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CURATOR
A pinboard by
Ghada Adayil

I am a master degree candidate at Faculty of Dentistry-Cairo University,Periodontist and implantologist.

PINBOARD SUMMARY

Bone is a specialized mineralized connective tissue that consists of specialized cell types including osteoblasts, osteoclasts and osteocytes and extracellular matrix. Physiologic bone remodeling consists of two main phases; the bone formation and resorption.

6 ITEMS PINNED

Cryopreservation of autologous bone grafts: an experimental study on a sheep animal model.

Abstract: A sheep animal model was used to investigate the clinical behavior of autologous bone transplants after cryopreservation. The aim of the present study was to compare fresh, cryopreserved and deep-frozen bone transplants in terms of their osseointegration. We used a serum-free cryopreservation protocol with DMSO as cryoprotectant for the bone transplants, which were harvested from the iliac crest of the sheep. The bicortical iliac bone grafts were either cryopreserved or immediately frozen to -80 degrees C for 4 weeks. Four, 8, 12 and 16 weeks after the autologous transplantation of the cryopreserved, fresh or deep-frozen bone transplants to the contralateral iliac crest, the animals were sacrificed and the bone specimens were evaluated clinically, by staining for hematoxylin/eosin and for tartrate-resistant acid phosphatase, by quantified computed tomography, immunohistochemistry (Ki67) and polychrome sequential labeling. The best results were obtained for the fresh specimens with 83% bone healing compared with 75% (cryopreserved bone) and 50% (deep frozen bone). All parameters indicate that bone formation and remodeling processes take place in fresh and cryopreserved transplants. The deep-frozen specimens displayed no fluorochrome uptake in the sequential labeling. These findings indicate that osseointegration of the fresh transplants was the most successful and that osteogenic effects in fresh and cryopreserved transplants are located in the surface area, whereas only the osteoconductive effects are important in the center of the transplants. Thus, cryopreservation is a useful method for the clinical routine because it keeps the osteogenic cells viable, making it superior to deep freezing of abundant bone.

Pub.: 07 Jan '10, Pinned: 25 Aug '17

Radiographic and histological evaluation of ectopic application of deproteinized bovine bone matrix

Abstract: Rodrigo Carlos da Silva, Viviane Rozeira Crivellaro, Allan Fernando Giovanini, Rafaela Scariot, Carla Castiglia Gonzaga, João César Zielak Annals of Maxillofacial Surgery 2016 6(1):9-14 Objective: To evaluate, through radiographic and histological analysis, the tissue reaction induced by a biomaterial based on deproteinized bovine bone matrix (DBBM) in the muscle of sheep. sMaterials and Methods: Sixteen sheep were used. The animals underwent surgery to insert polyethylene tubes containing the biomaterial in the muscle of the lower back (ectopic site) and were euthanized after 3 and 6 months. Each sheep received three tubes: Group 1 - sham group (negative control - tube without biomaterial), Group 2 - particulate autogenous bone (positive control), and Group 3 - DBBM biomaterial (GenOx Inorg). The material removed was evaluated by radiographic, macroscopic, and microscopic analysis, descriptively. Results: Macroscopic analysis showed that Group 3 had a greater tissue volume maintenance. Microscopic analysis indicated that Group 1 had a higher concentration of dense, thin collagen fibers (3 and 6 months); in Group 2, there was a decrease in the inflammatory process and the deposition of dense, thin collagen fibers (3 and 6 months); in Group 3, the presence of a dense connective tissue was noted, in which the DBBM particles (3 months) were found. On the periphery of these particles, a deposition of basophilic material was found, indicating the formation of mineral particles and the formation of tissues with osteoid characteristics (6 months). Conclusion: Based on the results obtained, it can be concluded that the biomaterial based on DBBM led to the formation of tissue with similar characteristics to an osteoid matrix in a postoperative period of 6 months. However, none of the groups evaluated showed ectopic bone neoformation.

Pub.: 12 Jul '16, Pinned: 25 Aug '17

Influence of Healing Period Upon Bone Turn Over on Maxillary Sinus Floor Augmentation Grafted Solely with Deproteinized Bovine Bone Mineral: A Prospective Human Histological and Clinical Trial

Abstract: To investigate the influence of maturation timing upon histological, histomorphometric and clinical outcomes when deproteinized bovine bone mineral (DBBM) was used as a sole biomaterial for staged maxillary sinus floor augmentation (MSFA).Patients with a posterior edentulous maxillary situation and a vertical bone height ≤ 4 mm were included in this study. A staged MSFA was carried out. After MSFA with DBBM as a sole grafting material, biopsy cores were harvested with simultaneous implant placement followed by a healing period of 5, 8, and 11 months, respectively. Micro-CT, histologic and histomorphometric analyses were performed.Forty-one patients were enrolled and 38 bone core biopsies were harvested. Significantly greater BV/TV was observed between 5- and 8-month healing from micro-CT analysis. Histomorphometric analyses showed the ratio of mineralized newly formed bone increased slightly from 5 to 11 months; however, no statistically significant difference was reached (p = .409). Residual bone substitute decreased from 37.3 ± 5.04% to 20.6 ± 7.45%, achieving a statistical significant difference from of 5 up to 11 months (p < .01). Moreover, no implant failure, biological or technical complication occurred after 12-month follow-up of functional loading.DBBM utilized as sole grafting material in staged MSFA demonstrated to be clinically effective regardless of the healing period. Histomorphometrical and micro-CT assessments revealed that at later stages of healing (8 and 11 months) there is a higher proportion of newly-bone formation compared to earlier stages (5 months). Moreover, the longer the maturation period, the substantially lesser remaining biomaterial could be expected. Even though, these facts did not seem to negatively impact on the implant prognosis 1-year after loading.

Pub.: 16 Nov '16, Pinned: 25 Aug '17