Closing capacity of cranial bone defects using porous calcium phosphate cement implants in a rabbit animal model (original) (raw)
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Histological evaluation of the bone response to calcium phosphate cement implanted in cortical bone
Biomaterials, 2003
The aim of this study was to investigate the physicochemical and biological properties of a newly developed calcium phosphate cement (CaP cement) implanted in cortical bone. CaP cement was injected as a paste into tibia cortical bone defects in goats. Polymethylmethacrylate (PMMA) bone cement was used as a control. The animals were killed after 3 days, 2, 8, 16 and 24 weeks. X-ray diffraction and Fourier transform infrared spectroscopy performed at retrieved samples showed that the CaP cement had set as a carbonate apatite and remained stable over time. Light microscopic evaluation showed that after 2 weeks the cement was in tight contact with the bone without any inflammatory reaction or fibrous encapsulation. At later time points, the CaP cement implants were totally covered by a thin layer of bone and osteoclasts, present at the interface, which were clearly resorbing the cement. At locations where CaP cement was resorbed, new bone was deposited. Transmission electron microscopy revealed that indeed a seamless contact existed between CaP cement and bone, as characterized by the occurrence of an electron dense line of 50-60 nm thick that covered the CaP cement. Osteoblasts, in contact with the cement, were depositing new bone. Although the bulk of the material was still in situ after 24 weeks, the progressive osteoclast resorption of the cement followed by new bone formation suggests that all of the material may be replaced eventually. In contrast to the CaP cement, the PMMA reference cement was always surrounded by a thin fibrous capsule. The results indicate that the investigated CaP cement is biocompatible, osteoconductive as well as osteotransductive and is a candidate material for use as a bone substitute. r
Journal of Cranio-Maxillofacial Surgery, 2005
Introduction: Aim of this experimental study was to assess the suitability of a new brushite calcium phosphate cement (chronOStInject) for cranioplasty and to compare the results with a commercially available apatite calcium phosphate bone cement (Biobon s ). Material and methods: A bilateral full-size craniotomy defect (23 mm in diameter) was created in the parietal bones of 18 adult Swiss Alpine sheep and filled with either chronOStInject or Biobon s . The observation intervals were 2, 4 and 6 months. Macroscopical, radiological, histological and histomorphometrical evaluations were performed. Results: New bone formation was moderate and did not differ significantly between the biomaterials. Cement resorption occurred centripetally in the chronOStInject group and proceeded significantly faster than the degradation process of Biobon s . However, implantation of chronOStInject was associated with a significantly higher rate of fibrous tissue formation. Cement resorption was mediated by macrophages in the chronOStInject group, while osteoclasts were the predominant cell type involved in degradation of Biobon s . Osteoblasts were found adjacent to residual cement in both groups. Conclusion: chronOStInject demonstrated osteoconductive properties, good biocompatibility and superior bioresorbability but none of the cements proved suitable for filling large cranial bony defects due to the high rate of fibrous tissue formation and insufficient bony regeneration. r 2004 European Association for Cranio-Maxillofacial Surgery
Journal of Biomedical Materials Research Part A, 2007
We investigated the histological and compressive properties of three different calcium phosphate cements (CPCs) using a sheep vertebral bone void model. One of the CPCs contained barium sulfate to enhance its radiopacity. Bone voids were surgically created in the lumbar region of 23 ovine spines-L3, L4, and L5 (n ¼ 69 total vertebral bodies)-and the voids were filled with one of the three CPCs. A fourth group consisted of whole intact vertebrae. Histologic evaluation was performed for 30 of the 69 vertebrae 2 or 4 months after surgery along with radiographic evaluation. Compressive testing was performed on 39 vertebrae 4 months after surgery along with micro-CT analysis. All three CPCs were biocompatible and extremely osteoconductive. Osteoclasts associated with adjacent bone formation suggest that each cement can undergo slow resorption and replacement by bone and bone marrow. Compressive testing did not reveal a significant difference in the ultimate strength, ultimate strain, and structural modulus, among the three CPCs and intact whole vertebrae. Micro-CT analysis revealed good osseointegration between all three CPCs and adjacent bone. The barium sulfate did not affect the CPCs biocompatibility or mechanical properties. These results suggest that CPC might be a good alternative to polymethylmethacrylate for selected indications.
Bioceramic cement in the filling of bone defects in rats
Acta Cirurgica Brasileira
To evaluate PBS ® MCIMMO cement in the filling of bone defects. Methods: Thirty-six adult male Wistar rats were divided into three groups of twelve individuals each (group 1, group 2 and group 3). In all groups, a bone failure in the femur was induced, 2.0 mm wide and 7.0 mm deep. In group 1, the PBS ® MCIMMO cement was applied to the bone defect produced and a titanium implant (CONNECTION ®) 1.5 mm thick and 6 mm long was installed. In group 2, only the PBS ® CIMMO cement was installed. In group 3, only bone failure was performed. Kruskal Wallis tests were performed to compare the mean area among the three groups. Results: In all comparisons, significance was observed for group 2 (p = 0.0014-0.0026). Conclusion: The PBS ® CIMMO cement induced bone neoformation, and integration between the newly formed bone, cement, and implant was observed.
Critical Defect Healing Assessment in Rat Calvaria Filled with Injectable Calcium Phosphate Cement
Journal of Functional Biomaterials, 2019
(1) Background: The tissue engineering field has been working to find biomaterials that mimic the biological properties of autogenous bone grafts. (2) Aim: To evaluate the osteoconduction potential of injectable calcium phosphate cement implanted in critical defects in rat calvaria. (3) Methods: In the calvarial bone of 36 rats, 7-mm diameter critical size defects were performed. Afterwards, the animals were randomly divided into three groups according to filler material: a blood clot group (BC), blood clot membrane group (BCM), and an injectable β-tricalcium phosphate group (HBS) cement group. After periods of 30 and 60 days, the animals were euthanized, the calvaria was isolated, and submitted to a decalcification process for later blades confection. Qualitative and quantitative analysis of the neoformed bone tissue were conducted, and histometric data were statistically analyzed. (4) Results: Sixty days post-surgery, the percentages of neoformed bone were 10.67 ± 5.57 in group BC, 16.71 ± 5.0 in group BCM, and 55.11 ± 13.20 in group HBS. The bone formation values in group HBS were significantly higher (p < 0.05) than in groups BC and BCM. (5) Conclusions: Based on these results, it can be concluded that injectable calcium phosphate cement is an osteoconductive material that can be used to fill bone cavities.
Of the in vivo behavior of calcium phosphate cements and glasses as bone substitutes
Acta Biomaterialia, 2008
The use of injectable self-setting calcium phosphate cements or soluble glass granules represent two different strategies for bone regeneration, each with distinct advantages and potential applications. This study compares the in vivo behavior of two calcium phosphate cements and two phosphate glasses with different composition, microstructure and solubility, using autologous bone as a control, in a rabbit model. The implanted materials were a-tricalcium phosphate cement (cement H), calcium sodium potassium phosphate cement (cement R), and two phosphate glasses in the P 2 O 5 -CaO-Na 2 O and P 2 O 5 -CaO-Na 2 O-TiO 2 systems. The four materials were osteoconductive, biocompatible and biodegradable. Radiological and histological studies demonstrated correct osteointegration and substitution of the implants by new bone. The reactivity of the different materials, which depends on their solubility, porosity and specific surface area, affected the resorption rate and bone formation mainly during the early stages of implantation, although this effect was weak. Thus, at 4 weeks the degradation was slightly higher in cements than in glasses, especially for cement R. However, after 12 weeks of implantation all materials showed a similar degradation degree and promoted bone neoformation equivalent to that of the control group.
Use of a calcium phosphate matrix as a temporary cast for bony defect repair: a pilot study
Journal of Materials Science - J MATER SCI, 2003
The bony repair effect of different Calcium Phosphate Bone Cements was tested in a dog model. Seven different formulations were synthesized and tested on their biocompatibility, osseoconduction and biodegradability. Three dogs were used in this pilot study, in each dog 4 cranial, circular defects were made with a critical size diameter of 12 mm. Autologous bone was used as a control. The dogs were sacrificed after 6 months. Mineral phase analysis showed a reaction of the cements to form a more or less crystalline calciumhydroxyapatite. Histologic evaluation revealed that the presence of the cements stimulated the formation of a thin bone layer on the cranial and caudal side of each defect. The cements did not evoke an inflammatory reaction. Two formulations showed extensive bone formation.
Bone healing in porous implants: a histological and histometrical comparative study on sheep
Journal of materials science. Materials in medicine, 2000
Tissue integration in four types of porous implant materials (Interpore 200 or Corallin hydroxyapatite, hydroxyapatite blocks, hydroxyapatite granules and polymethylmethacrylate) was evaluated in vivo. Porous blocks measuring 20 mm x 10 mm x 8 mm were implanted in mandibles and iliac crests of sheep. Bone healing in porous blocks was studied at 2 and 6 months after implantation. The behavior of the material itself was also analyzed. Histological and histomorphometrical analysis revealed bone healing depending upon healing time and material. On the basis of analysis of variance, differences in amounts of bone ingrowth at 2 and 6 months were statistically significant (p=0.0039 in mandible; p=0.0351 in iliac crest). The longer the time span, the more mineralized tissues were observed in the specimen. Our data confirmed that hydroxyapatite has osteoconductive capacities. Porous PMMA was found to be biocompatible, but it showed less bonegrowth within the pores. Interpore 200, which had t...
Short-term implantation effects of a DCPD-based calcium phosphate cement
Biomaterials, 1998
Calcium phosphate cements can be handled in paste form and set in a wet medium after precipitation of calcium phosphate crystals in the implantation site. Depending on the products entering into the chemical reaction leading to the precipitation of calcium phosphates, different phases can be obtained with different mechanical properties, setting times and injectability. We tested a cement composed of a powder, containing-tricalcium phosphate (-TCP) and sodium pyrophosphate mixed with a solution of phosphoric and sulphuric acids. The cement set under a dicalcium phosphate dihydrate (DCPD)-based matrix containing-TCP particles. This was injected with a syringe into a defect drilled in rabbit condyles, the control being an identical defect left empty in the opposite condyle. The condyles were analysed histologically 2, 6 and 18 weeks after implantation. After injection into the bone defect the cement set and formed a porous calcium phosphate structure. Two different calcium phosphate phases with different solubility rates could be identified by scanning electron microscopy (SEM) observation. The less-soluble fragments could be degraded by cell phagocytosis in cell compartments of low pH or integrated in the newly formed bone matrix. The degradation rate of the material was relatively high but compatible with the ingrowth of bone trabeculae within the resorbing material. The ossification process was different from the creeping substitution occurring at the ceramic contact. Bone did not form directly at the cement surface following the differentiation of osteoblasts at the material surface. The trabeculae came to the material surface from the edges of the implantation site. Bone formation in the implantation site was significantly higher than in the control region during the first week of implantation. In conclusion, this material set in situ was well tolerated, inducing a mild foreign-body reaction, which did not impair its replacement by newly formed bone within a few weeks.