Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bone Substitutes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMed2006

[Experimental studies on the porous calcium phosphate cement combined with recombinant human bone morphogenetic protein 2 for bone defects repair].

OBJECTIVE: To study in vitro sustained release behaviour of the recombinant human bone morphogenetic protein 2 (rhBMP-2) from the sample which porous calcium phosphate cement (PCPC) was combined with rhBMP-2, and to evaluate the effect of PCPC/rhBMP-2 composite on repairing bone defect in the animal study. METHODS: rhBMP-2 was absorbed into PCPC by vacuum-adsorption and freeze-dried at -40 degrees C, the PCPC/rhBMP-2 enwrapped with chitosan as the experimental group, the pure PCPC/rhBMP-2 as the control group, then the sustained release of rhBMP-2 from PCPC was determined in simulated body fluid (SBF) by UV-VIS spectrophotometer. At same time, the PCPC/rhBMP-2 composites with chitosan were implanted into the (4.2 mm x 5.0 mm femora defects of rabbits, which were considered as the experimental group, whereas in the control group only PCPC was implanted. The effect of repairing bone defect was evaluated in the 4th and 8th week postoperatively by radiograph and histomorphology. RESULTS: The PCPC have a high absorption efficiency to rhBMP-2, and the release of rhBMP-2 was sustained release system. The release of rhBMP-2 from PCPC in the experimental group (99% after 350 hours) was slower than that in the control group (100% after 150 hours). In the experimental group, the radiological and histomorphological evaluations showed that the interfaces between the materials and host bones became blurred both at 4th and 8th week. The implanted materials were partially absorbed, and the implanted areas exhibited the formation of new bone. In the control group, a little amount of new bones was observed. CONCLUSION: The PCPC shows great clinical potential as a carrier for rhBMP-2. The PCPC/rhBMP-2 composite possesses much potentialities of osteoinductivity and the ability of repairing bone defect, so it can be used as a novel bone substitute clinically.

Animals↗
PubMed2005

In vivo biological performance of composites combining micro-macroporous biphasic calcium phosphate granules and fibrin sealant.

INTRODUCTION: Fibrin glues are currently used by surgeons and can facilitate the handling of biomaterials. Combining fibrin glue with calcium phosphate bioceramics gives a mouldable composite that cements the granules into the implantation site. In addition to the mechanical aspect of the composite, it has been suggested that the mixture also promotes wound healing. These human blood derivatives contain natural (aprotinin) or synthetic (tranexamic acid) antifibrinolytic substances. We compared the bioactivity of two composites combining calcium phosphate granules with two different types of fibrin glue, one with aprotinin and the other with tranexamic acid. MATERIALS AND METHODS: The composite was composed of fibrin glue (Tissucol) and 1 to 2 mm granules of biphasic calcium phosphate granules (MBCP) with a volume ratio of 1 for 2. Bone cavities were drilled in 12 New Zealand rabbits and filled with a composite with aprotinin-fibrin glue on the right condyle and one with tranexamic acid-fibrin glue on the left condyle. The rabbits were randomized into two groups: 3 and 6 weeks of delay. Light microscopy, scanning electron microscopy and image analysis were performed. RESULTS: No adverse reactions were observed in either sample. Bony ingrowth associated with bioceramic resorption by osteoclastic TRAP-positive cells was noted. No significant difference was observed between the two composites. The bony ingrowth and ceramic resorption were qualitatively and quantitatively similar with both composites. CONCLUSION: This study demonstrated that the choice of a natural (aprotinin) or synthetic (tranexamic acid) antifibrinolytic agent in the fibrin sealant associated with calcium phosphate granules and used as a bone substitute had no effect on the bioactivity of the composite. It remained efficient in bone reconstruction, no adverse effects were observed, and the bony ingrowth was qualitatively and quantitatively equivalent with the two types of fibrin sealant.

Animals↗
PubMed2003

Sinus floor augmentation with beta-tricalciumphosphate (beta-TCP): does platelet-rich plasma promote its osseous integration and degradation?

When dental implants are to be inserted, sinus floor augmentation is an effective treatment procedure to improve bone height in the posterior maxilla. In addition to autogenous bone material, allogenic materials, e.g. beta-tricalciumphosphate (beta-TCP), have been used successfully. The purpose of this study was to investigate whether the combination of beta-TCP with platelet-rich plasma (PRP) enhances bony regeneration and resorption of the tricalciumphosphate material. In a randomized prospective trial, 45 sinus floor elevations were performed in 39 patients. In 22 sites, PRP was added to the beta-TCP granules, while in 23 sites beta-TCP without PRP was used. Six months later, bone specimens were harvested from the augmented region during the implant insertion procedure. The formation of new bone was about 8-10% higher when PRP was applied. A faster degradation of the ceramic bone substitute was not observed. In conclusion, when PRP was added to beta-TCP, bone regeneration was supported to a small extent. However, the resorption of beta-TCP was not accelerated and foreign-body giant cells and soft tissue surrounding the beta-TCP granules were present.

Absorbable Implants↗
PubMed2006

Characterization and bioactivity of tape-cast and sintered TCP sheets.

The purpose of this study was to investigate the influence of sintering temperature on in vivo and in vitro bioactivities of sintered tricalcium phosphate (TCP) sheets prepared by the tape casting technique. Green sheets of beta-TCP prepared by tape casting were sintered for 2 h in a furnace at atmospheric pressure, at five different sintering temperatures: 900, 1000, 1100, 1150, and 1200 degrees C. Measurement of X-ray diffraction and Fourier transform infrared spectrometry showed the presence of alpha-tricalcium phosphate phase in the TCP sheet sintered at 1200 degrees C, in addition to beta-TCP phase. As compared with the other sintered TCP sheet, the TCP sheet sintered at 1200 degrees C demonstrated a lower dissolution rate in phosphate buffered saline solution at 37 degrees C and pH 7.4 over 24 weeks, and more amount of apatite formation in Hanks' balanced salt solution with pH 7.4 was observed. After 4 weeks' implantation of sintered TCP sheets into tibial diaphyses of rabbits, the bone-sheet contact of the TCP sheet sintered at 1200 degrees C was significantly higher than that of the TCP sheet sintered at 900 degrees C. These results indicate that a flat sintered TCP sheet prepared by tape casting is a promising material for a bone substitute.

Animals↗
PubMed2006

Quantitative morphometric evaluation of critical size experimental bone defects by microcomputed tomography.

Our aim was to show that microcomputed tomography is a useful tool for acquiring high-resolution three-dimensional tomographic images to assess bone healing, the interface with materials, and the biocompatibility of bone substitutes. Acquired images can be used for non-invasive quantitative morphometric analysis of regenerating bone, leaving the option for conventional histology to be an adjunct used at defined intervals. The temporal characterisation of the mineralisation of bone potentially has a critical role in the understanding of the dynamics of mineralisation of healing bone. This has applications both for degradable and bioactive materials and for pharmaceutical products that act on bone. Formal validation of this promising new technique will be a critical part of continuing studies.

Animals↗
PubMed2000

Use of hydroxyapatite cement to support implants in extraction sockets.

Bioactive cements based on calcium phosphate chemistry have been developed to serve as bone substitute materials. One such commercial product, BoneSource, is a hydroxyapatite cement (HAC) used for small bone defects in the craniofacial complex. We have investigated the possibility that HAC could be used to support bone growth adjacent to dental implants placed in immediate tooth extraction sites. Variable levels of bone contact were noted up to 3 months postimplantation. Considerable loss of HAC occurred and was thought to be because of "washout" of the cement before complete cement setting. When HAC was immobile in the surgical site, the bioactive nature of the cement led to HAC resorption and bone deposition. Efforts to maintain the HAC in situ should be expanded so that the full clinical potential of the HAC can be realized.

Absorbable Implants↗
PubMed2001

Synthesis of calcium-phosphate and chitosan bioceramics for bone regeneration.

Bioceramic composites were obtained from chitosan and hydroxyapatite pastes synthesized at physiological temperature according to two different syntheses approaches. Usual analytical techniques (X-ray diffraction analysis, Fourier transformed infrared spectroscopy, Thermo gravimetric analysis, Scanning electron microscopy, X-ray dispersive energy analysis and Porosimetry) were employed to characterize the resulting material. The aim of this investigation was to study the bioceramic properties of the pastes with non-decaying behavior from chitosan-hydroxyapatite composites. Chitosan, which also forms a water-insoluble gel in the presence of calcium ions, and has been reported to have pharmacologically beneficial effects on osteoconductivity, was added to the solid phase of the hydroxyapatite powder. The properties exhibited by the chitosan-hydroxyapatite composites were characteristic of bioceramics applied as bone substitutes. Hydroxyapatite contents ranging from 85 to 98% (w/w) resulted in suitable bioceramic composites for bone regeneration, since they showed a non-decaying behavior, good mechanical properties and suitable pore sizes.

Biocompatible Materials↗
PubMed2000

[Filling of bone defects with tricalcium phosphate beta in traumatology].

AIM OF STUDY: Synthetic bone substitutes like calcium phosphate ceramics have been used in orthopaedic surgery for several years. The aim of this study was to assess the results of the use of tricalcium phosphate beta for filling bone defects in trauma cases. PATIENTS AND METHOD: beta tricalcium phosphate was used in 24 trauma cases. The GESTO classification (Association pour l'étude des Greffes et Substituts Tissulaires en Orthopédie) and a qualitative scale were used to estimate the integration. RESULTS: With a mean follow-up of 20 months, integration was excellent in 41.2%, good in 29.2% and moderate in 17.4%. No fibrous encapsulation was observed around the implants in any case. Sepsis occurred in 3 cases with open fractures. CONCLUSION: beta-Tricalcium phosphate seems in our experience to be an excellent bone substitute for filling bone defects in trauma cases.

Adult↗
PubMed2002

Bioactivity and osseointegration study of calcium phosphate ceramic of different chemical composition.

Synthetic hydroxyapatite (HA) and tricalcium phosphate (TCP) are promising bone-substitute materials in the orthopaedic and dental fields, as their chemical composition is similar to that of bone. This study investigated the osseointegration performance of carbonated biphasic calcium phosphate (CBCP) ceramics containing carbonated hydroxyapatite and tricalcium phosphate prepared by microwave irradiation, in femoral defects of dogs. The defects were created as 3-mm holes on the lateral aspect of femur and filled with the implant material. The serum was collected postoperatively and biochemical assays for alkaline phosphatase activity levels were carried out. The animals' defective sites were radiographed at 4, 8, and 12 weeks. The radiographic results showed that the process of ossification started after 4 weeks and the defect was completely filled with new bone after 8 weeks. Histological examination of the tissue showed the osteoblastic activity inducing the osteogenesis in the defect. The complete haversian system with osteoblastic and osteoclastic activity and bone remodelling process were observed after 12 weeks. The alkaline phosphatase activity levels also correlated with the formation of osteoblast cells. This calcium phosphate ceramic has proved to work well as a biocompatible implant and as an osteoconductive and osteoinductive material for the filling of bone defects.

Animals↗
PubMed2005

Wear particles and surface topographies are modulators of osteoclastogenesis in vitro.

Prosthetic and osteosynthetic implants from metal alloys will be indispensable in orthopedic surgery, as long as tissue engineering and biodegradable bone substitutes do not lead to products that will be applied in clinical routine for the repair of bone, cartilage, and joint defects. Therefore, the elucidation of the interactions between the periprosthetic tissues and the implant remains of clinical relevance and several factors are known to affect the longevity of implants. Within this study, the effects of metal particles and surface topography on the recruitment of osteoclasts was investigated in vitro in a coculture of osteoblasts and bone marrow cells. The cells were grown in the presence of particles of different sizes and chemical composition or on metal discs with polished or sandblasted surfaces, respectively. At the end of the culture, newly formed osteoclasts were counted. Osteoclastogenesis was reduced when particles were added directly to the coculture. The effect depended on the size of the particles, small particles exerting stronger effects than larger ones. The chemical composition of the particles, however, did not affect the development of osteoclasts. In cocultures grown on sandblasted surfaces, osteoclasts developed at higher rates than they did in cultures on polished surfaces. The data demonstrate that wear particles and implant surfaces affect osteoclastogenesis and thus may be involved in the induction of local bone resorption and the formation of osteolytic lesions, leading eventually to the loosening of orthopedic implants.

Animals↗
PubMed2005

[An experimental study on repairing bone defect with composite of beta-tricalcium phosphate-hyaluronic acid-type I collagen-marrow stromal cells].

OBJECTIVE: To observe the ability to repair bilateral radius bone defect with the composite of beta-tricalcium phosphate (PTCP), hyaluronic acid (HA), type I collagen (COL-I) and induced marrow stromal cells (MSCs), and to investigate the feasibility of the composite as a bone substitute material. METHODS: The MSCs of the New Zealand white rabbits were induced into osteoblasts, then combined with beta-TCP, HA and COL-I. Thirty New Zealand white rabbits were made the bilateral radius bone defects of 2 cm and divided into groups A, B and C. After 8 weeks, beta-TCP-HA-COL-I-MSCs (group A, n=27 sides), autograft (group B, n=27 sides)and no implant (group C as control, n=6 sides) were implanted into the areas of bilateral radius bone defects, respectively. The structure of the composite was observed by scanning electron microscope. The repairing effect was observed by gross, histomorphology, X-ray examination, and the degradation rate of inorganic substance at 4, 8 and 12 weeks. The osteogenic area and biomechanics of group A were compared with those of group B at 12 weeks. RESULTS: The MSCs could stably grow in vitro, relatively rapidly proliferated, and could be induced into the osteoblasts. The composite was porous. The results of gross, histomorphology and X-ray showed that the bone defects were perfectly repaired in group A and group B, but not in group C. The osteogenic area or biomechanics had no statistically significant difference between groups A and B (P> 0.05). The weight of inorganic substance in group A were 75%, 57% and 42% at 4, 8, 12 weeks, respectively. CONCLUSION: MSCs can be used as seed cells in the bone tissue engineering. The composite has porous structure, no reactions of toxicity to the tissue and rapid degradation, and it is an ideal carrier of seed cells. The beta-TCP-HA-COL-I-MSCs composite has the high ability of repairing bone defect and can serve as an autograft substitute material.

Animals↗
PubMed1999

Biphasic calcium phosphate/hydrosoluble polymer composites: a new concept for bone and dental substitution biomaterials.

Calcium phosphate materials have been increasingly employed in orthopedic and dental applications in recent years and are now being developed for use in noninvasive surgery or as carriers for drug delivery systems. We developed an injectable bone substitute (IBS) constituted of biphasic calcium phosphate and a hydrosoluble polymer as a carrier. In vivo biocompatibility and biofunctionality of IBS were tested in rabbits using implants in osseous and nonosseous areas. The results obtained demonstrated that the concept of IBS, a filler without initial mechanical properties but able to be rapidly resorbed and replaced by newly formed bone, can be applied to new surgical applications in orthopedic surgery, maxillofacial surgery, and dentistry for pulp capping and root filling.

Animals↗
PubMed2003

The effect of silica-containing calcium-phosphate particles on human osteoblasts in vitro.

There is an ongoing need for more effective and less costly bone substitutes. It has previously been proposed that silica-containing bioactive glass would be more effective as a bone repair material because of its physiochemical properties. Three newly synthesized silica-containing bioactive glass formulations, HA-31 (25%), HA-11 (50%), and HA-13 (75%), were tested as biocompatible substrates for the continued proliferation and phenotype expression of human bone cells in vitro. Two currently available bioactive glasses (BioGlass(R), Hydroxyapatite) served as comparisons. The biocompatibility of these bioglasses, as well as their osteoconductive properties, was assessed by employing primary cultures of human osteoblasts and human synoviocytes for 4 days. The results obtained demonstrated that the three new bioglasses enhanced the proliferative response of osteoblasts compared with osteoblasts cultured alone. Reverse Transcription Polymerase Chain Reaction (RT-PCR) analysis indicated that osteoblasts retained their phenotypic expression by continued expression of collagen type I and alkaline phosphatase. The newly synthesized preparations of silica-containing bioactive glass did not induce stimulation of proinflammatory markers iNOS and IL-1beta in synoviocytes. In conclusion, the newly synthesized silica-containing bioactive glasses are biocompatible substrate for bone-forming osteoblasts. However, the formulations tested did not show significant advantage over the currently available bioactive glasses in vitro.

Alkaline Phosphatase↗
PubMed1999

Grafting of large defects of the jaws with a particulate dentin-plaster of paris combination.

OBJECTIVE: The purpose of this report is to show the usefulness and discuss the effects of a particulate dentin and plaster of paris combination as a bone graft material in jaw defects. STUDY DESIGN: This was a retrospective evaluation of 10 patients with jaw defects who underwent grafting with a combination of particulate dentin and plaster of paris. The material was used when the defects were more than 20 mm in diameter. The ratio was 2:1 by weight. Patients were examined for any evidence of infection and recurrence during the follow-up periods. RESULTS: During a mean follow-up of 52.2 months (range, 50 to 57 months), patients had minor immediate postoperative complications. These complications were swelling and perforation; they were treated without problems through use of incision and drainage, antibiotic treatment, and buccal flap. CONCLUSIONS: On the basis of the results that we obtained radiographically and clinically, it may be concluded that the particulate dentin plaster mixture is a useful and readily available material for bone substitute.

Adolescent↗
PubMed2003

In vivo bone engineering in a rabbit femur.

The repair of bone defects in reconstructive surgery has significant limitations. Donor site morbidity, limited supply of autograft, and risks and complications associated with allografting and synthetic bone substitutes are among the most significant. In an effort to address these problems, the search for an ideal bone replacement has led to the development of a new method of poly(lactide-co-glycolide) (PLGA) foam processing, enabling the production of a biodegradable scaffold with similar porosity to human trabecular bone. In this study, these scaffolds were evaluated for bone repair in vivo in a femoral critical-sized segmental defect in New Zealand White (NZW) rabbits. Three groups of nine animals were investigated. In the first group, the critical-sized defects were empty. Scaffolds alone were implanted in the second group, whereas autologous bone marrow cell-loaded scaffolds were implanted in the third group. Animals ambulated freely for 8 weeks after surgery, and bone formation throughout the defects was serially assessed radiographically and quantified using a bone formation index (BFI) measure. Postmortem radiography and histology were also undertaken to examine bone formation. There was a significant effect of applying this technology to the amount of bone formed in the defects as determined by the BFI (F = 3.41, P < 0.05). The mean BFI for the cell-loaded scaffolds was greater than for the control group at all measured time points (2-, 4-, 6-, and 8-week radiographs). This difference was significant for the 2- and 8-week radiographs (P < 0.05). Qualitative histological assessment confirmed these findings. We concluded from these findings that these PLGA scaffolds loaded with marrow-derived progenitor cells yield significant bone formation in a critical-sized rabbit femoral defect. This technology comprising a novel scaffold design and autologous cells may provide an alternative to current strategies for reconstruction of bony defects.

Absorbable Implants↗
PubMed2003

Hydroxyapatite cement (BoneSource) for repair of critical sized calvarian defects--an experimental study.

AIM: In an experimental study the hydroxyapatite cement BoneSource was tested for the ability in relation to the defect size and for its resorption properties. MATERIAL AND METHODS: In an animal study, BoneSource was applied to repair bicortical defects of different sizes in frontal bones of six Goettingen minipigs. The area was evaluated radiographically and histologically 12, 18 and 40 weeks postoperatively. RESULTS: After 40 weeks approximately 90% of the hydroxyapatite cement had been resorbed and replaced with bone. After 12 weeks, approximately 30% had been degraded, and 40% after 18 weeks. In small bone defects, the mucosa of the frontal sinus lined the bone substitute (BoneSource). In the reconstruction of large areas, a membrane was used to stabilize the material. Despite this membranous support, BoneSource material prolapsed into the frontal sinus. DISCUSSION: Hydroxyapatite cement is for the repair of bone defects. It can be moulded to shape the reconstruction. Its use is limited by the defect size and the need for a dry bed. CONCLUSION: BoneSource is well suited to repair small defects with proven high biocompatibility. However, in large defects, the material is not sufficiently stable.

Animals↗
PubMed1995

Light and transmission electron microscopic studies following frontal sinus obliteration with ionomer cement in cats.

Osteoplastic frontal sinus surgery in combination with sinus obliteration can be performed for various indications, including chronic sinusitis, frontal sinus trauma and removal of osteomas. In an experimental study using cats, the mucous lining of the frontal sinus was removed, the nasofrontal duct sealed with semifluid ionomer cement and the cavity filled with Ionogran, a solid and porous bone substitute based on ionomer cement. Histological investigations up to 1 year after surgery showed increasing sinus obliteration by regenerating bone, starting from the sinus wall, and formation of connective tissue between the cement grains. There was no evidence for mucosal regeneration. Electron microscopic examination of the interface between the cement and connective tissue revealed mesenchymal cells, collagen fibers and areas of mineralization in close contact with the implant material. Newly formed connective tissue matrix in intimate contact with the cement was a good indication for biocompatibility of the material and is a possible explanation for the implant's solid adhesion to bone. The present findings indicate that Ionogran is a suitable alloplastic material for experimental frontal sinus obliteration in cats.

Adhesiveness↗
PubMed2002

Orthodontic movement into bone defects augmented with bovine bone mineral and fibrin sealer: a reentry case report.

Periodontal disease can lead to migration of anterior teeth with the presence of infrabony defects. This creates the opportunity for treating such patients with a combined orthodontic-periodontic treatment. In the presented clinical case, an adult periodontal patient with extrusion of the maxillary central incisors and an infrabony defect on their lingual aspects was treated. During the surgical procedure, the bone defects were augmented with a combination of porous bovine bone mineral (Bio-Oss) and a fibrin-fibronectin sealing system (Tissucol). Ten days after surgery, the active orthodontic treatment started, and the teeth were intruded and realigned, moving the roots into the defects. After 6 months, the orthodontic appliances were removed and the teeth were retained by means of a resin-bonded splint. At this time, reduction in probing pocket depth and gingival recession was detected. Twelve months after the initial surgery, a reentry procedure was performed, showing complete filling of the predisposing defects with the presence of bone-like hard tissue. These clinical results suggest that teeth can be successfully moved and intruded into bone defects previously augmented with bovine bone substitute and fibrin glue. During the orthodontic treatment, this combined augmentation material was able to be replaced by bone-like hard tissue. At the end of the therapy, an improvement in esthetics and periodontal health status was registered.

Alveolar Bone Loss↗