PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Bone Substitutes”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 361 records · Page 20Linked to original sources

[Regeneration capacity of the iliac crest after spongiosa removal in humans--induction by phosphate ceramics?].

The starting point for the investigation of calcium phosphate ceramics is given by the bone regeneration, including osteo-conduction, osteo-stimulation and osteo-induction. The amount of the autogenous bone, which can be used for transplantation to induce the organo typical regeneration, is a small one. Based on animal experiments we created a standardized model for investigation of bone regeneration, using the human iliac crest. The empty iliac crest was filled by hydroxylapatite, tricalcium phosphate, Kiel bone or it remained empty as a control group. Clinical examination, X-ray control, blood chemistry and documentation were done with 104 patients divided in these four groups. Radiography, histological examination and morphometry were done with biopsies of 40 patients. The results show a bony ingrown into the ceramic material. The pores were filled by lamellar bone with new grown osteons. The ceramic granules are complete integrated. The ceramic blocks are only fixed at the edges and at the surface by bone trabeculae. The Kiel bone is surrounded by fibrous tissues without any contact to new built bone. It doesn't act as a bone substitute. The bone regeneration in the not fulfilled iliac crest was fast and of a hard quality of lamellar bone and of big amount. Both ceramics show remarkable degradation. The tricalcium phosphate brakes into pieces and shows dissolution. The hydroxylapatite in smaller particles. The degradation stopped, if the particles were surrounded by new bone. These ceramics can be used as augmentation material in combination with autogenous bone. They act as bone substitutes. The integration and bonding to new bone is complete and can be loaded by mechanical strength.

Adult↗

Histomorphometric analysis of natural bone mineral for maxillary sinus augmentation.

PURPOSE: Lack of bone height in the posterior maxilla often necessitates augmentation prior to or simultaneously with dental implant placement. The purpose of this clinical study was to evaluate the use of the natural bone mineral Bio-Oss alone or in combination with autogenous bone in sinus floor elevations performed as 1- or 2-step procedures. MATERIALS AND METHODS: Thirty-eight patients required sinus augmentation. Natural bone mineral alone was used in sinus floor augmentation in 21 patients. In 13 patients, a mixture of the bone substitute and autogenous bone was used, and in 4 patients autogenous bone alone was used. In all of the patients, samples were taken for biopsy 3 to 8 months postoperatively, and bone regeneration was evaluated histologically and histomorphometrically. RESULTS: In all patients, the amount of new bone significantly increased over the observation time, while marrow areas decreased. There was no statistically significant difference in the amount of new bone formation between the Bio-Oss group (new bone 29.52% +/- 7.43%) and the Bio-Oss/autogenous bone group (new bone 32.23% +/- 6.86%). In the 4 patients treated with autogenous bone alone, a greater amount of newly formed bone was found; however, in these cases the area volume filled was smaller than in the other 2 groups. DISCUSSION: The data showed that new bone formation takes place up to 8 months after sinus floor elevation and that there is no difference in the amount of bone formation between procedures done with the bone substitute alone or with the mixture of the substitute and autogenous bone. CONCLUSION: These data suggest that predictable bone formation can be achieved with the use of Bio-Oss.

Adult↗

The use of an injectable bone graft substitute in tibial metaphyseal fractures.

Eight consecutive patients with severely comminuted proximal or distal tibial metaphyseal fractures were surgically treated with a novel injectable, in situ hardening calcium sulfate material to provide temporary intraoperative structural support until instrumentation was appropriately placed. The calcium sulfate bone substitute was also used as a bone void filler to provide an osteoconductive environment following stabilization. Bone regrowth was observed in all patients and, in seven of the eight patients, 90%-100% bone formation was observed within 3 months. The bone substitute had almost completely resorbed by 3 months in all patients. One patient with extensive initial bone loss required a second bone graft. Although the patient sample size was small, the success rate of treating severely comminuted fractures was significantly better than in reports using only internal fixation. Injectable bone substitute for minimally invasive surgery to repair metaphyseal fractures.

Adult↗

[Clinical lymphographic diagnosis of posttraumatic edema in the substitution of bone defects].

The method of direct "lower" lymphography of the medial superficial collector was used for the examination of 11 patients with a moderate chronic posttraumatic edema developed against the background of atrophy of muscle tissues before and in the process of substituting bone defects after Ilizarov. In substituting bone defects against the background of a previous posttraumatic blockade of lymph vessels and their alterations there appears a complete or partial decompensation of the lymph flow, resulting in the development of edema in the atrophied earlier segments of lower extremities. In part of the patients with substituted bone defects the edema increased with persistent previous alterations. In other ones there appeared new foci of the rearrangement of lymph vessels.

Bone and Bones↗

Bone graft substitutes.

The current gold standard of bone grafts is the autograft since it possesses all the characteristics necessary for new bone growth, namely osteoconductivity, osteogenicity and osteoinductivity. However, the autograft has its limitations, including donor-site morbidity and supply limitations, hindering this as an option for bone repair. An extensive list of currently available alternatives to bone grafts is provided, along with a classification scheme that divides these bone graft substitutes into five groups depending on the primary material composition: allograft, cell, factor, ceramic and polymer. Of the bone graft substitutes listed, several are discussed in detail. Beyond the current state of the art, attention is paid to what lies ahead in the field of bone graft substitutes. Biodegradable composite structures and various new architectures are discussed, as are newly developed polymeric materials, with tissue engineering providing the platform for future directions within this discipline.

Animals↗

Synthetic bone graft substitutes.

Some of the most significant advances in biomaterials over the last 20 years have been in the field of bone graft substitutes. Additionally, bone growth proteins were one of the first tissue-specific morphogenic factors to be characterized and produced by recombinant genetic technology. Consequently, the development of a new generation of totally synthetic, biologically active bone graft substitutes is just now beginning to move from the laboratory to clinical testing. It is entirely possible that within the next 10 to 15 years, the majority of "bone grafting" in craniofacial reconstructive surgery and in orthopedic surgery may be done with biologically active synthetic bone graft substitutes rather than natural bone sources. In fact, the harvesting of autogenous grafts may eventually prove to be the exception rather than the standard of care. Regardless of whether the potential of biologically active bone graft substitutes is ever fully realized, we now have a large number of synthetic alternatives to autogenous bone grafts for craniofacial skeletal augmentation and reconstruction. The reality of these synthetic bone graft substitutes is that no single material is "the best" for all applications. Instead, the specific biomaterial must be tailored to the individual site of application to achieve optimal results. The synthetic bone graft substitutes reviewed in this article represent only the "core" of synthetic biomaterials from which synthetic bone graft substitutes can be selected. Other articles in this monograph highlight the roles that various natural and biologically active bone graft substitutes play in craniofacial skeletal augmentation and reconstruction.

Bone Substitutes↗

[Natural coral calcium carbonate as alternative substitute in bone defects of the skull].

A biomaterial derived from natural corals with surgical applications is the calcium carbonate Biocoral. Since 1992 the author has been using this material as a bone graft substitute in maxillofacial surgery. Eighty-nine clinical implantations were done in 68 patients for different indications. The results suggested that coral grafts are well tolerated and are simultaneously partially ossified as the calcified skeleton is resorbed. Clinical cases show that use of this material has been successful.

Adult↗

A study of HAp/PLLA composite as a substitute for bone powder, using FT-IR spectroscopy.

Chemically synthesized hydroxyapatite/poly-L-lactide (HAp/PLLA) composite biomaterial was studied in vivo. The biocomposite was implanted into Balb/c Singen mice and after 1 and 3 weeks removed from their organisms and analyzed by the FT-IR spectroscopy. After 1 week of testing in vivo the implanted sample gave a spectrum in which absorption bands arising from newly formed functional groups of amine and peptide can be seen. After 3 weeks, a spectrum with pronounced absorption bands at 3420 and 1650cm(-1) assigned to newly generated collagen, a component of the extracellular connective-tissue matrix, was registered. Also, decrease of the intensity absorption band at 1760cm(-1) originating from the C=O group of PLLA indicates bioresorption of the PLLA used. Analysis of the microstructure of the sample surface by scanning electron microscopy before and after implantation revealed bioresorption of the PLLA polymer phase and generation of collagen fibers at the sites of implanted bioresorptive PLLA. A mixture of autologous bone powder and HAp/PLLA biocomposite was also examined. After implantation, the same final products as in the case of HAp/PLLA composite biomaterial used alone were found.

Animals↗

Augmentation of the narrow traumatized anterior alveolar ridge to facilitate dental implant placement.

Traumatic tooth loss leads to alveolar resorption especially in sagittal direction. This can be due to avulsion of bone substance during the accident itself or due to resorption of the alveolar crest that takes place afterwards. Shortage of bone can prevent proper positioning of dental implants unless the volume of bone is increased before implantation. In the maxillary anterior area, this is also an esthetic problem. Several treatment modalities have been presented to augment the bone. This report reviews the latest literature on bone grafting, bone substitutes, guided bone regeneration, osteocompression and distraction which are potentially useful in the anterior maxilla. A special emphasis is paid to the versatility of using a crestal split osteotomy, by means of chisels and osteotomes to widen the narrow ridge. Three examples are illustrated showing onlay grafting, preservation of alveolar width with alloplastic coral material and lateral widening of a narrow maxillary alveolar ridge, using the crestal splitting technique.

Adult↗

Bioactive glass as bone-graft substitute for posterior spinal fusion in rabbit.

Bioactive glass S53P4 and autogenous bone were studied as bone graft materials for spinal fusion in a rabbit model. Sixteen rabbits underwent surgery by a dorsal approach. A bioactive glass, a combination of bioactive glass and autogenous bone (70/30 vol%), and autogenous bone were implanted at two thoracolumbar vertebraes for 4 and 12 weeks. The volume, consolidation to vertebrae, and fusion of the graft material were evaluated with plain-film radiology, computed tomography (CT) and bone-mineral density measurements, and compared with histomorphometrical measurements. Radiological consolidation by CT of bone graft to underlying vertebrae at 12 weeks was observable in all groups. This was histologically confirmed as bone was growing from the vertebrae into the graft material. Radiologic fusion of vertebraes was, at 12 weeks, observable in all groups in 50--75% of the cases. The radiologic fusion seen at the CT scans could, however, not be confirmed by histology in any of the three groups. Significant differences for graft material and observation period with the use of bone-mineral density measurements (Hounsfield units) were also observable, with the highest measured values for the bioactive glass group and the lowest for the autogenous bone group. The results indicate that bioactive glass have potential as bone-graft material in spinal fusion. The reliability of radiologic evaluation methods in spinal surgery using bone substitutes is also questioned and discussed.

Animals↗

Bone repair techniques, bone graft, and bone graft substitutes.

This paper reviews the techniques and materials (bone graft and bone graft substitutes) that currently are used to treat nonunions and bone defects. The techniques reviewed are intramedullary nailing, plating, distraction osteogenesis, and electric stimulation. Bone graft and bone graft substitutes reviewed are as follows: vascularized bone transfers; autogenous bone graft; autogenous bone marrow; dimineralized bone matrix; growth factors; calcium sulphate; calcium phosphates; and allograft. The goal of management of fractures, nonunions, and segmental bony defects, is the return of function as quickly and completely as possible. Techniques and management strategies constantly are evolving to accomplish this goal. This paper reviews the history, indications, and limitations of bone repair techniques, methods of bone grafting, and materials available as bone graft substitutes.

Bone Plates↗

In vivo evaluation of calcium sulfate as a bone graft substitute for lumbar spinal fusion.

BACKGROUND CONTEXT: Posterolateral fusions of the lumbar spine have nonunion rates as high as 35%. The availability of autologous bone to promote fusion is limited, particularly for multilevel fusions. Bone substitutes have been proposed to augment or replace autologous bone for spinal surgery. Calcium sulfate offers high porosity, osteoconductivity, and high resorption rate. This material has been used successfully for treatment of long bone defects but has not been investigated as a bone graft substitute for spinal fusions. PURPOSE: To determine whether the use of calcium sulfate granules in conjunction with an implantable electrical stimulator is a safe and effective means of attaining spinal fusion. STUDY DESIGN/SETTING: A rabbit lumbar fusion model was used to assess a calcium sulfate bone graft substitute in combination with electrical stimulation for spinal fusion. METHODS: Thirty-six adult New Zealand White female rabbits were divided into three groups. Each group underwent a single-level (L5-L6) fusion, receiving 3.0 cc calcium sulfate granules with bone marrow aspirate from the iliac crest. Group 1 had no electrical stimulator applied. Groups 2 and 3 received a 40-microA (Group 2) or a 100-microA (Group 3) implantable electrical stimulator. The animals were sacrificed at 8 weeks, and the rabbit spines were subjected to radiographic assessment, manual palpation, and mechanical testing. RESULTS: Two rabbits died postoperatively. The radiographic assessment revealed no fusions occurred at the adjacent nonoperated control levels (L4-L5). There were no fusions observed within Group 1, containing the calcium sulfate and bone marrow aspirate alone. The sites with the implantable stimulators showed a dose-dependent increase in fusion stiffness. However, no fusion mass in Group 2 or 3 was graded as bilaterally complete. CONCLUSION: This study found that calcium sulfate as a bone graft substitute was unsuccessful in promoting spine fusion in a rabbit model. There was radiographic evidence of rapid resorption of the calcium sulfate within 4 weeks after surgery. The use of electrical stimulation created a dose-dependent increase in mechanical competence of the bony mass. However, the addition of direct current (DC) current did not significantly alter fusion rates with calcium sulfate used as the bone graft substitute in this model.

Animals↗

Management of segmental bony defects: the role of osteoconductive orthobiologics.

Our knowledge about, and the availability of, orthobiologic materials has increased exponentially in the last decade. Although previously confined to the experimental or animal-model realm, several orthobiologics have been shown to be useful in a variety of clinical situations. As surgical techniques in vascular anastomosis, soft-tissue coverage, limb salvage, and fracture stabilization have improved, the size and frequency of bony defects (commensurate with the severity of the initial injury) have increased, as well. Because all methods of managing segmental bony defects have drawbacks, a need remains for a readily available, void-filling, inexpensive bone substitute. Such a bone substitute fulfills a permissive role in allowing new bone to grow into a given defect. Such potential osteoconductive materials include ceramics, calcium sulfate or calcium phosphate compounds, hydroxyapatite, deproteinized bone, corals, and recently developed polymers. Some materials that have osteoinductive properties, such as demineralized bone matrix, also display prominent osteoconductive properties.

Animals↗

[Application of platelet-rich plasma in oral surgery. Theoretical background and practical requirements--review].

At the Department of Oral Surgery and Dentistry of Semmelweis University different studies have been carried out on the ossification, the use of various bone-substitutes and methods of bone augmentation. The aim of the present paper is to overview the literature background of an autogenous blood preparation (platelet rich plasma) with osteoinductive mechanisms applied in combination with osteoconductive bone substitutes. The role of platelet rich plasma is described in the mechanism of bone substitution, outlining the advantages of its application and the theoretical as well as the practical background of its clinical use. The routine use of platelet rich plasma has became very popular in a relatively short period of time in oral surgery though even today research and development are still very intensive in this field. According to many publications the use of autogenous blood preparations is an effective adjunctive method applied in bone substitutive therapies.

Blood Platelets↗

The biodegradation of hydroxyapatite bone graft substitutes in vivo.

Hydroxyapatite (HA) ceramics are widely used for bone reconstruction. They are osteoconductive and serve as structural scaffolds for the deposition of new bone. Generally, scaffold materials should be degradable as they affect the mechanical properties of the reconstructed bone negatively. Degradation by osteoclasts during the bone remodelling process is desirable but often does not take place. In the current study we analysed by light microscopy the degradation of two granular HA implants in critically sized defects in the mandibula of Goettingen mini-pigs five weeks after implantation. Bio-Oss consists of sintered bovine bone and NanoBone is a synthetic HA produced in a sol-gel process in the presence of SiO2. We found that both biomaterials were degraded by osteoclasts with ruffled borders and acid phosphatase activity. The osteoclasts created resorption lacunae and resorptive trails and contained mineral particles. Frequently, resorption surfaces were in direct contact with bone formative surfaces on one granule. Granules, especially of NanoBone, were also covered by osteoclasts if located in vascularised connective tissue distant from bone tissue. However, this usually occurred without the creation of resorption lacunae. The former defect margins consisted of newly formed bone often without remnants of bone substitutes. Our results show that the degradation of both biomaterials corresponds to the natural bone degradation processes and suggest the possibility of complete resorption during bone remodelling.

Acid Phosphatase↗

In vivo effect of fluoride-substituted apatite on rat bone.

Different types of calcium phosphate compounds are commercially available for medical and dental applications as bone substitute materials. Biological apatites contain several kinds of minor elements such as carbonate (CO3), magnesium (Mg), and fluoride (F) in enamel, dentin, and bone. It has been shown that F ion and F-substituted apatite promoted osteoblast proliferation and inhibited osteoclast cell activity. The purpose of this study was to investigate the in vivo rat tibia activity on F-substituted apatite (FAp). Apatites of unsintered calcium deficient apatite (CDA), and FAps, with low, medium, and high F concentrations, were implanted in rat tibia for 1 and 2 weeks. Implanted tissues were embedded in paraffin blocks, stained with hematoxylin-eosin and histomorphometrically observed. Results showed that low F concentration induced better and faster new bone formation in vivo compared to CDA. Therefore the results suggested that F as a minor element in bone rendered a suitable effect on bone formation in vivo.

Animals↗

Bone graft substitutes in the upper extremity.

The development of effective bone graft substitutes is one of the most important innovations in musculoskeletal surgery. Bone graft substitutes provide an osteoconductive scaffolding similar to those of autogenous bone. They eliminate donor site morbidity,decrease operative time and complexity and treatment costs, and improve patient satisfaction. Osteoinductive and osteogenic elements may be added to further stimulate and enhance healing and incorporation of the scaffolding substance into the adjacent bone. Bone graft substitutes have proven effective in the spine and larger long bones of the extremities. The continuing development of bone graft substitutes, evaluation of their efficacy relative to autogenous bone grafts and to each other, and their use in the hand and wrist are emerging fields.

Arm Bones↗