Demineralized dentin matrix combined with recombinant human bone morphogenetic protein-2 in rabbit calvarial defects

Demineralized dentin matrix for bone regeneration in dentistry: A critical update

Over the last few decades, several new materials and techniques have been developed for bone regeneration. Scaffolds based on demineralized dentin matrix (DDM) present an attractive option due to their availability and several animal and human studies have been conducted to ascertain their utility in regenerative dentistry. The aim of this review was to summarize the recent studies conducted on DDM and used for bone grafts. PubMed, Web of Science, and Scopus were used to search for studies published within the last 10 years. The keywords and terms used were: "demineralized dentine matrix", "bone grafting", "bone augmentation" and "guided tissue regeneration" in various combinations. Original studies (in vitro, animal and human) and systematic reviews were included in the literature search. The literature search initially identified 23 studies (16 animal studies and 7 clinical reports. Most studies included in this review indicate that DDM has demonstrated promising results in a variety of dental and regenerative medicine applications. Further studies are required to completely comprehend its characteristics and prospective applications. Future studies should also focus on optimizing the processing protocols for the production of DDM-based scaffolds.

Cone-Beam Computed Tomography and Histological Findings for Socket Preservation Techniques Using Different Grafting Materials: A Systematic Review

OBJECTIVE

Socket preservation techniques have been used to maintain the ridge dimension following tooth extraction. The materials used influence the quality and quantity of newly formed bone. Therefore, the aim of this article was to systematically review the literature reporting both histological and radiographic outcomes of socket preservation techniques after tooth extraction in human subjects.

MATERIAL AND METHOD

A systematic electronic search was performed in the electronic databases. English language clinical studies that were published between 2017 and 2022 and included both histological and radiographic findings for the test and control groups. Our primary search produced 848 articles, and of these, 215 were duplicate studies. A total of 72 articles were then eligible for full-text reading.

RESULTS

The review included eight studies that met its inclusion criteria. Three outcomes were compared in the included studies. The percentage of newly formed bone ranged from 21.34 ± 9.14% to more than 50% of new bone formation. The materials that showed more than 50% of newly formed bone formation were demineralized dentin graft, platelet-rich fibrin, freeze-dried bone allograft, corticocancellous porcine, and autogenous bone. Four Studies did not report the percentage of the residual graft materials, while those who reported showed a variable range of a minimum 1.5% to more than 25%. One study did not report the changes in horizontal width at the follow-up period, while other studies ranged from 0.6 mm to 10 mm.

CONCLUSION

Socket preservation represents an efficient technique to preserve the ridge contour with satisfactory newly formed bone in the augmented site and maintaining the vertical and horizontal dimensions of the ridge.

Comparison of Bone Regeneration in Different Forms of Bovine Bone Scaffolds with Recombinant Human Bone Morphogenetic Protein-2

The aim of this study was to compare the bone regeneration ability of particle and block bones, acting as bone scaffolds, with recombinant human bone morphogenetic protein (rhBMP)-2 and evaluate them as rhBMP-2 carriers. Demineralized bovine bone particles, blocks, and rhBMP-2 were grafted into the subperiosteal space of a rat calvarial bone, and the rats were randomly divided into four groups: particle, block, P (particle)+BMP, and B (block)+BMP groups. The bone volume of the B+BMP group was significantly higher than that of the other groups (p < 0.00), with no significant difference in bone mineral density. The average adipose tissue volume of the B+BMP group was higher than that of the P+BMP group, although the difference was not significant. Adipose tissue formation was observed in the rhBMP-2 application group. Histologically, the particle and B+BMP groups showed higher formation of a new bone. However, adipose tissue and void spaces were also formed, especially in the B+BMP group. Hence, despite the formation of a large central void space, rhBMP-2 could be effectively used with block bone scaffolds and showed excellent new bone formation. Further studies are required to evaluate the changes in adipose tissue.

Prognosis of single tooth implants following alveolar ridge preservation with two recombinant human bone morphogenetic protein-2 delivery systems

Background

We previously reported similar efficacies of alveolar ridge preservation (ARP) on single extraction socket with two different E. coli derived recombinant human bone morphogenetic protein-2 (rhBMP-2) delivery systems (Cowell BMP, Cowell medi Co, Busan, Korea; β-tricalcium phosphate and hydroxyapatite particle & O-BMP, Osstem Implant Co, Busan, Korea; absorbable collagen sponge). After the trial, we completed implant therapy and observed over an average of 3 years. This follow-up study was performed retrospectively to compare result of implant treatment at the preserved alveolar ridge site.

Methods

Patients who underwent extraction of single tooth and received ARP with one of two rhBMP-2 delivery systems from October 2015 to October 2016 were enrolled. Twenty-eight patients (Group 1: Cowell BMP 14; Group 2: O-BMP 14) who underwent implant therapy and prosthetic treatment were included in study. Stability and marginal bone loss (MBL) of each implant were collected from medical charts and radiographs, and analyzed. The survival and success rates of implants were calculated.

Results

The primary implant stability represented by implant stability quotient (ISQ) for Groups 1 and 2 was 69.71 and 72.86, respectively. The secondary implant stability for Groups 1 and 2 was 78.86 and 81.64, respectively. Primary and secondary stabilities were not statistically different (P = 0.316 and 0.185, respectively). MBL at the latest follow-up was 0.014 mm in Group 1 over 33.76 ± 14.31 months and 0.021 mm in Group 2 over 40.20 ± 9.64 months, with no significant difference (P = 0.670). In addition, the success rate of implants was 100% (14/14) in Group 1 and 92.9% (13/14) in Group 2, with survival rate of 100% (14/14) in Group 1 and 92.9% (13/14) in Group 2.

Conclusions

We confirmed good prognosis in both groups as a result of implant therapy after ARP with each of two rhBMP-2 carriers.

Human Fresh Fibrin Membrane with Bone Morphogenetic Protein-2 (BMP-2) Induces Bone Formation in the Subcutaneous Tissues of Nude Mice

Autologous blood-derived fibrin glue with platelets, called the concentrated growth factor (CGF), can be prepared immediately by only the decided centrifuge without the addition of coagulation factors. Collagen materials combined with recombinant human BMP-2 have been commercially available for clinical use. The fresh CGF is auto-clot with wettability and elasticity, while most collagen membranes are derived from the cow or pig. The fresh CGF has wettability and elasticity, while collagen membranes are dry materials without elasticity. The aim of this study was to observe the microstructures of human CGF membrane and evaluate its behavior as a delivery scaffold of rhBMP-2 in the subcutaneous tissues of nude mice. Twenty-four nude mice (5-week-old, male) were used for the assessment of in vivo ectopic bone formation. Mice were received the CGF membrane as the controls and the CGF/rhBMP-2 membrane as the experimental group in the subcutaneous tissues, and harvested at 7, 10, and 14 days after the graft. Harvested samples were evaluated for the histological examination and the histomorphometric measurement was conducted to compare the residue of the CGF, as well as the new bone. Mature fibrin fibers assembled from multiple fibrillary elements and platelets with the rhBMP-2 membrane induced several bony islands and cartilage without residues of CGF at 14 days, while the CGF membrane alone was almost absorbed at 10 days and failed to induce bone formation at 14 days. These results demonstrated that the fresh, human CGF membrane could contribute to a short-term, sticky fibrin matrix for the delivery of rhBMP-2.

Histological Review of Demineralized Dentin Matrix as a Carrier of rhBMP-2

In 2007, recombinant human bone morphogenetic protein-2 (rhBMP-2) was approved for use in humans at a concentration of 1.5 mg/mL with absorbable collagen sponges as an alternative to autogenous bone grafts for alveolar ridge augmentation, defects associated with extraction sockets, and sinus augmentation. However, the use of supraphysiological doses and the insufficient retention of rhBMP-2, when delivered through collagen sponge, result in dose-dependent side effects related to off-label use. Demineralized dentin matrix (DDM), an osteoinducing bone substrate, has been used as an rhBMP-2 carrier since 1998. In addition, DDM has both microparticle and nanoparticle structures, which do not undergo remodeling, unlike bone. In vitro, DDM is a suitable carrier for BMP-2, with the continued release over 30 days at concentrations sufficient to stimulate osteogenic differentiation. In this review, we discuss the histological outcomes of DDM loaded with rhBMP-2 to highlight the biological functions of exogenous rhBMP-2 associated with the DDM carrier in clinical applications in implant dentistry. Impact Statement Demineralized dentin matrix (DDM) has been used as an recombinant human bone morphogenetic protein (rhBMP-2) carrier and osteo-inducing bone substrate to facilitate continued release and stimulate osteogenic differentiation. In this review, we discuss the histological outcomes of DDM loaded with rhBMP-2 in order to highlight the biological functions of exogenous rhBMP-2 associated with the DDM carrier in clinical applications in implant dentistry.

Similar inductive effects of enamel and dentin matrix derivatives on osteoblast-like cell response over SLA titanium surface

OBJECTIVES

The aim of this in vitro study was to investigate the behavior of osteoblasts on titanium discs under different concentrations of enamel matrix derivatives (EMD) and dentin matrix derivative (DMD).

MATERIALS AND METHODS

MC3T3-E1 osteoblast-like cells were cultivated on coated titanium SLA discs with EMD or DMD at 100 μg/ml, 1 mg/ml, 10 mg/ml and 30 mg/ml or left uncoated. Cell viability, proliferation, adhesion and migration were assessed respectively with MTT, BrdU, DAPI and scratch wound healing assays. Messenger ribonucleic acid of different genes related to osteoblastic differentiation was quantified by means of real-time quantitative PCR. Data were analyzed using student t-test for adhesion and migration assay and ANOVA for proliferation assay (p < 0.05).

RESULTS

BrdU incorporation was found in proliferative osteoblasts for both test solutions at all concentrations. Osteoblast migrated and covered approximately 70% of the wound area observed at time zero when exposed to EMD and DMD to all concentrations. The increase of gene expression was dependent on the concentration enhancement of EMD and DMD. Higher concentrations showed proliferation augmentation if compared to lower concentrations.

CONCLUSIONS

Roughness surface of Ti SLA can limit cell adhesion independent of the presence EMD or DMD. DMD enhances cell migration of osteoblasts on SLA titanium implants in a concentration-dependent manner.

Evaluation of the Bone Regeneration Effect of Recombinant Human Bone Morphogenic Protein-2 on Subperiosteal Bone Graft in the Rat Calvarial Model

The aim of this study was to evaluate the bone regeneration effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on a subperiosteal bone graft in a rat model. A subperiosteal space was made on the rat calvarium, and anorganic bovine bone (ABB), ABB/low bone morphogenetic protein (BMP) (5 µg), and ABB/high BMP (50 µg) were grafted as subperiosteal bone grafts. The new bone formation parameters of bone volume (BV), bone mineral density (BMD), trabecular thickness (TbTh), and trabecular spacing (TbSp) were evaluated by microcomputed tomography (µ-CT), and a histomorphometric analysis was performed to evaluate the new bone formation area. The expression of osteogenic markers, such as bone sialoprotein (BSP) and osteocalcin, were evaluated by immunohistochemistry (IHC). The ABB/high BMP group showed significantly higher BV than the ABB/low BMP (p = 0.004) and control groups (p = 0.000) and higher TbTh than the control group (p = 0.000). The ABB/low BMP group showed significantly higher BV, BMD, and TbTh than the control group (p = 0.002, 0.042, and 0.000, respectively). The histomorphometry showed significantly higher bone formation in the ABB/low and high BMP groups than in the control group (p = 0.000). IHC showed a high expression of BSP and osteocalcin in the ABB/low and high BMP groups. Subperiosteal bone grafts with ABB and rhBMP-2 have not been studied. In our study, we confirmed that rhBMP-2 contributes to new bone formation in a subperiosteal bone graft with ABB.

Nano-Structured Demineralized Human Dentin Matrix to Enhance Bone and Dental Repair and Regeneration

Demineralized dentin matrix (DDM), derived from human teeth, is an excellent scaffold material with exciting bioactive properties to enhance bone and dental tissue engineering efficacy. In this article, first the nano-structure and bioactive components of the dentin matrix were reviewed. Then the preparation methods of DDM and the resulting properties were discussed. Next, the efficacy of DDM as a bone substitute with in vitro and in vivo properties were analyzed. In addition, the applications of DDM in tooth regeneration with promising results were described, and the drawbacks and future research needs were also discussed. With the extraction of growth factors from DDM and the nano-structural properties of DDM, previous studies also broadened the use of DDM as a bioactive carrier for growth factor delivery. In addition, due to its excellent physical and biological properties, DDM was also investigated for incorporation into other biomaterials design and fabrication, yielding great enhancements in hard tissue regeneration efficacy.

Volumetric, Radiographic, and Histologic Analyses of Demineralized Dentin Matrix Combined with Recombinant Human Bone Morphogenetic Protein-2 for Ridge Preservation: A Prospective Randomized Controlled Trial in Comparison with Xenograft

The aim of this study was to evaluate the clinical, volumetric, radiographic, and histologic aspects of autogenous demineralized dentin matrix (DDM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) used for ridge preservation, compared to those of deproteinized bovine bone with collagen (DBBC). Following atraumatic extraction, the socket was filled with DBBC, DDM, or rhBMP-2/DDM. Scanned images of dental casts and cone beam computed tomographs (CBCT) were superimposed for the calculation of soft and hard tissue volume alteration. Preoperative and postoperative measurements of the height and width of the alveolar ridge were compared using CBCT images. After 4 months, bone specimens were harvested for histomorphometric assessment. Loss of hard and soft tissue volume occurred at 4 months after extraction and ridge preservation in all groups. No volumetric differences were detected among the three groups before and 4 months after ridge preservation. The reduction in the horizontal width at 5 mm was higher in the DBBC compared to the DDM. Histologically, approximately 40% newly formed bone was founded in rhBMP-2/DDM group. The autogenous dentin matrix used to fill the socket was as beneficial for ridge preservation as conventional xenografts. The combination of rhBMP-2 with dentin matrix also demonstrated appreciable volumetric stability and higher new bone formation compared to DDM alone and DBBC.

Demineralized Dentin Matrix (DDM) As a Carrier for Recombinant Human Bone Morphogenetic Proteins (rhBMP-2)

A bone graft and bone graft substitute should have at least one of the following properties: it should be (1) osteogenic, (2) osteoinductive and/or (3) osteoconductive. In addition, bone graft substitutes should be biocompatible and bioresorbable as well as easy to use and cost effective. Autologous cancellous bone is the clinical gold standard in bone grafting procedures1, 4 and it has osteogenic, osteoinductive, and osteoconductive properties. Because of disadvantages associated with harvesting autologous bone graft material, such as requiring an additional operation and possible donor site morbidity, there is a need for an alternative in terms of enhancing the bone healing for the treatment of large bony defects. One possible option is a newly developed biomaterial, the demineralized dentin matrix (DDM). It is based on autogenous tooth dentin and is produced through demineralization. It is osteoconductive and osteoinductive due to the fact that dentin contains extracellular Type I collagen and various growth factors. Based on the demineralization process the factors stay available to the host environment. In 1965, Urist already showed the formation of ectopic bone after implanting DDM into muscle pouches in rodents. DDM is used for example in dental surgery in the treatment of extraction socket preservation and guided bone regenerations. It functions as a scaffold to support bone regeneration, but can also be used as a carrier for rhBMP-2. When DDM serves as a carrier, it combines the properties of the grafting material with those of the delivered substances. This chapter will present the experimental and clinical studies of DDM for rhBMP-2 carrier as well as alternatives of bone graft substitute.

Evaluation of bone healing using rhBMP-2 soaked hydroxyapatite in ridge augmentation: a prospective observational study

Background

The goal of this study is to evaluate complication and effectiveness of alveolar ridge augmentations using a hydroxyapatite-based alloplastic bony substitute with rhBMP-2.

Methods

A total of 10 patients (4 males, 6 females; 58.5 ± 8.6 years) participated in this clinical research. Alveolar ridge augmentations were performed in edentulous (4 maxillary posterior, 5 mandibular posterior, and 1 mandibular anterior) regions. Anorganic bovine bone (ABB; Bio-Oss®, Geistlich Pharma AG, Wolhusen, Switzerland) was used as the bone graft material in the control group (n = 5)) while hydroxyapatite-based alloplastic bony substitute with rhBMP-2(HA+rhBMP-2; NOVOSIS®-Dent, CGBio Inc., Seongnam, Korea) was used in the experimental group (n = 5). In order to evaluate relative changes in bone volume and resorption rate of the bone graft material, CBCT radiographs were taken immediately and at 4 months after the bone graft in all subjects. Among the 10 patients, 8 received dental implants in Seoul National University Bundang Hospital, while the others received in local clinics. Bone specimens for further histomorphometric examinations were gained from these 8 patients using trephine burs during the implant placements. Clinical, radiographic, and histomorphometric evaluations were focused because of the small sample size.

Results

When CBCT radiographs were compared between immediately and at 4.07 ± 0.13 months after the bone graft, both alveolar bone widths (ABB 2.52 ± 0.18 mm, HA+rhBMP-2 1.75 ± 0.85 mm) and heights (ABB 1.68 ± 0.17 mm, HA+rhBMP-2 1.57 ± 0.28 mm) increased in the two groups. Resorption rates of transplanted bone graft material in the alveolar bone widths and heights were (ABB 29.7 ± 8.8%, HA+rhBMP-2 31.5 ± 7.4%) and (ABB 39.2 ± 21.8%, HA+rhBMP-2 52.6 ± 6.5%), respectively. Histomorphometrically, ABB group showed bone formation via osteoconduction and HA+rhBMP-2 group via osteoinduction. HA+rhBMP-2 group showed more bone formation around the bone graft materials than the ABB group. Postoperative complications were not found in all subjects.

Conclusions

Our study had following conclusions: (1) Ridge augmentations using HA+rhBMP-2 could be clinically useful to supplement implant placements in edentulous regions. (2) Serious postoperative complications related to the graft material did not occur.

Electronic supplementary material

The online version of this article (10.1186/s40902-017-0138-9) contains supplementary material, which is available to authorized users.

Demineralized dentin matrix scaffolds for alveolar bone engineering

From the point of view of implant dentistry, this review discusses the development and clinical use of demineralized dentin matrix (DDM) scaffolds, produced from the patient's own extracted teeth, to repair alveolar bone defects. The structure and the organic and inorganic components of DDM are presented to emphasize the similarities with autogenous bone. Studies of DDM properties, such as osteoinductive and osteoconductive functions as well as efficacy and safety, which are mandatory for its use as a bone graft substitute, are also presented. The clinical applications of powder, block, and moldable DDM are discussed, along with future developments that can support growth factor and stem cell delivery.