Regenerative medicine: characterization of human bone matrix gelatin (BMG) and folded platelet-rich fibrin (F-PRF) membranes alone and in combination (sticky bone)

During the last two decades autologous platelet and leukocyte rich products (PRP; PRF), opened new perspectives in regenerative medicine. In particular regenerative dentistry played a pioneer role in the application of these products in bone regenerative cases. Many aspects of cytokines, such as, growth factor release, blood cell content and its characterization were reported, but some practical questions are still unanswered in the preparation of PRF membranes and sticky bones. A new folding technique was introduced that created a good quality, pliable, and strong F-PRF membrane with a dense fibrin network and more homogenous blood cell distribution. F-PRF produced a very promising sticky bone combined with human freeze-dried cortical bone matrix gelatin (BMG). There hasn’t been much focus on the quality and character of the applied bone and the optimal membrane/bone particle ratio has not been reported. A 0.125 g BMG/ml plasma (1 g/8 ml) seems like the ideal combination with maximal BMG adhesion capacity of the membrane. Particle distribution of BMG showed that 3/4 of the particles ranged between 300–1000 µ, the remnant 1/4 was smaller than 300 µ. The whole F-PRF membrane and its parts were compared with conventional A-PRF membrane concerning their resistance against proteolytic digestion. The F-PRF was superior to A-PRF, which dissolved within 4–5 days, while F-PRF was destroyed only after 11 days, so this provides a better chance for local bone morphogenesis. The F-PRF pieces had similar resistance to the whole intact one, so they can be ideal for surgical procedures without risk of fast disintegration.

Collagen membrane versus platelet rich fibrin membrane in bone graft healing: An experimental study in sheep.

Background and objectives: Guided bone regeneration is a term used to define the use of barri-er membranes to promote complete osteogenesis. The aim of study was to histologically com-pare the effect of platelet rich fibrin membrane and resorbable Collagen membrane on bone substitute healing. Methods: in this experimental study three sheep’s which their weighted between 60-70 kg were used. After intramuscular sedation and local anesthesia, eighteen defects were created about 8 mm in diameter and 5 mm in depth in the lower border of mandible. Six defects on each animal which three in right side and three in left side of the mandible. The defects were filled with Biphasic calcium phosphate bone substitute. The first defect was covered by platelet rich fibrin membrane, the second one covered by Collagen membrane, and third one was left uncovered. The animals were sacrificed at 2, 6, and 12 weeks. Results: The healing of the grafted defects was histologically studied in all groups, and there was non-significant difference between PRF membrane and collagen membrane in healing of bone substitute at 2, 6, and 12 weeks.There was significant deference between PRF membrane and collagen membrane at 6 weekregarding scaffold replacement with mature bone. Conclusion: The use of PRF membrane shows a good outcome as a low cost biological material capable of improving bone healing defects, grafted with bone substitute. Keywords: Platelet rich fibrin membrane, collagen membrane, bone graft, bone healing.

Study on repairing canine mandibular defect with porous Mg–Sr alloy combined with Mg–Sr alloy membrane

To discuss the feasibility of the application of porous Mg–Sr alloy combined with Mg–Sr alloy membrane in the repair of mandibular defects in dogs. The second and third mandibular premolars on both sides were extracted from six dogs. The model of mandible buccal fenestration bone defects were prepared after the sockets healed. Twelve bone defects were randomly divided into groups A and B, then Mg–Sr alloy was implanted in bone defects of group A and covered by Mg–Sr alloy membrane while Mg–Sr alloy was implanted in bone defects of group B and covered by mineralized collagen membrane. Bone defects observed on cone beam computed tomographic images and comparing the gray value of the two groups after 4, 8 and 12 weeks. After 12 weeks, the healing of bone defects were evaluated by gross observation, X-ray microscopes and histological observation of hard tissue. Bone defects in each group were repaired. At 8 and 12 weeks, the gray value of group A was higher than that of group B (P < 0.05). At 12 weeks, the bone volume fraction of group A was higher than that of group B (P < 0.05). The newly woven bone in group A is thick and arranged staggered, which was better than that of group B. Porous Mg–Sr alloy combined with Mg–Sr alloy membrane could further promote the repair of mandibular defects, and obtain good osteogenic effect.

Clinical and Radiographic Evaluation of Regenerative Potential of GTR Membrane (Biomesh®) along with Alloplastic Bone Graft (Biograft®) in the Treatment of Periodontal Intrabony Defects

ABSTRACT Background and objectives The primary goal of periodontal therapy is to restore the tooth supporting tissues lost due to periodontal disease. The aim of the present study was to compare the efficacy of combination of GTR membrane and alloplastc bone graft with open flap debridement (OFD) in treatment of periodontal intrabony defects. Methods Twenty paired intrabony defects were surgically treated using split mouth design. The defects were randomly assigned to treatment with OFD, GTR membrane + bone graft (test) or OFD alone (control). The clinical efficacy of two treatment modalities was evaluated at 6 months postoperatively by clinical, radiographical parameters. The measurements included probing pocket depth (PD), clinical attachment level (CAL), gingival recession (GR), bone fill (BF), bone density (BD). Results The mean reduction in PD at 0 to 6 months was 3.20 ± 0.82 mm and CAL gain of 3.10 ± 1.51 mm occurred in the GTR membrane + bone graft (test) group; corresponding values for OFD (control) were 2.10 ± 0.63 mm and 1.90 ± 0.57 mm. Similar pattern of improvement was observed when radiographically postoperative evaluation was made. All improvement in different parameters was statistically significant (p < 0.01). Conclusion Treatment with a combination of collagen membrane and bone graft led to a significantly more favorable clinical outcome in intrabony defects as compared to open flap debridement alone. How to cite this article Mopur JM, Devi TR, Ali SM, Srinivasa TS, Gopinath V, Salam ART. Clinical and Radiographic Evaluation of Regenerative Potential of GTR Membrane (Biomesh®) along with Alloplastic Bone Graft (Biograft®) in the Treatment of Periodontal Intrabony Defects. J Contemp Dent Pract 2013;14(3):434-439.

Bone Regeneration Materials

Biomaterials Center is composed of five groups and collaborate each other to examine interdisciplinary fields of biomaterials. In the ceramics-based biomaterials research, we have been developing three novel bone regeneration materials, i.e., high-porosity hydroxyapatite (HAp) ceramics with high-strength, guided bone regeneration (GBR) membranes and bone-like nanocomposite composed of HAp and collagen. The GBR membrane composed of β-tricalcium phosphate and biodegradable copolymer of lactide, glycolide and ε-caprolactone has thermoplastic, pH auto-adjustment and enough mechanical property to protect an invasion of surrounding tissues. With the membrane, bone defect up to 20 × 10 × 10 mm3 in length in mandibles and segmental bone defect up to 20 mm in length in tibiae of beagles are regenerated without any additional bone fillers or cell transplantations. The bone-like nanocomposite is synthesized by a co-precipitation of HAp and collagen via their self-organization. The dense composite has a half to quarter mechanical strength (40 MPa) to cortical bone and the porous one demonstrates sponge-like viscoelasticity. The composites implanted into bone are incorporated into bone remodeling metabolism like as autogenous bone graft, i.e., they are resorbed by osteolasts followed by osteogenesis by osteoblasts.