Graft Material Research Articles

Unleashing innovation: 3D-printed biomaterials in bone tissue engineering for repairing femur and tibial defects in animal models - a systematic review and meta-analysis.

3D-printed scaffolds have emerged as an alternative for addressing the current limitations encountered in bone reconstruction. This study aimed to systematically review the feasibility of using 3D bio-printed scaffolds as a material for bone grafting in animal models, focusing on femoral and tibial defects. The primary objective of this study was to evaluate the efficacy, safety, and overall impact of these scaffolds on bone regeneration. Electronic databases were searched using specific search terms from January 2013 to October 2023, and 37 relevant studies were finally included and reviewed. We documented the type of scaffold generated using the 3D printed techniques, detailing its characterization and rheological properties including porosity, compressive strength, shrinkage, elastic modulus, and other relevant factors. Before incorporating them into the meta-analysis, an additional inclusion criterion was applied where the regenerated bone area (BA), bone volume (BV), bone volume per total volume (BV/TV), trabecular thickness (Tb. Th.), trabecular number (Tb. N.), and trabecular separation (Tb. S.) were collected and analyzed statistically. 3D bio-printed ceramic-based composite scaffolds exhibited the highest capacity for bone tissue regeneration (BTR) regarding BV/TV of femoral and tibial defects of animal models. The ideal structure of the printed scaffolds displayed optimal results with a total porosity >50% with a pore size ranging between 300- and 400µM. Moreover, integrating additional features and engineered macro-channels within these scaffolds notably enhanced BTR capacity, especially observed at extended time points. In conclusion, 3D-printed composite scaffolds have shown promise as an alternative for addressing bone defects.

Comparison of Khoury's Bone Shell Technique vs Titanium-reinforced Polytetrafluoroethylene Membrane for 3D-bone Augmentation in Atrophic Posterior Mandible: A Randomized Clinical Trial.

This study was designed to compare between the use of Khoury's bone shell technique vs titanium-reinforced PTFE membrane for 3D-ridge augmentation of atrophic posterior mandible. Sixteen patients were equally and randomly assigned to either the Khoury or PTFE group. In Khoury group, a mandibular bone block was harvested, split and then fixed to augment the mandibular defect using osteosynthesis screws. In PTFE group, augmentation was achieved using Titanium-reinforced PTFE membranes fixed with bone tacks/screws. A mixture of autogenous and xenogenic graft material at a 1:1 ratio was used in both groups. Vertical and horizontal bone gain were obtained using cone-beam computed tomography (CBCT). Preoperative dimensions were compared with the final dimensions obtained 6 months postoperatively. No significant complications or neurosensory dysfunction were encountered. A solitary patient in the Khoury group experienced limited wound dehiscence, which was treated conservatively. For both groups, there were no significant differences between preoperative and postoperative vertical (p = 0.849 and 0.569) and horizontal (p = 0.778 and 0.367) dimensions. No significant differences exist between the augmentation dimension which can be obtained using either Khoury of Ti-PTFE membranes. Both approaches are delicate and necessitate surgical expertise and experience. Both techniques can be used to achieve predictable augmentation results with a low rate of complications. How to cite this article: Shaker AES, Salem AS, El-Farag SAA, et al. Comparison of Khoury's Bone Shell Technique vs Titanium-reinforced Polytetrafluoroethylene Membrane for 3D-bone Augmentation in Atrophic Posterior Mandible: A Randomized Clinical Trial. J Contemp Dent Pract 2024;25(6):518-526.

Polycaprolactone Hybrid Scaffold Loaded With N,O-Carboxymethyl Chitosan/Aldehyde Hyaluronic Acid/Hydroxyapatite Hydrogel for Bone Regeneration.

Hydrogels have emerged as potential materials for bone grafting, thanks to their biocompatibility, biodegradation, and flexibility in filling irregular bone defects. In this study, we fabricated a novel NAH hydrogel system, composed of N,O-carboxymethyl chitosan (NOCC), aldehyde hyaluronic acid (AHA), and hydroxyapatite (HAp). To improve the mechanical strength of the fabricated hydrogel, a porous polycaprolactone (PCL) matrix was synthesized and used as a three-dimensional (3D) support template for NAH hydrogel loading, forming a novel PCL/NAH hybrid scaffold. A mixture of monosodium glutamate (M) and sucrose (S) at varied weight ratios (5M:5S, 7M:3S, and 9M:1S) was used for the fabrication of 3D PCL matrices. The morphology, interconnectivity, and water resistance of the porous PCL scaffolds were investigated for optimal hydrogel loading efficiency. The results demonstrated that PCL scaffolds with porogen ratios of 7M:3S and 9M:1S possessed better interconnectivity than 5M:5S ratio. The compressive strength of the PCL/NAH hybrid scaffolds with 9M:1S (561.6 ± 6.1 kPa) and 7M:3S (623.8 ± 6.8 kPa) ratios are similar to cancellous bone and all hybrid scaffolds were biocompatible. Rabbit models with tibial defects were implanted with the PCL/NAH scaffolds to assess the wound healing capability. The results suggest that the PCL/NAH hybrid scaffolds, specifically those with porogen ratio of 7M:3S, exhibit promising bone healing effects.

Clinical practice guideline for autologous bone grafting in China (2024 edition)

Autogenous bone has always been the gold-standard bone graft material. As such, it is the primary choice for bony grafts. Autogenous bone grafting has been performed for hundreds of years, and more than 2 million cases of autogenous bone transplantation are performed each year worldwide. It has become the most commonly used surgical method in orthopedics. Numerous studies have suggested methods to select the appropriate donor area, standardize the surgical procedure, and reduce donor site complications, but clinical standards and guidelines remain to be established. To better guide the clinical practice of physicians in China, the Trauma Orthopedic Branch of the Chinese Orthopedic Association, the External Fixation and Limb Reconstruction Branch of the Chinese Orthopedic Association, and the Microsurgery Branch of the Beijing Orthopedic Association developed the "Clinical practice guideline for autogenous bone grafting in China (2024 edition)" based on current medical evidence. This guideline systematically evaluates recent domestically and internationally published literature and medical research evidence in the field of autologous bone grafting in the Chinese population. The guideline was produced with the aim of standardizing the indications and techniques for autogenous bone transplantation, as well as preventing complications at the harvesting site of autologous bone, in the Chinese population.

Advantages and Disadvantages of Reconstructive and Preservation Rhinoplasty: Surgical Techniques, Outcomes, and Future Directions.

Reconstructive rhinoplasty, a specialized surgical procedure, aims to restore both the form and function of the nose, particularly after trauma, congenital defects, or prior surgeries. This review evaluates the advantages and disadvantages of various surgical techniques used in reconstructive and preservation rhinoplasty. The study focuses on the outcomes of commonly employed methods such as cartilage grafting, flap techniques, and alloplastic materials, assessing both functional and aesthetic results. Recent advancements, including 3D imaging, tissue engineering, and artificial intelligence, are discussed as potential future directions that could enhance surgical precision, safety, and patient care. The review systematically examines clinical studies from the past decade, highlighting the evolving landscape of rhinoplasty and its impact on patient outcomes.

Comparing the Immune Response to PEEK as an Implant Material with and without P-15 Peptide as Bone Graft Material in a Rabbit Long Bone Model.

P-15 is a 15-amino-acid-long biomimetic peptide widely demonstrated to enhance osteogenesis in vivo. Despite the prevalence of polyether-ether-ketone (PEEK) in interbody device manufacturing, a growing body of evidence suggests it may produce an unfavorable immune response. The purpose of this preliminary study was to characterize the immune response and new bone growth surrounding PEEK implants with and without a P-15 peptide-based osteobiologic. A bilateral femoral defect model was conducted using New Zealand white rabbits. A total of 17 test subjects received one implant in each distal femur, either with or without bone graft material. Animals were allowed to survive to 4 or 8 weeks, at which time the femurs were collected and subjected to micro-computer tomography (microCT) or cytokine analysis. MicroCT analysis included the quantification of bone growth and density surrounding each implant. The cytokine analysis of periprosthetic tissue homogenates included the quantification of interleukins (ILs) and TNF-α expression via ELISA kits. Improvements in bone volume were observed in the P-15 cohort for the regions of interest, 500-136 and 136-0 µm from the implant surface, at 8 weeks post-op. Concentrations of IL-1β, IL-4, and IL-6 cytokines were significantly higher in the P-15 cohort compared to the PEEK cohort at the 4-week timepoint. Significant reductions in the concentrations of IL-4 and IL-6 cytokines from the 4- to 8-week cohort were observed in the P-15 cohort only. The P-15 peptide has the potential to modulate the immune response to implanted materials. We observed improvements in bone growth and a more active micro-environment in the P-15 cohort relative to the PEEK control. This may indicate an earlier transition from the inflammatory to remodeling phase of healing.

Investigating the Promising P28 Peptide-Loaded Chitosan/Ceramic Bone Scaffolds for Bone Regeneration.

Bone has the ability to heal itself; however, bone defects fail to heal once the damage exceeds a critical size. Bone regeneration remains a significant clinical challenge, with autograft considered the ideal bone graft material due to its sufficient porosity, osteogenic cells, and biological growth factors. However, limitations to bone grafting, such as limited bone stock and high resorption rates, have led to a great deal of research into developing bone graft substitutes. The P28 peptide is a small molecule bioactive biomimetic alternative to mimic the bone morphogenetic protein 2 (BMP-2). In this study, we investigated the potential of P28-loaded hybrid scaffolds to mimic the natural bone structure for enhancing the bone regeneration process. We hypothesized that the peptide-loaded scaffolds and nude scaffolds both have the potential to promote bone healing, and the bone healing process is accelerated by the release of the peptide. To verify our hypothesis, C2C12 cells were evaluated for the presence of calcium deposits by histological stain at 7 and 14 days in cultures with hybrid scaffolds. Total RNA was isolated from C2C12 cells cultured with hybrid scaffolds for 7 and 14 days to assess osteoblast differentiation. The project findings demonstrated that the hybrid scaffold could enhance osteoblast differentiation and significantly improve the therapeutic effects of the scaffold in bone regeneration.

The efficiency of two different synthetic bone graft materials on alveolar ridge preservation after tooth extraction: a split-mouth study

BackgroundAlveolar Bone loss occurs frequently during the first six months after tooth extraction. Various studies have proposed different methods to reduce as much as possible the atrophy of the alveolar ridge after tooth extraction. Filling the socket with biomaterials after extraction can reduce the resorption of the alveolar ridge. We compared the height of the alveolar process at the mesial and distal aspects of the extraction site and the resorption rate was calculated after the application of HA/β-TCP or synthetic co-polymer polyglycolic - polylactic acid PLGA mixed with blood to prevent socket resorption immediately and after tooth extraction.MethodsThe study was conducted on 24 extraction sockets of impacted mandibular third molars bilaterally, vertically, and completely covered, with a thin bony layer. HA/β-TCP was inserted into 12 of the dental sockets immediately after extraction, and the synthetic polymer PLGA was inserted into 12 of the dental sockets. All sockets were covered completely with a full-thickness envelope flap. Follow-up was performed for one year after extraction, using radiographs and stents for the vertical alveolar ridge measurements.ResultsThe mean resorption rate in the HA/β-TCP and PLGA groups was ± 1.23 mm and ± 0.1 mm, respectively. A minimal alveolar bone height reduction of HA/β-TCP was observed after 9 months, the reduction showed a slight decrease to 0.93 mm, while this rate was 0.04 mm after 9 months in the PLGA group. Moreover, the bone height was maintained after three months, indicating a good HA/β-TCP graft performance in preserving alveolar bone (1.04 mm) while this rate was (0.04 mm) for PLGA.ConclusionThe PLGA graft demonstrated adequate safety and efficacy in dental socket preservation following tooth extraction. However, HA/β-TCP causes greater resorption at augmented sites than PLGA, which clinicians should consider during treatment planning.

Biologic grafts for pelvic organ prolapse repairs: what have we learned in the last 20 years?

The ideal graft material for the augmentation of pelvic organ prolapse (POP) has yet to be discovered. While synthetic mesh offers durable repairs this can be at the expense of mesh complications. Biologic grafts have been considered an alternative. This chapter reviews biologic graft materials as applied to POP surgery. The heterogeneity of available graft materials and definitions of success in POP literature make comparisons difficult. There may be utility in the augmentation of apical prolapse with autologous grafts. There is also modest evidence to support anterior wall augmentation with biologic grafts. However, a 2024 Cochrane review concluded there is not enough evidence to support routine use of grafts for transvaginal repairs. Biologic grafts can be considered in certain cases. There continues to be a need for finding the ideal "graft-patient" combination. The field particularly needs more robust research in the recurrent POP patient population.

Effectiveness of the Association of Fibrin Scaffolds, Nanohydroxyapatite, and Photobiomodulation with Simultaneous Low-Level Red and Infrared Lasers in Bone Repair.

Biomaterials and biopharmaceuticals for correcting large bone defects are a potential area of translational science. A new bioproduct, purified from snake venom and fibrinogen from buffalo blood, aroused interest in the repair of venous ulcers. Expanding potential uses, it has also been used to form biocomplexes in combination with bone grafts, associated with physical therapies or used alone. The aim of this preclinical study was to evaluate low-level laser photobiomodulation (PBM) in critical defects in the calvaria of rats filled with nanohydroxyapatite (NH) associated with the heterologous fibrin biopolymer (HFB). Sixty animals were used, divided into six groups (n = 10 each): G1 (NH); G2 (HFB); G3 (NH + HFB); G4 (NH + PBM); G5 (HFB + PBM); G6 (NH + HFB + PBM). PBM simultaneously used red (R) and infrared (IR) light emission, applied intraoperatively and twice a week, until the end of the experiment at 42 days. Microtomography, bone formation can be seen initially at the margins of the defect, more evident in G5. Microscopically, bone formation demonstrated immature and disorganized trabeculation at 14 days, with remnants of grafting materials. At 42 days, the percentage of new bone formed was higher in all groups, especially in G5 (HFB, 45.4 ± 3.82), with collagen fibers at a higher degree of maturation and yellowish-green color in the birefringence analysis with Picrosirius-red. Therefore, it is concluded that the HFB + PBM combination showed greater effectiveness in the repair process and presents potential for future clinical studies.

Outcomes of Xenograft with Platelet-rich Fibrin versus Autogenous Bone in Alveolar Cleft Grafting.

The use of a suitable graft material helps with sufficient osseointegration. The aim of this study was to compare the clinical and radiographic outcomes of two types of alveolar bone graft materials, xenografts with platelet-rich fibrin (PRF) and autogenous grafts, in patients with alveolar clefts. Thirty-six patients with alveolar clefts were enrolled in this study. Those patients were randomly divided into two groups: group A, where the autogenous iliac bone graft was used to fill the alveolar defect, and group B, where the xenograft with PRF was used to fill the alveolar defect. After 6 months of grafting, patients were assessed in terms of pain, duration of hospital stay, and donor site morbidity associated with iliac crest harvesting, while bone formation was evaluated radiographically using cone beam computed tomography. The results showed no statistical differences as regards baseline and perioperative data. Operative duration was significantly lower among xenograft with PRF patients. Both groups had comparable postoperative success scores, and total failure was reported in a total of three patients (one patient in group A and two patients in group B). With no potential donor site morbidities, xenograft with PRF is an equivalent bone transplant replacement to the autologous iliac bone graft. Additionally, it is associated with a significant success rate, and a significant decrease in operative time and hospital stay. Many future studies are warranted to draw firm conclusions.

Efficacy of using autologous cells with graft substitutes for spinal fusion surgery: A systematic review and meta-analysis of clinical outcomes and imaging features.

Over the past several decades, there has been a notable increase in the total number of spinal fusion procedures worldwide. Advanced spinal fusion techniques, surgical approaches, and new alternatives in grafting materials and implants, as well as autologous cellular therapies, have been widely employed for treating spinal diseases. While the potential of cellular therapies to yield better clinical results is appealing, supportive data are needed to confirm this claim. This meta-analysis aims to compare the radiographic and clinical outcomes between graft substitutes with autologous cell therapies and graft substitutes alone. PubMed, Scopus, Web of Science, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials were searched for studies comparing graft substitutes with autologous cell therapies and graft substitutes alone up to February 2024. The risk of bias of the included studies was evaluated using the Downs and Black checklist. The following outcomes were extracted for comparison: fusion success, complications/adverse events, Visual Analog Scale (VAS) score, and Oswestry Disability Index (ODI) score. Thirteen studies involving 836 patients were included, with 7 studies considered for the meta-analysis. Results indicated that the use of graft substitutes with autologous cell therapies demonstrated higher fusion success rates at 3, 6, and 12 months, lower VAS score at 6 months, and lower ODI score at 3, 6, and 12 months. The complication rate was similar between graft substitutes with autologous cell therapies and graft substitutes alone. Although the current literature remains limited, this meta-analysis suggests that the incorporation of cellular therapies such as bone marrow and platelet derivatives with graft substitutes is associated with a higher fusion rate and significant improvements in functional status and pain following spinal fusion. Future well-designed randomized clinical trials are needed to definitively assess the clinical effectiveness of cellular therapies in spinal fusion.

Investigation of the extent of post-extraction bone contraction and remodeling after 4 months. A prospective pilot study

ObjectivesTo investigate the correlation between the serum levels of 25(OH)D and the resorption of the alveolar bone walls and regeneration of the alveolar space after tooth extraction. Methods14 adults in need of extraction of hopeless teeth were enrolled. An intraoral digital impression was performed, and each patient was tested to assess serum vitamin D levels. Subsequently, extraction of teeth and contextual guided bone regeneration was performed using porcine origin graft material and a resorbable collagen membrane to covert the defect. After 4 months, an impression was taken, and the model was scanned using a professional scanner for lab. At the same time, a cone beam computed tomography was performed to plan implant insertion through fully digital computer guided surgery. Bone was collected to perform histological and histomorphometric analysis. Pre and postoperative scans were compared using a specific software to estimate the volumetric changes. Tests were applied to investigate the relationship between the different predictor variables and the outcome variables. Results14 patients were divided in 3 groups depending on the serum Vit-D levels, identifying three ranges corresponding to low (lower than 20), medium (between 20 and 30), and optimal vitamin D levels (higher than 30). Volumetric contraction after extraction was observed for all patients, without any significant difference between the groups. Focusing on the post-extraction regeneration, patients belonging to the group with lower levels of Vit-D displayed lower and more disorganized levels of bone. Immunohistochemistry analysis showed that Col1A1 and Osteocalcin had no physiological alteration. Osteopontin could be identified near the external surface of bone tissue granules. Runx2 signals were detected near the margins of bone trabeculae. ConclusionsSerum vit-D levels do not appear to influence the extent of post-extraction bone contraction; on the contrary, they seem to influence the post-extraction regeneration. Clinical SignificanceVit D serum levels may influence the regenerative aspect during post-extraction turn-over. This might suggest controlling and (in case of low levels) recommend Vit D supplement in the patient diet in case of extraction.

Maxillary Sinus Augmentation with Autogenous Tooth Grafting Material: A Systematic Review.

The aim of this systematic review was to determine whether autogenous tooth grafting material (ATGM) is as safe and effective as other bone substitutes used for maxillary sinus augmentation procedures, evaluating histomorphometric and/or histological data, implant primary stability, associated complications and radiographic bone height measurements. An automated electronic search was conducted using four databases (Medline/PubMed, Scopus, Web of Science and Cochrane Library), supplemented by a manual search, to identify clinical human studies using particulate ATGM for the aforementioned procedure. The included studies had a sample size of at least four patients and were published before 31st July 2024. The Newcastle-Ottawa scale (NOS) and Joanna Briggs Institute (JBI) Critical Appraisal Checklist were used to assess the risk of bias in cohort studies and case series, respectively. Seven studies were included in the descriptive analysis, obtaining 128 participants (46.8% only treated with ATGM) and 192 placed implants. Due to the heterogeneity of the studies, meta-analysis could not be performed. The authors concluded that ATGM appears to be a feasible and safe alternative for maxillary sinus augmentation procedures. These results should be interpreted with caution due to the limited amount of scientific evidence on this topic and the heterogeneity between the included studies.

Lateral Alveolar Ridge Augmentation with Autogenous Tooth Roots and Staged Implant Placement-5-Year Follow-Up Case Series.

Background/Objectives: Alveolar bone augmentation before implant placement is a safe and effective treatment option for the reconstruction of a deficient alveolar ridge. According to recent research, permanent teeth have been used as bone graft materials, with studies confirming their clinical and histological results. This study aimed to evaluate the efficacy of alveolar ridge augmentation with autogenous tooth roots and staged implant placement, and peri-implant tissue stability in augmented sites. Methods: A total of 20 augmentations with autogenous tooth roots on mandibular alveolar ridges in 15 patients were performed. After 6 months, the ridge width (RWa) and ridge width gain (RWg) were measured. Titanium dental implants were placed in grafted sites and loaded 10 weeks after placement. Clinical parameters (bleeding on probing-BOP; probing depth-PD; mucosal recession-MR; and clinical attachment level-CAL) were assessed 2 months (T1), 3 years (T2), and 5 years (T3) after implant loading. Results: The mean RWa was 6.71 ± 0.74 mm, and the RWg was 3.15 ± 0.54 mm, respectively. No statistically significant differences were observed for clinical parameters (BOP, PD, MR, and CAL) among different time points (p > 0.05). Conclusions: Autogenous tooth roots represent a viable solution for alveolar ridge augmentation and implant placement, providing a stable environment for peri implant tissues.

Comparison of Biomechanical and Microstructural Properties of Aortic Graft Materials in Aortic Repair Surgeries.

Mechanical mismatch between native aortas and aortic grafts can induce graft failure. This study aims to compare the mechanical and microstructural properties of different graft materials used in aortic repair surgeries with those of normal and dissected human ascending aortas. Five types of materials including normal aorta (n = 10), dissected aorta (n = 6), human pericardium (n = 8), bovine pericardium (n = 8) and Dacron graft (n = 5) were collected to perform uniaxial tensile testing to determine their material stiffness, and ultimate strength/stretch. The elastin and collagen contents in four tissue groups except for Dacron were quantified by histological examinations, while the material ultrastructure of five material groups was visualized by scanning electron microscope. Statistical results showed that three graft materials including Dacron, human pericardium and bovine pericardium had significantly higher ultimate strength and stiffness than both normal and dissected aortas. Human and bovine pericardia had significantly lower ultimate stretch than native aortas. Histological examinations revealed that normal and diseased aortic tissues had a significantly higher content of elastic fiber than two pericardial tissues, but less collagen fiber content. All four tissue groups exhibited lamellar fiber ultrastructure, with aortic tissues possessing thinner lamella. Dacron was composed of densely coalesced polyethylene terephthalate fibers in thick bundles. Aortic graft materials with denser fiber ultrastructure and/or higher content of collagen fiber than native aortic tissues, exhibited higher ultimate strength and stiffness. This information provides a basis to understand the mechanical failure of aortic grafts, and inspire the design of biomimetic aortic grafts.

Improving Biological Performance of 3D-Printed Scaffolds with Garlic-Extract Nanoemulsions.

Complex bone diseases such as osteomyelitis, osteosarcoma, and osteoporosis often cause critical-size bone defects that the body cannot self-repair and require an advanced bone graft material to repair. We have fabricated 3D-printed tricalcium phosphate bone scaffolds functionalized with garlic extract (GE). GE was encapsulated in a nanoemulsion (GE-NE) to enhance bioavailability and stability. GE-NE showed ∼73% drug encapsulation efficiency, with an average particle size of 158 nm and a zeta potential of -14.2 mV. Release of GE-NEs from the scaffold displayed a controlled and biphasic release profile at both acidic and physiological mediums. Results from the osteosarcoma study show that GE-NE demonstrated ∼88% reduction in cancer cell growth while exhibiting no cytotoxicity toward bone-forming cells. Interaction for the functionalized scaffold with Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa showed a substantial reduction in bacteria growth by more than 90% compared to the unfunctionalized scaffold. These findings demonstrate the potential of GE-NEs-treated porous scaffolds to treat bone-related diseases, particularly for non-load bearing applications.

Effect of vascularized jejunal conduit flap on peripheral nerve regeneration in rats.

In the literature, almost all of the nerve conduits proposed for obtaining better nerve recovery were applied as graft materials. In this study, we aimed to propose a new nerve conduit model with a flap pattern and evaluate the effect of a pedicled vascularized jejunal flap on nerve regeneration after wrapping it around a sciatic nerve. A total of 90 Wistar albino rats were randomly divided into nine groups with 10 rats in each. The first three groups constituted the control groups, whereas Groups 4-6 were the jejunum conduit (JC)-applied groups. A mucosa-resected JC (MRJC) was applied in Groups 7 and 8. Epineurial neurorrhaphy was performed in Groups 1, 4, and 7; repair with a nerve graft was applied in Groups 2, 5, and 8; and a 1-cm-long nerve defect was created in Groups 3, 6, and 9. After 2 months of follow-up, nerve regeneration was assessed by statistical analyses of the Sciatic Functional Index (SFI) and histopathological evaluation. The MRJC groups had significantly better results in terms of SFI (p = 0.005). Statistical differences in axonal degeneration, axonal density, myelination, and disorganization were found between all control groups and MRJC groups (p = 0.022, p = 0.001, p = 0.001, and p = 0.039, respectively). In this study, the feasibility of wrapping around the nerve repair zones of pedicled autologous flaps designed in a tubular fashion was observed in a small rat model. The findings must be further validated with larger animals before clinical testing.

Advances in autogenous dentin matrix graft as a promising biomaterial for guided bone regeneration in maxillofacial region: A review.

Autogenous dentin matrix (ADM), derived from a patient's extracted tooth, can be repurposed as an autologous grafting material in reconstructive dentistry. Extracted teeth provide a source for ADM, which distinguishes itself with its low rejection rate, osteoinductive capabilities and ease of preparation. Consequently, it presents a viable alternative to autogenous bone. Animal studies have substantiated its effective osteoinductive properties, while its clinical applications encompass post-extraction site preservation, maxillary sinus floor augmentation, and guided bone tissue regeneration. Nevertheless, the long-term efficacy of ADM applied in bone regeneration remains underexplored and there is a lack of standardization in the preparation processes. This paper comprehensively explores the composition, mechanisms underlying osteoinductivity, preparation methods, and clinical applications of ADM with the aim of establishing a fundamental reference for future studies on this subject.

Hydrogel Use in Osteonecrosis of the Femoral Head.

Osteonecrosis of the femoral head (ONFH) is a vascular disease of unknown etiology and can be categorized mainly into two types: non-traumatic and traumatic ONFH. Thus, understanding osteogenic-angiogenic coupling is of prime importance in finding a solution for the treatment of ONFH. Hydrogels are biomaterials that are similar to the extracellular matrix (ECM). As they are able to mimic real tissue, they meet one of the most important rules in tissue engineering. In ONFH studies, hydrogels have recently become popular because of their ability to retain water and their adjustable properties, injectability, and mimicry of natural ECM. Because bone regeneration and graft materials are very broad areas of research and ONFH is a complex situation including bone and vascular systems, and there is no settled treatment strategy for ONFH worldwide, in this review paper, we followed a top-down approach by reviewing (1) bone and bone grafting, (2) hydrogels, (3) vascular systems, and (4) ONFH and hydrogel use in ONFH with studies in the literature which show promising results in limited clinical studies. The aim of this review paper is to provide the reader with general information on every aspect of ONFH and to focus on the hydrogel used in ONFH.