Case Report |
Corresponding author: Nikolay Kanazirski ( nkanazirski@gmail.com ) © 2022 Nikolay Kanazirski, Petya Kanazirska.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kanazirski N, Kanazirska P (2022) Auto-tooth bone graft material for reconstruction of bone defects in the oral region: case reports. Folia Medica 64(1): 162-168. https://doi.org/10.3897/folmed.64.e59099
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We present some clinical cases of autogenous tooth graft – a modern method in which the extracted teeth are processed into a demineralised dentin matrix (DDM) and are then immediately transplanted into the post-extraction sockets or bone defects.
We included patients with jaw lesions due to chronic inflammatory conditions, cystic formations, or peri-implantitis. After removing the pathological processes and tissues, we performed curettage with an Er-YAG laser and treated the bone structures in the borderline area. Then auto-tooth bone (ATB) graft material was applied. The clinical results showed favourable wound healing and good bone integration of implants. Radiological studies showed stimulation and acceleration of bone regeneration with alveolar crest resorption of graft material of no more than 10%. Histological examination found new bone formation which was induced by the osteo-inductive material.
On the basis of the clinical outcomes and the favourable healing process with a very good bone integration of the DDM, we can recommend this method as an option for bone defect reconstruction. The satisfactory quantity (up to 3 grams per molar) and quality of the demineralised dentin matrix determine a relatively low cost of bone grafting.
auto-tooth bone graft system, guided tissue regeneration with autogenous bone graft, demineralised dentin matrix
Various graft materials are used for reconstruction of alveolar bone defects in clinical practice. These include allografts (demineralised and lyophilised human bone), xenografts (bovine bone, porcine bone, and coral), and alloplastic materials (biological ceramics, b-tricalcium phosphate [b-TCP] and hydroxyapatite). They are indifferent, osteoconductive and osteoinductive with regard to their absorption by the body and new bone formation.
A good bone graft material should have three properties: 1) osteoconduction, which provides the scaffold for bone regeneration; 2) osteoinduction, which promotes formation of bone from undifferentiated cells and preosteoblasts; 3) osteogenesis, the induction of cells contained in the graft to stimulate bone regeneration.[
Bone graft material should stabilise the blood clot and provide a biomechanical scaffold for cell migration, proliferation, and differentiation. It should contain functional proteins and peptides, such as growth factors, and provide resorption and remodelling during the period of new bone formation. Collagen-based materials, especially of type I, have attracted attention because of their ability to improve cellular responses of osteogenic lines, thus ensuring better bone regeneration.[
The tooth is increasingly attracting attention as a material for alveolar bone regeneration. It is composed of an organic matrix and an inorganic reinforcing phase of hydroxyapatite. Radial arrays of dense type I collagen fibrils, which make up 90% of the organic matrix, and non-cellular acidic proteins play an important role in calcification.[
Raw tooth (non-demineralized) cannot easily induce new bone formation due to its high mineral content, high crystallinity and low porosity, which can impede the migration, attachment and proliferation of vessels and mesenchymal cells.[
Young-Kyun Kim et al. conducted research on the development of biomaterials using human teeth in 1993. After long research based on an analysis of the inorganic and organic components, surface structure and histological evidence of the healing process in the samples collected after clinical application, the authors concluded that the use of bone graft material of autogenous teeth resulted in excellent reconstruction of the bone. Since 2008, Kim et al. developed the auto-tooth bone graft (ATB; Tooth Bank Co; Seoul Korea) methodology. The authors make graft material in the form of powder, chips or a block of extracted teeth and transplant them into the patients from whom the teeth were extracted.[
In addition to excellent osteoinductive and osteoconductive properties, the ATB graft material avoids the limiting factors of allografts, xenografts, and alloplastic materials, such as reduced function, potential risk of infection, unsatisfactory resorption, long recovery time, and high costs.[
A disadvantage of the ATB graft material is that acids are used for the demineralization process, and prolonged exposure to acid can have a negative effect on non-collagenous proteins involved in the formation of new bones. To overcome these limiting factors, other authors propose a modified ultrasound technology for the process of demineralization of the tooth graft.[
After the tooth to be used for graft material is extracted, it is mechanically cleaned of soft tissue and pulp (Fig.
The cleaned tooth is placed in a mechanical mill in which it is crushed. It is then sieved through two sieves, and the larger particles, which are composed mainly of enamel, are discarded. Thus, a powder material with a particle size between 200 and 1000 nm is obtained (Figs
Preparation of the extracted tooth: A) extracted; B) mechanically cleaned tooth of soft tissue; C) cleaned tooth of pulp.
A 56-year-old female patient with peri-implantitis in the area of tooth 36. Intraoral radiography performed 6 months after implant placement showed bone resorption in the upper third of the implant (Fig.
A) Intraoral X-ray of the implant in the area of 36; B) preparation of the flap; C) measured the implant’s stability; D) Granulation tissue ablation and bone remodeling with Er-YAG laser; E) Filling the bone defect with ATB graft material; F) Coating the graft material with PRF membrane; G) adaptation and suturing of the mucoperiosteal flap; H) control radiography after three months; K) Prosthetic rehabilitation of the implant.
After obtaining the graft material, a mucoperiosteal envelope flap was raised in the area of the implant (Fig.
Three months after the placement of the ATB graft material, a follow-up radiograph was performed – it showed that the newly formed bone around the implant had good density characteristics and height, and no significant alveolar crest resorption was found (Fig.
No complications were observed six months after prosthetic loading (Fig.
A 25-year-old male patient with a radicular cyst of tooth 46. Cone-beam computed tomography (CBCT) showed a hypodense oval lesion around the two roots of tooth 46, which had homogeneous structure, with dimensions of 8.88×6.89 mm, distinct borders and a perifocal sclerotic wall (Fig.
Six months later, follow-up computed tomography was performed, which showed excellent bone remodelling of the graft material, with good density and minimal alveolar crest resorption. Measurements were made for the scheduled implantation (Fig.
At the second clinical visit, after raising a flap, biological material was taken from the bone in the graft area for histological analysis. Using a bone trephine bur with a diameter of 2 mm, 5 mm of bone was taken from the boundary zone between the graft and the normal bone. The specimen was fixed with 10% formalin solution and sent for histological analysis. On histological sections, 6 months after placement of the ATB graft material, remodelling in the marginal areas of the graft material and stable osteointegration with the surrounding bone were observed. The newly formed bone has an approximate volume of 33.0% and excellent remodelling of the bone trabeculae. The graft material was incompletely absorbed and the volume of residual graft material was 26.8% (Fig.
An implant was placed, without complications during the procedure. The primary stability of the implant in the buccolingual and mesiodistal directions was measured, which featured good levels –73 ISQ.
Three months after the implant placement, a follow-up radiograph was performed, which showed that the newly formed bone around the implant had good density characteristics, and no significant alveolar crest resorption was found (Fig.
Newly formed bone demonstrating the occurrence of remodeling was identified around the implanted ATB powder. Remodeling of the tooth elements was observed at the bone-implant interfaces (H&E staining): A) ×40; B) ×100; C) ×200.
A 45-year-old male patient with pronounced clinical symptoms of an exacerbated inflammatory process in the area of the attached gingiva of tooth 26. The performed intraoral radiograph showed vertical bone resorption up to the apical third of the mediovestibular root of tooth 26, with involvement of the trifurcation (Fig.
With a view to alveolar bone prevention and scheduled implantation, tooth 26 was extracted and ATB graft material was obtained according to the described protocol. No complications occurred in the postoperative period.
Radiography performed six months later showed good remodelling of the graft material, with normal bone structure and density (Fig.
The outcomes of our clinical cases are identical to those studied by many other authors.[
The results of our histological examination were similar to those of other studies. Appositional bone growth around the ATB graft material was observed, and its resorption implies that the demineralised tooth was osteoconductive with a remodelling characteristic.[6,7,15-18] According to Eun-Seok Kim, the most interesting histological features are the appearance of fusion-like integration between the two matrices of the graft and new bone. This suggests that dentinal tubules provide niches for the cells involved in osteogenesis.[
A reasonable explanation of the good results is the high biocompatibility of autogenous tissue and its porous collagen-based structure, which is beneficial for cellular function. Our results confirm those reported in other studies –in particular, that the use of this graft material promotes a rapid healing effect and the newly formed bone has a good radiologically determined density and struc- ture.[
The good clinical outcomes and the favourable healing process with the desired bone integration give us grounds to recommend this method as an option for bone defect reconstruction. The satisfactory quantity (up to 3 grams per molar) and quality of the demineralised dentin matrix determine a relatively low cost of bone grafting.