block-type of dentin

**Figure 4.** Case 1: Auto-tooth bone (ATB) graft for implant placement, 17 year-old girl

a: fibrin glue including ATB powders (⇦) b: repositioned flap. Note: suture with nylon c: X-ray photo just after operation d: final view after prosthetic restoration

**Figure 5.** Case 1: Auto-tooth bone graft for implant placement, 17 year-old girl

#### **3.2. Case 2: DDM onlay graft and tooth autograft, 25 year-old female**

**Patient:** A 25-year-old female presented with missing teeth (#46). She lost the first molar about 12 years ago. A clinical examination revealed an atrophied bone in the region. Her medical history was unremarkable.

**Surgical procedure 1:** A non-functional vital tooth (#28) was extracted and immediately crushed with saline ice by our newly developed tooth- mill (Osteo-Mill®, Tokyo Iken Co., Ltd) at 12000rpm for 30 sec (Fig. 6) (Patent: 4953276). Briefly, vessel and blade were made in ZrO2. The crushed tooth-granules were decalcified in 2% HNO3 solution for 20 min (Murata et al., 2009). The DDM granules including cementum were rinsed in cold distilled water. Cortical perforations were performed in the atrophied bone, and DDM were immediately autotransplanted on the perforated bone under local anesthesia.

**Surgical procedure 2:** At 4 months after the first operation, a non-functional vital tooth (#18) was extracted and received the immediate root canal filling (RCF), using a new fixation de‐ vice (Fig. 7). The device was developed for tooth transplantation and replantation (Patent: 4866994).

After the bone biopsy for the tissue observation and the preparation of transplated cavity, tooth autograft was carried out into the host bone (Fig. 8a,b,d).

**Results and discussion:** The biopsy tissue showed that DDM granules were received to host, and partially replaced by new bone (Fig. 8e). This case was onlay graft of DDM on per‐ forated cortical bone (Murata et al, 1999; Murata et al, 2000). Though RCF is generally car‐ ried out at more than 4 weeks after tooth transplantation, we did immediate RCF, using the medical device. This patient was successfully restored with her own 2 teeth. This case was the immediate tooth autotransplantition with the immediate root canal filling at 4 months after DDM autograft in 2009.

a: mill, b: tooth with ice blocks, c: ZrO2 vessel, d: crushed tooth, e: DDM granules before clinical use.

**Figure 6.** Preparation of DDM using automatic tooth mill (Osteo-Mill®, Tokyo Iken)

a: fibrin glue including ATB powders (⇦) b: repositioned flap. Note: suture with nylon c: X-ray photo just after

**Patient:** A 25-year-old female presented with missing teeth (#46). She lost the first molar about 12 years ago. A clinical examination revealed an atrophied bone in the region. Her

**Surgical procedure 1:** A non-functional vital tooth (#28) was extracted and immediately crushed with saline ice by our newly developed tooth- mill (Osteo-Mill®, Tokyo Iken Co., Ltd) at 12000rpm for 30 sec (Fig. 6) (Patent: 4953276). Briefly, vessel and blade were made in ZrO2. The crushed tooth-granules were decalcified in 2% HNO3 solution for 20 min (Murata et al., 2009). The DDM granules including cementum were rinsed in cold distilled water. Cortical perforations were performed in the atrophied bone, and DDM were immediately

**Surgical procedure 2:** At 4 months after the first operation, a non-functional vital tooth (#18) was extracted and received the immediate root canal filling (RCF), using a new fixation de‐ vice (Fig. 7). The device was developed for tooth transplantation and replantation (Patent:

operation d: final view after prosthetic restoration

396 Advances in Biomaterials Science and Biomedical Applications

medical history was unremarkable.

4866994).

**Figure 5.** Case 1: Auto-tooth bone graft for implant placement, 17 year-old girl

autotransplanted on the perforated bone under local anesthesia.

**3.2. Case 2: DDM onlay graft and tooth autograft, 25 year-old female**

a: whole view, Note: the device developed for tooth transplantation and replantation b: fixed tooth, Note: corre‐ spondence to all teeth c: crown treatment, Note: periodontal ligament tissue protected from infected fine particles d: root view, Note: keeping blood even after cutting and root canal filling

**Figure 7.** New device for protecting periodontal ligament cells (Mr.FIX®, Tokyo Iken)

a: initial X-ray photo: missing tooth (#46) and atrophied bone. Non-functional tooth (⇦) for DDM b: just after DDM graft. Non-functional tooth (⇨) for next tooth autograft c: tooth auto-transplantation at 4 months after DDM graft d: DDM autograft on perforated cortical bone before suture e: biopsy: mature bone connected with DDM residue (HE section)

**Figure 8.** Case 2: 24 year-old woman
