Demineralized Dentin Matrix Research Articles

Clinical outcome of using decade-old demineralized dentin matrix in bone grafting: a case report

Clinical outcome of using decade-old demineralized dentin matrix in bone grafting: a case report

Effect of Bleaching Treatments on the Mechanical Properties of the Dentin Matrix and on Collagen Biodegradation by Endogenous Protease.

This study evaluated the mechanical properties of demineralized dentin matrix submitted to different bleaching treatments, as well as the changes in mass and collagen biodegradation brought about by endogenous protease. Dentin collagen matrices were prepared to receive the following treatments (n=12): no bleaching treatment (C-control), 10% carbamide peroxide (CP-Opalescence PF, Ultradent, South Jordan, UT, USA) 10%/8 hours/ day/14 days, and 40% hydrogen peroxide (HP-Opalescence Boost, Ultradent), 40 minutes per session/3 sessions. The dentin matrices were evaluated for elastic modulus and mass before and after treatments and ultimate tensile strength after treatments. The solution collected during storage was evaluated for hydroxyproline release. There was no statistically significant difference between CP and C in terms of the elastic modulus (p=0.3697) or mass variation (p=0.1333). Dentin beams treated with HP and C presented significant mass loss after the first session (p=0.0003). HP treatment led to complete degradation of collagen matrices after the second bleaching session. After the second session, CP showed higher hydroxyproline concentration than C (p<0.0001). Ultimate tensile strength was lower for CP than C (p=0.0097). CP did not affect the elastic modulus or the dentin collagen matrix mass but did promote hydroxyproline release by endogenous protease and reduce the ultimate tensile strength. HP significantly affected the mechanical properties of dentin and promoted complete degradation of the demineralized dentin collagen matrix.

Comparison of clinical efficacy between autologous partially demineralized dentin matrix and deproteinized bovine bone mineral for bone augmentation in orthodontic patients with alveolar bone deficiency: a randomized controlled clinical trial

BackgroundIt is common to see patients who need orthodontic treatment but with insufficient alveolar bone volume. However, safe and effective tooth movement requires sufficient alveolar bone width and height. The aim of this study is to compare the bone augmentation efficacy of Autologous Partially Demineralized Dentin Matrix (APDDM) and Deproteinized Bovine Bone Mineral (DBBM) in orthodontic patients with insufficient bone by using a randomized controlled clinical trial approach.Materials and methodsTwenty-seven orthodontic patients involving 40 posterior teeth alveolar sites (n = 40) with insufficient alveolar bone volume were randomly divided into a control group (n = 20) and an experimental group (n = 20). The patients in the experimental group were treated with APDDM, and those in the control group were treated with DBBM. After surgery, the adjacent teeth are moved toward the bone grafting sites according to the orthodontic treatment plan. Patients completed a postoperative response questionnaire by the Visual Analogue Scale (VAS) score to indicate pain and swelling in the bone grafted area at the time of suture removal; and CBCT scans were conducted before surgery, 6 months and 2 years after surgery to assess changes in buccal and central alveolar heights, as well as widths at the alveolar ridge apex and 3 mm, 5 mm below the apex, respectively. The CBCT image sequences were imported into Mimics 21.0 software in DICOM format. The data of the patients in both groups were collected and analyzed by SPSS 25.0.ResultsThe VAS scores were significantly lower in the APDDM group than in the DBBM group (p < 0.05). Significant increases were observed in alveolar bone height and width at 6 months and 2 years postoperative (p < 0.05); At 2 years, the APDDM group exhibited a reduction in buccal crest height and in 3 mm, 5 mm width below alveolar ridge apex, relative to 6 months (p < 0.05), while the DBBM group showed a decrease only in the central height of the alveolar bone (p < 0.05). There was a significant bone augmentation increase found only 3 mm below the alveolar ridge apex in the APDDM group compared with the DBBM group among all 6 months group comparison (p < 0.05). At 2 years, the augmentation effects were similar across both groups (p > 0.05).ConclusionRadiomics analysis indicates that APDDM serves as a viable bone augmentation material for orthodontic patients with insufficient alveolar bone volume, achieving comparable clinical efficacy to DBBM. Additionally, APDDM is associated with a milder postoperative response than DBBM.The registration number (TRN)ChiCTR2400084607.

Evaluation of Monomer-containing Isocyanate Groups on Stabilizing Demineralized Dentin Matrix Against Bond Interface Degradation.

To evaluate the effect of urethane methacrylate precursor (UMP) on the enzymatic resistance of demineralized dentin (DD) matrices. Experimental treatments containing 0 (control), 1, and 5 mmol/L UMP dissolved in an acetone (Ace) solution were formulated. Dentin matrix specimens were demineralized in vitro and immersed in the experimental treatments for 1 h. The treated specimens were then stored in 0.1 mg/mL collagenase solution for 24 h, after which their dry mass loss and hydroxyproline (HYP) release were assessed. The swelling ratios of specimens in each group were also evaluated. The interaction between UMP and the dentin matrix was observed using field-emission scanning electron microscopy (FE-SEM). Endogenous enzyme activity in dentin was evaluated using confocal laser scanning microscopy (CLSM). Compared with the other treatment groups, treatment with 1 mM and 5 mM UMP-Ace significantly decreased the dry mass loss, HYP release and swelling ratio of the DD matrix (p < 0.05). FE-SEM and CLSM observations showed that treatment with UMP-Ace protected the structure of the dentin matrix and decreased porosity within the dentin-collagen network. Treatment with 1 mM and 5 mM UMP-Ace protects DD matrix against collagenase degradation and may be clinically useful for improving the durability of the hybrid layer.

STMP and PVPA as Templating Analogs of Noncollagenous Proteins Induce Intrafibrillar Mineralization of Type I Collagen via PCCP Process.

The phosphorylated noncollagenous proteins (NCPs) play a vital role in manipulating biomineralization, while the mechanism of phosphorylation of NCPs in intrafibrillar mineralization of collagen fibril has not been completely deciphered. Poly(vinylphosphonic acid) (PVPA) and sodium trimetaphosphate (STMP) as templating analogs of NCPs induce hierarchical mineralization in cooperation with indispensable sequestration analogs such as polyacrylic acid (PAA) via polymer-induced liquid-like precursor (PILP) process. Herein, STMP-Ca and PVPA-Ca complexes are proposed to achieve rapid intrafibrillar mineralization through polyelectrolyte-Ca complexes pre-precursor (PCCP) process. This strategy is further verified effectively for remineralization of demineralized dentin matrix both in vitro and in vivo. Although STMP micromolecule fails to stabilize amorphous calcium phosphate (ACP) precursor, STMP-Ca complexes facilely permeate into intrafibrillar interstices and trigger phase transition of ACP to hydroxyapatite within collagen. In contrast, PVPA-stabilized ACP precursors lack liquid-like characteristic and crystallize outside collagen due to rigid conformation of PVPA macromolecule, while PVPA-Ca complexes infiltrate into partial intrafibrillar intervals under electrostatic attraction and osmotic pressure as evidenced by intuitionistic 3D stochastic optical reconstruction microscopy (3D-STORM). The study not only extends the variety and size range of polyelectrolyte for PCCP process but also sheds light on the role of phosphorylation for NCPs in biomineralization.

The effect of autologous demineralized dentin matrix on postoperative complications and wound healing following lower third molar surgery: A split-mouth randomized clinical trial

Background/purposeAutologous dentin materials are among the most promising bone substitutes for preventing osseous defects on the distal side of the lower second molar. This study aimed to investigate the effects of autologous demineralized dentin matrix on postoperative complications and wound healing after lower third molar surgery. Materials and methodsThirteen patients with bilateral symmetrical lower third molars participated in this split-mouth randomized clinical trial. After removal surgery, one socket of the lower third molar was grafted with dentin material (demineralized dentin matrix side), and a piece of collagen sponge was used for the tooth socket of the remaining side (control side). The upper third molar on the same lateral side was extracted immediately before lower third molar surgery and used to create a demineralized dentin matrix according to the manufacturer's protocol (KometaBio). After lower third molar surgery, pain, swelling, trismus, and Inflammatory Proliferative Remodeling Scale scores were used to evaluate postoperative complications and wound healing. ResultsPain, swelling, and trismus of the demineralized dentin matrix and control sides were not significantly different at any assessment time (P > 0.05). The wound-healing scores of the demineralized dentin matrix side were better than those of the control side; however, the differences were only significant at 7th and 30th days (P < 0.05). ConclusionGrafting autologous demineralized dentin matrix into the tooth socket did not increase the postoperative complications after lower third molar surgery. However, wound healing on the graft side was comparatively better than that on the control side. Clinicaltrials.gov identifierNCT06073639, date 10 October, 2023. This is a retrospectively registered trial.

Bone graft for alveolar cleft by using demineralized dentin matrix

Autogenous bone grafts remain the standard for cleft alveolus surgery despite absorption tendencies and donor site complications. DDM, derived from teeth, demonstrates promising osteoinductive properties comparable to autogenous bone. This paper aims to introduce and discuss cases of bone graft for cleft alveolus utilizing demineralized dentin matrix (DDM) derived from teeth, highlighting the outcomes and potential advantages of DDM in cleft alveolus reconstruction. A nine-year-old patient underwent cleft alveolus surgery with bilateral bone grafting. To address volume limitation of DDM, the surgical procedure involved harvesting bone from the anterior iliac crest. Postoperative radiographic assessments at nine months revealed favorable bone integration in the cleft region. The study advocates for further exploration of DDM applications in clinical recommends.

In Vivo Evaluation of Regenerative Osteogenic Potential Using a Human Demineralized Dentin Matrix for Dental Application.

The use of a demineralized dentin matrix (DDM) has garnered substantial importance in dentistry. This study was carried out to evaluate the osteoinductive performance of DDM in comparison to nano-hydroxyapatite (n-HA) on calvarial critical-sized bone defect. Two critical-sized defects (CSDs) were bilaterally trephined in the calvarium of sixteen healthy white rabbits. The rabbits were categorized into four groups: in group 1, the defect was left empty; in group 2, defects were filled with sodium alginate (SA) hydrogel as a sole material; in group 3, defects were treated with nano-hydroxyapatite hydrogel (NHH); in group 4, defects were treated using demineralized dentin matrix hydrogel (DDMH). Histological and immunohistochemical analyses were carried out to evaluate the total areas of newly formed bone. The DDMH group showed that new woven bone tissue progressively bridged the defect area while there was no bone in the control group. Collagen expression was significantly different in the DDMH- and NHH-treated groups compared to in the SA group at 4 and 8 weeks (p < 0.01). OCN expression was significantly higher in the DDMH group in comparison to in the NHH or SA groups at 8 weeks (p < 0.01). The DDMH group exhibited significantly higher levels of new bone formation compared to the NHH group at both 4 and 8 weeks post-surgically.

Antimicrobial Peptide- and Dentin Matrix-Functionalized Hydrogel for Vital Pulp Therapy via Synergistic Bacteriostasis, Immunomodulation, and Dentinogenesis.

The preservation of vital pulps is crucial for maintaining the physiological functions of teeth; however, vital pulp therapy (VPT) of pulpitis teeth remains a substantial challenge due to uncontrolled infection, excessive inflammation, and limited regenerative potential. Current pulp capping agents have restricted effects in the infectious and inflammatory microenvironment. To address this, a multifunctional hydrogel (TGH/DM) with antibacterial, immunomodulatory, and mineralization-promoting effects is designed. The antimicrobial peptide (AMP) and demineralized dentin matrix are incorporated into the hydrogel, achieving sustainable delivery of AMP and a cocktail of growth factors. In vitro results show that TGH/DM could kill endodontic microbiota, ameliorate inflammatory responses of human dental pulp stem cells (hDPSCs), and prompt odontogenic differentiation of inflammatory hDPSCs via activation of peroxisome proliferator-activated receptor gamma. In vivo results suggest that TGH/DM is capable of inducing M2 phenotype transformation of macrophages in mice and fostering the regeneration of the dentin-pulp complex in inflamed pulps of beagle dogs. Overall, this study first proposes the synergistic regulation of AMP and tissue-specific extracellular matrix for the treatment of pulpitis, and the advanced hydrogel provides a facile and effective way for VPT.

Comparison of the osteogenic effects of demineralized dentin matrix and acellular dentin matrix.

This study aims to compare the osteogenic effects of implanting demineralized dentin matrix and acellular dentin matrix in bone defect areas. Demineralized dentin matrix and acellular dentin matrix were prepared. Twenty-four male SPF-grade SD rats were randomly divided into four groups: demineralized group (group A), acelluar group (group B), Bio-Oss bone powder group (group C), and blank control group (group D), with six rats in each group. All rats were subjected to general anesthesia to prepare bilateral femoral bone defects. Rats in groups A, B, and C were implanted with demineralized dentin matrix, acellular dentin matrix, and Bio-Oss bone powder at the bone defect area, respectively, while rats in group D were not implanted with any material. At 4 and 8 weeks after surgery, three rats were randomly executed in each group. The healing of the bone defect area was analyzed through gross observation. The concentrations of osteogenic indicators bone morphogenetic protein-2 (BMP-2) and alkaline phosphatase (ALP) were detected by serology. The distribution of high-density gray area (representing bone healing) in the bone defect area was observed by X-ray examination, and the formation of new bone was observed by histomorphology. The rate of new bone formation was calculated. At 4 and 8 weeks, the bone formation ability of group A was more active than that of the other groups; the concentrations of BMP-2 and ALP in group A were higher than those in the other groups, and the differences were statistically significant (P<0.05). At 8 weeks, the imaging observation showed that the high-density gray area in the bone defect of group A was evenly distributed. The histomorphological observation showed the regular arrangement of bone matrix in group A. The rate of new bone formation in group A was 28.51%±0.55% at 4 weeks and 32.57%±2.28% at 8 weeks, both of which were significantly higher than those in the other groups (P<0.05). Demineralized dentin matrix has better osteogenic potential than acellular dentin matrix.

A novel bi-layered asymmetric membrane incorporating demineralized dentin matrix accelerates tissue healing and bone regeneration in a rat skull defect model.

Objectives: The technique of guided bone regeneration (GBR) has been widely used in the field of reconstructive dentistry to address hard tissue deficiency. The objective of this research was to manufacture a novel bi-layered asymmetric membrane that incorporates demineralized dentin matrix (DDM), a bioactive bone replacement derived from dentin, in order to achieve both soft tissue isolation and hard tissue regeneration simultaneously. Methods: DDM particles were harvested from healthy, caries-free permanent teeth. The electrospinning technique was utilized to synthesize bi-layered DDM-loaded PLGA/PLA (DPP) membranes. We analyzed the DPP bilayer membranes' surface topography, physicochemical properties and degradation ability. Rat skull critical size defects (CSDs) were constructed to investigate in vivo bone regeneration. Results: The synthesized DPP bilayer membranes possessed suitable surface characteristics, acceptable mechanical properties, good hydrophilicity, favorable apatite forming ability and suitable degradability. Micro-computed tomography (CT) showed significantly more new bone formation in the rat skull defects implanted with the DPP bilayer membranes. Histological evaluation further revealed that the bone was more mature with denser bone trabeculae. In addition, the DPP bilayer membrane significantly promoted the expression of the OCN matrix protein in vivo. Conclusions: The DPP bilayer membranes exhibited remarkable biological safety and osteogenic activity in vivo and showed potential as a prospective candidate for GBR applications in the future.

Root coverage achieved with a connective tissue graft overlaid onto allogeneic demineralized dentin matrix incorporated with rhBMP-2

Autogenous demineralized dentin matrix (DDM) has been widely used in implant dentistry and highlighted as a potential carrier of recombinant human bone morphogenetic protein-2 (rhBMP-2). Allogeneic DDM (Allo-DDM) is comparable to autogenous DDM in safety and effectiveness. The various endogenous growth factors in dentin, including BMP, transform-ing growth factor, fibroblast growth factor, and insulin growth factor suggest that DDM incorporated with rhBMP-2 (DDM/ rhBMP-2) may exert a synergistic effect that promotes soft tissue healing through angiogenic activity, in addition to its osteoinductivity. This case report describes a successful outcome of root coverage where connective tissue graft (CTG) was overlaid onto Allo-DDM incorporated with rhBMP-2 (Allo-DDM/rhBMP-2).

Promoting effect of proanthocyanidin-amorphous calcium phosphate nanoparticles on biomimetic mineralization of demineralized dentin

Biomimetic mineralization is a new strategy for dentin repair emerging in the field of minimally invasive dentistry in recent years. However, the degradation of collagen fibrils and the lack of sustained supply of calcium and phosphorus ions are two main limitations during dentin biomimetic mineralization. Herein, by integrating the dual effects of collagen protection and mineralization induction, we proposed a novel nanoscale platform called proanthocyanidin-amorphous calcium phosphate nanoparticles (PA-ACP/NPs), which were solid nanospheres with uniform size and good biocompatibility, and could continuously release Ca and P ions in neutral or weak acidic microenvironment. PA-ACP/NPs effectively decreased the endogenous collagenase activity of demineralized dentin matrix and protected demineralized dentin collagen from degradation. Compared with the control ACP/NPs, PA-ACP/NPs induced nearly complete intrafibrillar mineralization of collagen fibrils and facilitated remineralization of demineralized dentin. As an additive of dental adhesives for the preliminary exploration of clinical application forms, the adhesive containing 20 wt% PA-ACP/NPs induced biomimetic intrafibrillar mineralization within the bonding interface after one and three months. PA-ACP/NPs nanoscale delivery exhibits excellent effects on stabilizing collagen fibrils and provides a long-term supply of mineral ions for dentin biomimetic mineralization, being a promising strategy for dentin biomimetic repair.

A bi-layered asymmetric membrane loaded with demineralized dentin matrix for guided bone regeneration

ObjectivesGuided bone regeneration (GBR) is a well-established method for repairing hard tissue deficiency in reconstructive dentistry. The aim of this study was to investigate the barrier function, osteogenic activity and immunomodulatory ability of a novel bi-layered asymmetric membrane loaded with demineralized dentin matrix (DDM). MethodsDDM particles were harvested from healthy, caries-free permanent teeth. Electrospinning technique was utilized to prepare bi-layered DDM-loaded poly(lactic-co-glycolic acid) (PLGA)/poly(lactic acid) (PLA) membranes (abbreviated as DPP bilayer membranes). We analyzed the membranes' surface properties, cytocompatibility and barrier function, and evaluated their osteogenic activity in vitro. In addition, its effects on the osteogenic immune microenvironment were also investigated. ResultsSynthetic DPP bilayer membranes presented suitable surface characteristics and satisfactory cytocompatibility. Transwell assays showed significant fewer migrated cells by the DPP bilayer membranes compared with blank control, with or without in vitro degradation (all P < 0.001). In vitro experiments indicated that our product elevated messenger ribonucleic acid (mRNA) expression levels of osteogenic genes alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN) and runt-related transcription factor 2 (Runx2). Among all groups, 20% DPP bilayer membrane displayed highest ALP activity (P < 0.001). Furthermore, DPP bilayer membranes enhanced the mRNA expression of M2 macrophage markers and increased the proportion of CD206+ M2 macrophages by 100% (20% DPP: P < 0.001; 30% DPP: P < 0.001; 40% DPP: P < 0.05), thus exerting an inflammation suppressive effect. ConclusionsDPP bilayer membranes exhibited notable biological safety and osteogenic activity in vitro, and have potential as a prospective candidate for GBR approach in the future.

Autologous tooth bone graft block compared with advanced platelet-rich fibrin in alveolar ridge preservation: A clinico-radiographic study.

To determine the clinico-radiographic efficiency of partially demineralized dentin matrix block (PDDM block), a mixture of PDDM with advanced-platelet-rich fibrin+ (A-PRF+) and injectable platelet-rich fibrin versus A-PRF+ alone in alveolar socket preservation. Sixteen molar teeth indicated for extraction were randomly assigned into two groups. For the test group, sockets were packed with PDDM block and control group, with A-PRF+ plug alone. Clinical and radiographic cone-beam computed tomography methods were used to assess the horizontal and vertical ridge dimensional changes at baseline and 4 months. Clinically, the mid buccal and palatal crestal height (10.25 ± 0.86 and 9.75 ± 0.28 mm) and alveolar ridge width (11.37 ± 0.25 mm) were significantly higher in the test group as compared to the control group, 4 months after tooth extraction (P < 0.01). Radiographically, there was improved apposition and nonsignificant resorption for the test group in ridge height and width, whereas statistically significant higher resorption was seen in the control group at 4 months. The application of the PDDM block demonstrated efficacy in maintaining the dimensions of the extraction socket when compared to A-PRF+ alone. This autologous and immune-free regenerative biomaterial is widely obtainable, offering a glimpse into the potential of next-generation biofuels for regeneration.

Research and development of demineralised dentin-derived collagen granule bone regeneration materials using animal teeth

The enamel that forms the outer layer of a tooth is the hardest substance in the human body and the structure of the teeth present an opportunity for investigation. For example, Dr Naoto Okubo, who has expertise in dentistry, is interested in the raw material from which the teeth are composed ‐ dentin. Dentin has a special structure known as â–˜ivory tubulesâ–™ that only exists in teeth and can be said to be a communicating porous structure. There is potential that it could be used in the development of new implantable biomaterials. Okuboâ–™s current research is exploring whether dentin can be used as a material for building bioregenerative scaffolds. He is based in the Faculty of Pharmaceutical sciences, Department of Molecular and Cellular Medicine, Hokkaido University, Japan, and is Project Leader of the Bovine Demineralized Dentin Matrix (B-DDM) projects. One of the reasons that dentin is suitable as a material for bioregenerative scaffolds is because the most important quality for bioregenerative scaffolds is that they do not interfere with the blood supply when they have been implanted. In addition, it has the strength needed to be used for bioregenerative scaffolds. In their work to use dentin and its tubule structure for the development of bioregenerative scaffolds Okubo and the team are using dentin in such a way that enables them to remove some or all the inorganic components at the same time as maintaining the tissue structure. This means the foundation of the scaffold is mainly composed of type 1 collagen, which has excellent blood permeability and high natural strength.

Effect of 38% Silver Diamine Fluoride on Salivary Matrix Metalloproteinase-9 Levels in Children with Early Childhood Caries: A Clinical Study.

Early childhood caries is a major oral health problem in most industrialized countries, affecting the overall quality of life of children. It is caused by the action of bacterial acids on the enamel surface thereby demineralizing it and progressively destroying the tooth. It presents initially as smooth-surface carious lesions affecting the primary maxillary incisors. With the advancement of the lesion, decay progresses further to involve other primary teeth as well and if not treated early, the caries may involve the pulp leading to irreversible pulpitis. Matrix metalloproteinases (MMPs) are a group of endopeptidases that degrade almost all the proteins of the extracellular matrix (ECM). Among the different types of MMP, MMP-9 (gelatinase B) is one of the chief MMPs responsible for the breakdown of the organic matrix. Traces of MMP-9 can be found in the human carious lesions, saliva, and gingival crevicular fluid. They are activated by the release of acids by cariogenic bacteria and once activated they are able to digest demineralized dentin matrix. Thus, host-derived MMPs, which are activated by bacterial acids have a crucial role in the destruction of dentine by caries. Thus, this study was undertaken to investigate the effect of 38% silver diamine fluoride (SDF) solution on MMP-9 levels. This clinical trial investigated the MMP-9 levels before and after the application of 38% SDF in children with early childhood caries. About 15 children were selected and were subjected to clinical and radiographic assessment before the commencement of the procedure. After the collection of saliva, the teeth with carious lesions were isolated and SDF was applied. Saliva samples were again collected after 1, 3, and 6 months postapplication of SDF. The collected saliva samples were then analyzed for their MMP-9 levels using a human salivary enzyme-linked immunosorbent assay (ELISA) kit. Finally, the data obtained were subjected to statistical analysis by repeated measures of analysis of variance (ANOVA). The MMP-9 levels were found to be gradually increasing postapplication of 38% SDF and were significantly higher after 6 months and the highest mean difference in the MMP-9 levels was observed between baseline and 6th-month follow-up. Also, no new carious lesion appeared in the teeth during the experimental time period of 6 months and the decayed, extraction needed, filled teeth (deft) scores remained the same. Bora P, Saxena A, Goswami M. Effect of 38% Silver Diamine Fluoride on Salivary Matrix Metalloproteinase-9 Levels in Children with Early Childhood Caries: A Clinical Study. Int J Clin Pediatr Dent 2023;16(S-1):S51-S56.

The Host Response to Autogenous, Allogeneic, and Xenogeneic Treated Dentin Matrix/Demineralized Dentin Matrix-Oriented Tissue Regeneration.

Dentin is a bone-like matrix that forms the bulk of the tooth. By fabricating dentin with protocols involving demineralization, sterilization, and preservation, treated dentin matrix (TDM)/demineralized dentin matrix (DDM) could be obtained, which is considered as a useful tool for bone and tooth-tissue regeneration. Non-negligible inflammatory and immune responses are reviewed in this article of autogenous, allogeneic, and xenogeneic TDM/DDM for the first time. Both autogenous and allogeneic TDM/DDM showed good biocompatibility in original and clinical studies, while a few cases reported the observation of inflammatory cells around tissue samples. As for xenogeneic TDM/DDM, multiple immune responses were revealed. Immune cells, including eosinocytes, macrophages, lymphocytes, mutinucleated giant cell, M1/M2 macrophages, and Th1-type CTL responses were involved. To avoid these adverse inflammatory responses caused by TDM/DDM implantation, some of the effective fabricating methods are discussed to reduce host immune responses to TDM/DDM.

The healing capacity and osteogenesis pattern of demineralized dentin matrix (DDM)-fibrin glue (FG) compound

Demineralized dentin matrix (DDM) is an osteoconductive and osteoinductive material that has been successfully used in sinus floor augmentation and alveolar ridge augmentation in clinical applications. It releases bone morphogenetic proteins (BMPs) and other growth factors, making DDM a suitable grafting material. However, the granular particle of DDM makes it difficult to anchor into the bone defect area. The aim of this study was to investigate the biological effects and osteoinductivity of the combination of DDM and Fibrin Glue (FG) at an optimal ratio on bone healing from a critical bone defect in an animal model. The mouse osteoblastic cell line (MC3T3-E1) was co-cultured with various ratios of DDM and FG to examine their effects on osteoblast proliferation and differentiation, as indicated by alkaline phosphatase (ALP) activity, osteocalcin (OC) production and mineralized nodules formation. The optimal ratio was then chosen for further study with a rabbit calvarial defective model, in which they were implanted with DDM or DDM-FG1 (1 g: 0.1 ml) and DDM-FG2 (1 g: 0.5 ml) compounds, or left blank for 2, 4, 8 and 12 weeks to investigate soft tissue and new bone regeneration. Micro-CT and histology analysis were used to evaluate the total grafting properties according to the different healing periods. The result from in vitro studies demonstrated that the ratio of 1:0.1 induced more ALP activity and mineralized nodules, while the ratio of 1: 0.5 (DDM-FG combined) induced more osteocalcin (OC) at specific time points. In the animal model, the 3D new bone volume in all DDM-FG treatment groups was significantly greater than that in the blank group at 2, 4, 8 and 12 weeks. Furthermore, the new bone volume was greater in DDM-FG2 when compared to the other groups during the early weeks of the healing period. In histological analysis, clusters of osteoblasts were formed adjacent to the DDM particles, and newly formed bone was observed in all groups, suggesting an osteoinductive property of DDM. Moreover, the greater new collagen synthesis observed at 4 weeks suggested that early bone healing was induced in the DDM-FG2 group. This study demonstrated that at an optimal ratio, the DDM-FG compound enhances osteogenic activities and bone regeneration.

Demineralized dentin matrix technique - a comparison of different demineralizing solutions.

This study aimed to evaluate the microstructure formed after the chemical treatment of teeth, for the development of autogenous grafts from the demineralized dentin matrix (DDM) technique, in order to identify the most efficient demineralizing solution. The specimens, originating from the root and coronal portion, were submitted to ultrasonic cleaning and drying in an oven for 1h at 100 ºC. Then, the density was determined by Archimedes' principle for each specimen, using distilled water as immersion liquid. The samples were separated into five groups: Control group: negative control, Distilled water;EDTA group: positive control, trisodium EDTA; NaOCl group: 2.5% sodium hypochlorite; HCl-0.6M group: 0.6M hydrochloric acid; and H2O2/H2SO4 group: hydrogen peroxide and sulfuric acid. Each specimen was immersed for 1h in the corresponding group descaling solution at 60 ºC. Subsequently, the mass loss and density of the treated specimens were determined by Archimedes' principle. Ultimately, the specimens of each group were characterized by microtomography, Scanning Electron Microscopy, and Energy Dispersive Spectrometry X-ray (SEM-EDS). The results demonstrated that the H2O2/H2SO4 solution allowed the formation of interconnected micropores, suggesting better pore structures for application in scaffolds, when compared to the other studied solutions.