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Purpose: The objective of this pilot study was to histologically evaluate bone regeneration using a self-assembling peptide hydrogel scaffold with recombinant human bone morphogenetic protein-2 (rhBMP-2) in a rabbit calvaria model.
Materials and Methods: Five adult New Zealand White rabbits were used for the study. Each received four titanium cylinders, which were placed into perforated slits made in the outer cortical bone of the calvaria. The cylinders were filled with the following test materials: (1) unfilled control; (2) rhBMP-2; (3) PuraMatrix (PM), a synthetic self-assembling peptide (RADA16-I) consisting of a 16-amino acid sequence and with a three-dimensional structure; and (4) PM/rhBMP-2. Each cylinder was covered with a titanium lid. After 8 weeks, the animals were sacrificed, and ground sections were obtained for histomorphometric analysis.
Results: Histomorphometric analysis showed that regenerated tissue in the cylinder with PM/rhBMP-2 was significantly increased compared to the empty control. The mean area values of regenerated tissue in the cylinders were 35.80% ± 10.35% (control), 47.94% ± 5.65% (rhBMP-2), 48.94% ± 11.33% (PM), and 58.06% ± 14.84% (PM/rhBMP-2). The mean area values of newly formed bone in the cylinders were 9.39% ± 4.34% (control), 14.03% ± 2.25% (rhBMP-2), 13.99% ± 2.15% (PM), and 16.61% ± 3.79% (PM/rhBMP-2). Neither rhBMP-2 nor PM alone significantly enhanced bone regeneration compared to the empty control cylinder.
Conclusions: PM with rhBMP-2 significantly enhanced bone regeneration on the bone augmentation model in a rabbit. PM promises to be a useful alternative synthetic material as a carrier for rhBMP-2 for bone regeneration.

Keywords: bone morphogenetic protein-2, bone regeneration, calvarial model, self-assembling peptide

Purpose: The purpose of this article was to compare the yields of stromal multipotent stem cells (CD34+ and CD105+) and hematopoetic multipotent stem cells (CD44+) obtained from different areas via bone marrow aspiration (BMA).
Materials and Methods: Sixty 60-mL bone marrow aspirates were taken from the tibial plateau, the anterior ilium, and the posterior ilium using a single point-of-care BMA technique and a single BMA concentration (BMAC) device. A 1-mL portion of each sample was used to determine CD stem cell concentrations and the nucleated cell count. The remaining BMA was centrifuged to separate the more mature red blood cell precursors from the stem cells and then concentrate the latter into a BMAC. The BMAC yield of 10 mL was analyzed with flow cytometry and nucleated cell counts to derive a concentration factor for the BMAC.
Results: The yield of total nucleated cells was equal between the anterior and posterior ilium and more than twice that obtained from the tibial plateau. The CD44+ and CD105+ cell yields were also nearly equal between the anterior and posterior ilium but more than twice that of the tibial plateau; however, the ratios between the three different stem cell types in BMAC obtained from the different areas suggest varying potentials for tissue development.
Conclusions: The ilium is the preferred donor site for obtaining autologous stem cells at the point of care. The tibial plateau yielded only half as much bone marrow multipotent/progenitor stem cells as did the anterior and posterior ilium. The composition of the BMAC from each site suggests that the potential for differentiation into various cell types changes depending on the source of bone marrow, but that BMAC represents 6.5 ± 1.0 concentration factor from BMA.

Keywords: bone marrow aspiration, stem cell harvest

Purpose: The primary objective of this study was to evaluate the safety of a tissue-engineered human ex vivo-produced oral mucosa equivalent (EVPOME) in intraoral grafting procedures. The secondary objective was to assess the efficacy of the grafted EVPOME in producing a keratinized mucosal surface epithelium.
Materials and Methods: Five patients who met the inclusion criteria of having one mucogingival defect or a lack of keratinized gingiva on a nonmolar tooth, along with radiographic evidence of sufficient interdental bone height, were recruited as subjects to increase the width of keratinized gingiva at the defect site. A punch biopsy specimen of the hard palate was taken to acquire oral keratinocytes, which were expanded, seeded, and cultured on an acellular dermal matrix for fabrication of an EVPOME. EVPOME grafts were applied directly over an intact periosteal bed and secured in place. At baseline (biopsy specimen retrieval) and at 7, 14, 30, 90, and 180 days postsurgery, Plaque Index and Gingival Index were recorded for each subject. In addition, probing depths, keratinized gingival width, and keratinized gingival thickness were recorded at baseline, 30, 90, and 180 days.
Results: No complications or adverse reactions to EVPOME were observed in any subjects during the study. The mean gain in keratinized gingival width was 3 mm (range, 3 to 4 mm). The mean gain in keratinized gingival thickness was 1 mm (range, 1 to 2 mm). No significant changes in probing depths were observed.
Conclusion: Based on these findings, it can be concluded that EVPOME is safe for intraoral use and has the ability to augment keratinized tissue around teeth. Future clinical trials are needed to further explore this potential.

Keywords: clinical trial, Good Manufacturing Practices, keratinized gingiva, keratinocytes, oral mucosa, tissue engineering

The modified osteo-odonto keratoprosthesis (MOOKP) is a biologic keratoprosthesis that is used to treat a severely scarred cornea. The procedure involves multiple stages, including the transplantation of buccal mucosa to the damaged ocular surface and the implantation of an osteo-odonto lamina with a mounted polymethylmethacrylate lens. Among the keratoprostheses currently available, the MOOKP has proven to be the most effective based on the number of patients who have undergone the procedure and the duration of documented follow-up. Upon successful biointegration of the osteo-odonto lamina, the keratoprosthesis is able to resist resorption, provide stability, and prevent bacterial invasion and epithelial ingrowth. The effectiveness of the MOOKP is dependent on the anatomic and physiologic characteristics of the dental tissues and periodontal ligament.

Keywords: biointegration, keratoprosthesis, lamina, vision

Purpose: Following initial positive reports of the use of bone marrow aspirate concentrate (BMAC) in combination with bovine bone mineral (BBM) in augmentation procedures, the technique was evaluated in patients with mandibular deficiency.
Materials and Methods: Two adult patients required surgical correction of a deficient alveolar ridge (one patient showed horizontal deficiency only, and the other patient presented with horizontal and vertical deficiency) prior to dental implant placement. In both patients, the reconstruction was performed with BBM in combination with mononuclear cells concentrated by the BMAC method using different techniques.
Results: The patients recovered well from all surgical procedures. Histologically, there was uniform bone formation, which allowed placement of dental implants.
Conclusion: The results suggest that the use of BMAC in combination with BBM, without autogenous bone, has the potential to restore horizontal and vertical mandibular alveolar defects, providing a functional bone structure and allowing dental implant placement for subsequent prosthetic rehabilitation.

Keywords: bone marrow, bovine bone matrix, cell transplantation, horizontal augmentation, mandible, mesenchymal stem cells

This paper is a retrospective report of the treatment of six patients with severely resorbed maxillae. Patients were treated, based on the amount of maxillary retrognathia, with either a Le Fort I downfracture or a "horseshoe" interpositional sandwich osteotomy, along with sinus elevation. Recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier was used for grafting in all patients, either alone or in combination with other grafting materials. Implants were placed and the patients were restored with fixed prostheses. Both grafting techniques are described, and the treated patients are presented.

Keywords: bone morphogenetic protein-2, dental implants, interpositional grafting, Le Fort I downfracture, retrofitting prosthesis, sandwich osteotomy

Purpose: To evaluate the use of a nonperforated titanium occlusive device over a bone morphogenetic protein-2 in an absorbable collagen sponge (BMP-2/ACS) in grafting the bone around high-profile (ie, supracrestal) dental implants in rabbit tibiae.
Materials and Methods: Eight New Zealand white rabbits were used for the experiment. Two implants were placed in the right tibia of each rabbit, with 4 mm of each implant placed supracrestally ("high-profile" placement) in four groups of two rabbits each: control, titanium shell only, titanium shell over buffered collagen, and titanium shell over BMP-2/ACS. The animals were sacrificed after 3 or 6 weeks. Calcified and nondecalcified histologic preparation was carried out to evaluate bone formation and degree of osseointegration.
Results: Three of the eight animals developed tibial fractures. The two BMP-2 test animal tibiae remained intact, with the 3-week specimen showing very little bone formation inside or outside of the titanium chamber and the 6-week specimen showing bone mostly outside of the chamber.
Conclusion: The placement of BMP-2 beneath an occlusive nonperforated titanium shell next to a high-profile implant did not result in significant bone formation.

Keywords: bone augmentation, bone morphogenetic protein-2, high-profile dental implants, titanium shell

Purpose: The use of a magnesium-based bone cement, OsteoCrete, has shown promise as a means to secure bone and tendon-to-bone connections in orthopedic medicine. The presence of a bone cement to fill the residual socket and stabilize a dental implant during healing could make immediate implant placement in molar sites more predictable. The aim of this study was to determine whether this magnesium-based bone cement can be used predictably for this purpose.
Materials and Methods: The mandibular third premolars and first molars were extracted bilaterally from four mongrel dogs (60 to 80 lb each). Implants were placed in each extraction socket and supported by only 2 to 3 mm of apical furcation bone. OsteoCrete bone cement was placed randomly for implant stabilization in half of the sites. Clinical healing was evaluated until the 4-month time point. All animals were then sacrificed, and mandibular en bloc resection was performed for histologic evaluation of the biologic response and bone-to-implant contact.
Results: Clinically, healing showed a poor response when the test site implant was left exposed in a one-stage manner. No statistically significant difference was noted in bone-to-implant contact (52% in test sites versus 44% in control sites). Histologic specimens showed no adverse biologic response to the material but only minimal replacement at 4 months.
Conclusions: OsteoCrete bone cement was successful in stabilizing the immediate dental implant in a large extraction socket when placed in a closed environment in the dog model but did not show a benefit as compared to controls. The limited data warrant further studies to determine the further potential of this material.

Keywords: alloplast, animal study, bone cement, immediate dental implant, immunohistology, synthetic bone graft

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no abstract available