Biomedical Engineering Reference
In-Depth Information
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
initiation and regulation of HAp crystals (Qin et al., 2011).
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 freeze-
dried. 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.
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