WorldWideScience

Sample records for bone cement additives

  1. Investigation of an effervescent additive as porogenic agent for bone cement macroporosity.

    Science.gov (United States)

    Hesaraki, Saeed; Sharifi, Davood

    2007-01-01

    Calcium phosphate cements (CPCs) are biocompatible and osteoconductive materials used in dental, craniofacial and orthopaedic applications. One of the most important advantages of these materials is their replacement with bone followed by resorption. Already several attempts have been made to improve the resorption behaviour of calcium phosphate cements by increasing the porosity of the material. In this investigation a mixture of NaHCO(3) and citric acid monohydrate was added to the apatite cement component as an effervescent additive for producing interconnected macropores into the cement matrix. Mercury intrusion porosimetry was employed to determine pore volume and pore size distribution in the calcium phosphate cement (CPC) samples. Results showed that addition of only 10 wt % of the effervescent additive (based on the cement powder) to the CPC components lead to producing about 20 V % macropores (with the size of 10 to 1000 mum) into the cement structure. The setting time was measured in an incubator at 37 degrees C and decreased from 40 min for additive-free CPC to about 14 min for CPC containing effervescent additive. Other properties of the CPCs such as compressive strength, phase composition, microstructure morphology and dissolution behavior were evaluated after immersing them in a simulated body fluid solution. The results showed that the rate of formation of poor crystalline apatite phase have been improved by production of macroporosity into the cement matrix. PMID:17264385

  2. The effect of oligo(trimethylene carbonate) addition on the stiffness of acrylic bone cement.

    Science.gov (United States)

    Persson, Cecilia; López, Alejandro; Fathali, Hoda; Hoess, Andreas; Rojas, Ramiro; Ott, Marjam Karlsson; Hilborn, Jöns; Engqvist, Håkan

    2016-01-01

    With the increasing elderly population an increase in the number of bony fractures associated to age-related diseases such as osteoporosis also follows. The relatively high stiffness of the acrylic bone cements used in these patients has been suggested to give raise to a suboptimal load distribution surrounding the cement in vivo, and hence contribute to clinical complications, such as additional fractures. The aim of this study was to develop a low-modulus bone cement, based on currently used, commercially available poly(methyl methacrylate) (PMMA) cements for vertebroplasty. To this end, acrylate end-functionalized oligo(trimethylene carbonate) (oTMC) was incorporated into the cements, and the resulting compressive mechanical properties were evaluated, as well as the cytotoxic and handling properties of selected formulations. Sixteen wt%oTMC was needed in the vertebroplastic cement Osteopal V to achieve an elastic modulus of 1063 MPa (SD 74), which gave a corresponding compressive strength of 46.1 MPa (SD 1.9). Cement extracts taken at 1 and 12 hours gave a reduced MG-63 cell viability in most cases, while extracts taken at 24 hours had no significant effect on cell behavior. The modification also gave an increase in setting time, from 14.7 min (SD 1.7) to 18.0 min (SD 0.9), and a decrease in maximum polymerization temperature, from 41.5°C (SD 3.4) to 30.7°C (SD 1.4). While further evaluation of other relevant properties, such as injectability and in vivo biocompatibility, remains to be done, the results presented herein are promising in terms of approaching clinically applicable bone cements with a lower stiffness. PMID:26727581

  3. The effect of unsaturated fatty acid and triglyceride oil addition on the mechanical and antibacterial properties of acrylic bone cements.

    Science.gov (United States)

    Persson, Cecilia; Robert, Elise; Carlsson, Elin; Robo, Céline; López, Alejandro; Godoy-Gallardo, Maria; Ginebra, Maria-Pau; Engqvist, Håkan

    2015-09-01

    Acrylic bone cements have an elastic modulus several times higher than the surrounding trabecular bone. This has been hypothesized to contribute to certain clinical complications. There are indications that the addition of specific fatty acids and triglyceride oils may reduce the elastic modulus of these types of cements. Some of these additives also appear to have inherent antibiotic properties, although this has never been evaluated in bone cements. In this study, several types of fatty acids and triglyceride oils were evaluated for use in acrylic bone cements. Their mechanical properties were evaluated under uniaxial compression testing and selected cements were then further characterized in terms of microstructure, handling and antibacterial properties using scanning electron microscopy, polymerization temperature measurements, agar diffusion tests and bactericidal activity assays of cement extracts. It was found that any of the evaluated fatty acids or triglyceride oils could be used to tailor the stiffness of acrylic bone cements, although at varying concentrations, which also depended on the type of commercial base cement used. In particular, the addition of very small amounts of linoleic acid (agar diffusion test as well as demonstrating 100% bactericidal activity against the same strain. PMID:25876889

  4. Investigating calcium polyphosphate addition to a conventional calcium phosphate cement for bone-interfacing applications

    Science.gov (United States)

    Krausher, Jennifer Lynn

    Calcium phosphate cements (CPCs) are of great interest in bone regeneration applications because of their biocompatibility and osteoconductivity, and as delivery vehicles for therapeutics; however, delivery applications have been limited by adverse interactions between therapeutics and the cement setting reaction. Amorphous calcium polyphosphate (CPP) yields a biodegradable material with a demonstrated drug delivery capacity following appropriate processing. The incorporation of drug-loaded CPP into a CPC is under consideration as a method of minimizing adverse interactions and extending drug release. This thesis represents the first investigation into the effects of CPP addition on the properties, setting and antibiotic release profile of a conventional apatitic calcium phosphate cement. As-made, gelled and vancomycin-loaded CPP particulate were added to the powder component of a conventional dicalcium phosphate/tetracalcium phosphate CPC. The setting behaviour, set properties and microstructure of the resulting CPP-CPCs were evaluated with setting time testing (Gilmore needle method), pH testing, mechanical testing, SEM imaging, XRD and FTIR analysis. In vitro degradation and elution behaviour were evaluated by monitoring calcium release (atomic absorbance spectroscopy), mechanical strength and vancomycin release (UV-visual spectrophotometry). CPP addition was found to increase the setting time, reduce the mechanical strength and inhibit the conversion of the CPC starting powders to the set apatitic phase. The most likely mechanism for the observed effect of CPP addition was the adsorption of polyphosphate chains on the particle surfaces, which would inhibit the dissolution of the starting powders and the conversion of apatite precursor phases to apatite, leading to reduced mechanical properties. The detrimental effects of CPP were reduced by limiting the CPP fraction to less than a few weight per cent and increasing the size of the CPP particulate. CPP

  5. Formation of interconnected macropores in apatitic calcium phosphate bone cement with the use of an effervescent additive.

    Science.gov (United States)

    Hesaraki, S; Moztarzadeh, F; Sharifi, D

    2007-10-01

    Calcium phosphate cements (CPCs) can be considered as good candidate for bone tissue engineering because they can be resorbed and take part in the bone remodeling process. Several efforts have been made into improve the resorption rate of the calcium phosphate cement by introducing macropores to the cement matrix. In this investigation a simple and effective method has been presented based on the addition of various amounts of an effervescent agent to the calcium phosphate cement components. The effervescent agent was a mixture of sodium hydrogen carbonate, NaHCO(3) (that was added to the powder phase), and citric acid monohydrate, C(6)H(8)O(7).H(2)O (that was dissolved in the liquid phase). The obtained macroporous samples were characterized by Fourier transform infrared spectrometer, X-ray diffraction, and scanning electron microscopy techniques at 4 h after setting and 3 days after soaking in a special simulated body fluid solution named Hank's balanced salt solution. Mercury intrusion porosimetry was also employed for characterizing the pore volume and pore size distribution in the cement structure. Results showed that the rate of conversion of staring reactant to the apatite phase and the apatite chemistry were significantly changed by using the additive in the cement components. Also both the pore volume and pore size were changed by varying both the amount of effervescent additive and the powder to liquid ratio. PMID:17380498

  6. Calcium phosphate holmium-166 ceramic to addition in bone cement: synthesis and characterization

    International Nuclear Information System (INIS)

    Spine metastases are a common and painful complication of cancer. The treatment often consists of bone cement injection (vertebroplasty or kyphoplasty) within vertebral body for vertebrae stabilization, followed by external beam radiation therapy. Recently, researchers introduced the concept of radioactive bone cement for spine tumors therapy. Then, investigations about bioactive and radioactive materials became interesting. In this study, we present the synthesis of calcium phosphate incorporated holmium (CaP-Ho) via sol-gel technique, and its characterization by XRD, FT-IR, NA and SEM. Results showed a multiphasic bioceramic composed mainly of hydroxyapatite, β-tricalcium phosphate, holmium phosphate and traces of calcium pyrophosphate. Furthermore, the nuclide Ho-166 was the major radioisotope produced. Despite that, the radioactive bioceramic CaP-166Ho must be investigated in clinical trials to assure its efficacy and safety on spine tumors treatment (author)

  7. Calcium phosphate holmium-166 ceramic to addition in bone cement: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Donanzam, Blanda A.; Campos, Tarcisio P.R., E-mail: campos@nuclear.ufmg.b [Universidade do Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Nuclear; Dalmazio, Ilza; Valente, Eduardo S., E-mail: id@cdtn.b, E-mail: valente@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Spine metastases are a common and painful complication of cancer. The treatment often consists of bone cement injection (vertebroplasty or kyphoplasty) within vertebral body for vertebrae stabilization, followed by external beam radiation therapy. Recently, researchers introduced the concept of radioactive bone cement for spine tumors therapy. Then, investigations about bioactive and radioactive materials became interesting. In this study, we present the synthesis of calcium phosphate incorporated holmium (CaP-Ho) via sol-gel technique, and its characterization by XRD, FT-IR, NA and SEM. Results showed a multiphasic bioceramic composed mainly of hydroxyapatite, {beta}-tricalcium phosphate, holmium phosphate and traces of calcium pyrophosphate. Furthermore, the nuclide Ho-166 was the major radioisotope produced. Despite that, the radioactive bioceramic CaP-{sup 166}Ho must be investigated in clinical trials to assure its efficacy and safety on spine tumors treatment (author)

  8. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available BACKGROUND: Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth. MATERIALS AND METHODS: The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests. RESULTS: The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony

  9. Evaluation of colloidal silica suspension as efficient additive for improving physicochemical and in vitro biological properties of calcium sulfate-based nanocomposite bone cement.

    Science.gov (United States)

    Borhan, Shokoufeh; Hesaraki, Saeed; Ahmadzadeh-Asl, Shaghayegh

    2010-12-01

    In the present study new calcium sulfate-based nanocomposite bone cement with improved physicochemical and biological properties was developed. The powder component of the cement consists of 60 wt% α-calcium sulfate hemihydrate and 40 wt% biomimetically synthesized apatite, while the liquid component consists of an aqueous colloidal silica suspension (20 wt%). In this study, the above mentioned powder phase was mixed with distilled water to prepare a calcium sulfate/nanoapatite composite without any additive. Structural properties, setting time, compressive strength, in vitro bioactivity and cellular properties of the cements were investigated by appropriate techniques. From X-ray diffractometer analysis, except gypsum and apatite, no further phases were found in both silica-containing and silica-free cements. The results showed that both setting time and compressive strength of the calcium sulfate/nanoapatite cement improved by using colloidal silica suspension as cement liquid. Meanwhile, the condensed phase produced from the polymerization process of colloidal silica filled the micropores of the microstructure and covered rodlike gypsum crystals and thus controlled cement disintegration in simulated body fluid. Additionally, formation of apatite layer was favored on the surfaces of the new cement while no apatite precipitation was observed for the cement prepared by distilled water. In this study, it was also revealed that the number of viable osteosarcoma cells cultured with extracts of both cements were comparable, while silica-containing cement increased alkaline phosphatase activity of the cells. These results suggest that the developed cement may be a suitable bone filling material after well passing of the corresponding in vivo tests. PMID:20972610

  10. Calcium phosphate cements properties with polymers addition

    International Nuclear Information System (INIS)

    Calcium phosphate cements (CPC) have attracted great interest to use in orthopedics and dentistry as replacements for damaged parts of the skeletal system, showing good biocompatibility and osseointegration, allowing its use as bone graft. Several studies have shown that the addition of polymer additives have a strong influence on the cement properties. The low mechanical strength is the main obstacle to greater use of CPC as an implant material. The objective of this study was to evaluate properties of a cement based on α-tricalcium phosphate (α-TCP), added polymers. PVA (10%, 8%, 6%), sodium alginate (2%) and polyacrylate ammonia (3%), all in weight, were added to the synthesized α-TCP powder. The samples were molded and evaluated for density, porosity in vitro test (Simulated Body Fluid), crystalline phases and mechanical strength. The results show increased the mechanical properties of the cement when added these polymers

  11. Stiffness and strength of composite acrylic bone cements

    Directory of Open Access Journals (Sweden)

    I. Knets

    2007-01-01

    Full Text Available Purpose: Different acrylic bone cements based upon PMMA-MMA system are applicable for implant fixation inbone tissue. The aim of present study is the optimisation of the structure of some new bone acrylic cements madeon the basis of PMMA-ethylmethacrylate-triethyleneglycoldimethacrylate and bone cements having additives (HAand radio pacifier, and the finding of the effect of these modifications on the flexural strength and stiffness.Design/methodology/approach: Different new bone cements on the basis of PMMA-EMA-TEGDMA system(ABC were developed experimentally. The stiffness and strength of the samples of these modified cements weredetermined in the special three point bending equipment.Findings: A comparison of the flexural properties of new PMMA-EMA-TEGDMA cements and commercialavailable PMMA-MMA cement showed that commercial bone cement had larger values of ultimate strengthand modulus of elasticity, but the difference is not very important. As concerns the polymerisation peaktemperature, then there is a significant difference between commercial PMMA-MMA cement (~ 800C andPMMA-EMA-TEGDMA modified cements (50 – 600C. The introduction of 10% and 18% of HA into solidphase does not influence essentially strength and modulus of elasticity of the PMMA-EMA-TEGDMA bonecements. The introduction of radio pacifier BaSO4 into bone cement leads to flexural strength diminishing.Low polymerisation peak temperature and appropriate mechanical properties of bone cements developed allowsregarding new 3-D structure acrylic bone cements as promising biomaterials.Research limitations/implications: It is supposed to carry out animal testing to learn more about reaction ofmodified implanted material on the biological environment.Practical implications: The new materials could be efficiently used as bone cements because they will notdamage surrounding biological tissue during curing.Originality/value: Paper is providing the new information about possibilities to

  12. The use of bone cement for the localized, controlled release of the antibiotics vancomycin, linezolid, or fusidic acid: effect of additives on drug release rates and mechanical strength.

    Science.gov (United States)

    Jackson, John; Leung, Fay; Duncan, Clive; Mugabe, Clement; Burt, Helen

    2011-04-01

    Bone cement containing antibiotics is commonly used to treat orthopedic related infections. However, effective treatment (especially of resistant bacteria, methacillin-resistant Staphylococcus aureus (MRSA)) is compromised by very low levels of drug release so that typically less than 10% of loaded drug is released over a 6-week period. The objective of this study was to investigate the effect of incorporation of water soluble excipients (polyethylene glycol, sodium chloride, or dextran) into antibiotic-loaded cement on mechanical strength and drug release properties. Poly(methyl methylacrylate) cement implants containing various amounts of drug (vancomycin, linezolid or fusidic acid (all MRSA active)) and excipients were cast in the form of beads or films and characterized using differential scanning calorimetry. Mechanical strength as assessed by Young's modulus was determined by thermo-mechanical analysis. Drug release was measured by incubation in phosphate buffered saline with analysis by HPLC methods. The inclusion of sodium chloride up to 20% w/w caused only minor reductions in Young's modulus. Vancomycin and linezolid released very slowly from unmodified bone cement beads (less than 3% released by 4 weeks) whereas fusidic acid released more quickly (approximately 8% released by 4 weeks). The inclusion of sodium chloride or dextran in bone cement resulted in major increases in the release rate of vancomycin, linezolid and fusidic acid. These studies support the inclusion of sodium chloride and dextran in bone cement to increase the release rate of vancomycin, linezolid, or fusidic acid without compromising the mechanical strength of the composite material. PMID:25788111

  13. Preliminary study using pulsating water jet for bone cement demolition

    OpenAIRE

    S. Hloch; Kloc, J.; Foldyna, J.; Pude, F.; Smolko, I.; M. Zeleňák; Sitek, L. (Libor); Hvizdoš, P.; Monka, P.; Monková, K.; Kozak, D.; A. Stoić; A. Sedmak; Milosevic, M; Lehocká, D.

    2015-01-01

    The paper deals with the study of using the selective property of ultrasonic pulsating water jet for the disintegration of bone cement which creates the interface between femoral stem and trabecular bone tissue. For investigation, commercial bone cements were used. Bone cements were tested by nanoindentation in order to review their mechanical properties. A representative sample Palacos R+G was selected for disintegration of bone cement. Bone cements samples fixed between two plexiglass...

  14. Acrylic Bone Cements Modified with Starch

    OpenAIRE

    Krilova, V; Vītiņš, V

    2010-01-01

    The successful result of restorative and replacement surgical operation depends significantly on properties of used bone cement. Acrylic bone cements are usually based on methylmethacrylate polymer, while monomer polymerization begins after mixing of components in mixing device and terminates in living tissue. Polymerization of methylmethacrylate is exothermic process, and temperature increase might cause tissue necrosis with concomitant implant aseptic loosening. Developed non-ionogenic and ...

  15. Characterization of cement composites with mineral additives

    OpenAIRE

    Korat, Lidija

    2015-01-01

    Doctoral dissertation is aimed at characterizing cement composites with mineral additives representing the industrial waste material (fly ash, granulated blast furnace slag and biomass fly ash). Their usage can replace high cement shares in individual cases and is, however, favourable due to the production costs reduction and environment burden decrease, including the decreased emission of greenhouse gases as well as lower energy use. Cement composites (in fresh or hardened state)...

  16. Preclinical evaluation of strontium-containing bioactive bone cement

    International Nuclear Information System (INIS)

    Strontium (Sr) has become more attractive for orthopaedic applications as they can simultaneously stimulate bone formation and prevent bone loss. A Sr-containing bioactive bone cement (Sr-BC) has been designed to fix osteoporotic bone fracture. Sr is a trace element, so the safety of containing Sr is concerned when Sr-BC is implanted in human body. The preclinical assessment of biocompatibility of Sr-BC was conducted according to ISO 10993 standards. MTT assay showed that this bioactive bone cement was non-toxic to mouse fibroblasts, and it met the basic requirement for the orthopaedic implant. The three independent genetic toxicity studies including Ames, chromosome aberration and bone marrow micronucleus assays demonstrated absence of genotoxic components in Sr-BC, which reassured the safety concerns of this novel bone cement. The muscle implantation results in present study were also encouraging. The acute inflammation around the cement was observed at 1 week post-implantation; however, no significant difference was observed between control and Sr-BC groups. These responses may be attributed to the presence of the foreign body, but the tissue healed after 12 weeks implantation. In summary, the above preclinical results provide additional assurance for the safety of this implant. Sr-BC can be used as a potential alternative to the traditional bone cement. - Highlights: • Strontium-containing bioactive bone cement (Sr-BC) was designed. • The biocompatibility of Sr-BC was evaluated according ISO 10993 standards. • Preclinical results provide additional assurance for the safety of Sr-BC

  17. Preparation and characterization of an injectable bone cement

    International Nuclear Information System (INIS)

    Self-setting calcium phosphate bone cements (CPBC) are attractive materials for bone defect reconstruction in non-stress-bearing areas because they can be molded into shape during implantation beside their excellent osteoconductivity and bone-replacement capability. The objective of this study is to locally produce and characterize bone cement made of tricalcium phosphate, dicalcium phosphate dihydrate, hydroxyapatite and calcium carbonate. An aqueous medium containing 3% disodium hydrogen phosphate solution was provided as the accelerator to make it a self-setting. The liquid to powder ratio was 0.35 ml/g. The paste was kneaded with the aid of a spatula between each addition to produce a paste of workable consistency. After a total mixing time of two minutes, the paste was firmly loaded into syringe. Injection was performed by a 10 ml syringe with 1.5 mm needle diameter into a mold to form cylindrical specimens of 6 mm radius and 12 mm height. Samples were soaked in simulated body fluid (SBF) for bioactivity study. X-ray diffraction (XRD) is used to analyze the phase of the precipitated cement. Mechanical properties were characterized by compressive test. The results showed that the bone cement successfully produced in-situ. Scanning electron micrograph showed that the cement was porous with size around 50 mm and the pores were almost interconnected. Studies on the setting characteristics and the compressive strength indicated that the properties were within the range of interest. (Author)

  18. Mechanical properties of femoral cortical bone following cemented hip replacement.

    Science.gov (United States)

    Ni, G X; Lu, W W; Chiu, P K Y; Wang, Y; Li, Z Y; Zhang, Y G; Xu, B; Deng, L F; Luk, K D K

    2007-11-01

    Femoral bone remodeling following total hip replacement is a big concern and has never been examined mechanically. In this study, six goats underwent unilateral cemented hip hemiarthroplasty with polymethyl methacrylate (PMMA) bone cement. Nine months later animals were sacrificed, and the femoral cortical bone slices at different levels were analysed using microhardness testing and microcomputed tomography (micro-CT) scanning. Implanted femurs were compared to contralateral nonimplanted femurs. Extensive bone remodeling was demonstrated at both the proximal and middle levels, but not at the distal level. Compared with the nonimplanted side, significant decreases were found in the implanted femur in cortical bone area, bone mineral density, and cortical bone hardness at the proximal level, as well as in bone mineral density and bone hardness at the middle level. However, no significant difference was observed in either variable for the distal level. In addition, similar proximal-to-distal gradient changes were revealed both in cortical bone microhardness and bone mineral density. From the mechanical point of view, the results of the present study suggested that stress shielding is an important mechanical factor associated with bone adaptation following total hip replacement. PMID:17506504

  19. Antimicrobial activity of bone cements embedded with organic nanoparticles

    Directory of Open Access Journals (Sweden)

    Perni S

    2015-10-01

    Full Text Available Stefano Perni,1,2 Victorien Thenault,1 Pauline Abdo,1 Katrin Margulis,3 Shlomo Magdassi,3 Polina Prokopovich1,2 1School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK; 2Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; 3Casali Institute, Institute of Chemistry, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, IsraelAbstract: Infections after orthopedic surgery are a very unwelcome outcome; despite the widespread use of antibiotics, their incidence can be as high as 10%. This risk is likely to increase as antibiotics are gradually losing efficacy as a result of bacterial resistance; therefore, novel antimicrobial approaches are required. Parabens are a class of compounds whose antimicrobial activity is employed in many cosmetic and pharmaceutical products. We developed propylparaben nanoparticles that are hydrophilic, thus expanding the applicability of parabens to aqueous systems. In this paper we assess the possibility of employing paraben nanoparticles as antimicrobial compound in bone cements. The nanoparticles were embedded in various types of bone cement (poly(methyl methacrylate [PMMA], hydroxyapatite, and brushite and the antimicrobial activity was determined against common causes of postorthopedic surgery infections such as: Staphylococcus aureus, methicillin-resistant S. aureus, Staphylococcus epidermidis, and Acinetobacter baumannii. Nanoparticles at concentrations as low as 1% w/w in brushite bone cement were capable of preventing pathogens growth, 5% w/w was needed for hydroxyapatite bone cement, while 7% w/w was required for PMMA bone cement. No ­detrimental effect was determined by the addition of paraben nanoparticles on bone cement compression strength and cytocompatibility. Our results demonstrate that paraben nanoparticles can be encapsulated in bone cement, providing concentration-dependent antimicrobial

  20. Regulatory perspective on characterization and testing of orthopedic bone cements.

    Science.gov (United States)

    Demian, H W; McDermott, K

    1998-09-01

    This paper provides a general regulatory background of acrylic bone cements, chemical composition information on several commercially available bone cements, physical and chemical methods of analyses, mechanical test methods, and risks and failure mechanisms of acrylic bone cements. Suggestions and recommendations presented in Tables 2 and 3 are not mandatory requirements but reflect data and methodologies which the FDA's Orthopedic Devices Branch (ORDB) believes to be acceptable to evaluate most pre-clinical data. FDA may require information in addition to that contained in this paper. In some instances, a sponsor may be able to sufficiently justify the omission of some tests. Although this paper describes certain administrative requirements, it does not take the place of the requirements contained in Title 21 of the Code of Federal Regulations (21 CFR) Parts 801, 807, 812, and 814 or those found in the statute. PMID:9830987

  1. The effect of cement creep and cement fatigue damage on the micromechanics of the cement-bone interface.

    Science.gov (United States)

    Waanders, Daan; Janssen, Dennis; Mann, Kenneth A; Verdonschot, Nico

    2010-11-16

    The cement-bone interface provides fixation for the cement mantle within the bone. The cement-bone interface is affected by fatigue loading in terms of fatigue damage or microcracks and creep, both mostly in the cement. This study investigates how fatigue damage and cement creep separately affect the mechanical response of the cement-bone interface at various load levels in terms of plastic displacement and crack formation. Two FEA models were created, which were based on micro-computed tomography data of two physical cement-bone interface specimens. These models were subjected to tensile fatigue loads with four different magnitudes. Three deformation modes of the cement were considered: 'only creep', 'only damage' or 'creep and damage'. The interfacial plastic deformation, the crack reduction as a result of creep and the interfacial stresses in the bone were monitored. The results demonstrate that, although some models failed early, the majority of plastic displacement was caused by fatigue damage, rather than cement creep. However, cement creep does decrease the crack formation in the cement up to 20%. Finally, while cement creep hardly influences the stress levels in the bone, fatigue damage of the cement considerably increases the stress levels in the bone. We conclude that at low load levels the plastic displacement is mainly caused by creep. At moderate to high load levels, however, the plastic displacement is dominated by fatigue damage and is hardly affected by creep, although creep reduced the number of cracks in moderate to high load region. PMID:20692663

  2. Pulmonary bone cement embolism: CT angiographic evaluation with material decomposition using gemstone spectral imaging.

    Science.gov (United States)

    Huh, Sun; Lee, Heon

    2014-01-01

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition. PMID:25053903

  3. Pulmonary bone cement embolism: CT angiographic evaluation with material decomposition using gemstone special imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Sun; Lee, Heon [Dept. of Radiology, Soonchunhyang University Hospital Bucheon, Bucheon (Korea, Republic of)

    2014-08-15

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition.

  4. Pulmonary bone cement embolism: CT angiographic evaluation with material decomposition using gemstone special imaging

    International Nuclear Information System (INIS)

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition.

  5. Disintegration of Bone Cement by Continuous and Pulsating Water Jet

    OpenAIRE

    S. Hloch; Foldyna, J.; Sitek, L. (Libor); M. Zeleňák; Hlaváček, P.; Hvizdoš, P.; Kloc, J.; Monka, P.; Monková, K.; Kozak, D.; Magurová, D.

    2013-01-01

    The paper deals with the study of using continuous water jet and ultrasonic pulsating water jet for bone cement disintegration. Bone-cement Pallacos R+G (manually mixed) was disintegrated ex-vivo. Mechanical properties of the bone cement were determined by nano-indentation. Factors employed in evaluation were pressure (40, 80, 120) MPa and traverse speed for continuous water jet, pressure (8, 10, 12, 14, 16, 20) MPa and orifice type (flat, circular) for ultrasonic pulsating water jet. Depth p...

  6. Preparation and Characterization of Injectable Brushite Filled-Poly (Methyl Methacrylate Bone Cement

    Directory of Open Access Journals (Sweden)

    Lucas C. Rodriguez

    2014-09-01

    Full Text Available Powder-liquid poly (methyl methacrylate (PMMA bone cements are widely utilized for augmentation of bone fractures and fixation of orthopedic implants. These cements typically have an abundance of beneficial qualities, however their lack of bioactivity allows for continued development. To enhance osseointegration and bioactivity, calcium phosphate cements prepared with hydroxyapatite, brushite or tricalcium phosphates have been introduced with rather unsuccessful results due to increased cement viscosity, poor handling and reduced mechanical performance. This has limited the use of such cements in applications requiring delivery through small cannulas and in load bearing. The goal of this study is to design an alternative cement system that can better accommodate calcium-phosphate additives while preserving cement rheological properties and performance. In the present work, a number of brushite-filled two-solution bone cements were prepared and characterized by studying their complex viscosity-versus-test frequency, extrusion stress, clumping tendency during injection through a syringe, extent of fill of a machined void in cortical bone analog specimens, and compressive strength. The addition of brushite into the two-solution cement formulations investigated did not affect the pseudoplastic behavior and handling properties of the materials as demonstrated by rheological experiments. Extrusion stress was observed to vary with brushite concentration with values lower or in the range of control PMMA-based cements. The materials were observed to completely fill pre-formed voids in bone analog specimens. Cement compressive strength was observed to decrease with increasing concentration of fillers; however, the materials exhibited high enough strength for consideration in load bearing applications. The results indicated that partially substituting the PMMA phase of the two-solution cement with brushite at a 40% by mass concentration provided the best

  7. The functional performance of orthopaedic bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Prendergast, P.J. [Trinity Coll., Dublin (Ireland). Dept. of Mechanical Engineering

    2001-07-01

    This paper presents a summary of our work on the functional behavior of polymethylmethacrylate as a fixation material for load-bearing implants. Experimental tests on models of hip reconstructions have shown that damage accumulation, in the form of growth of numerous microcracks, occurs in cement-fixated orthopaedic implants. To predict failure due to damage accumulation, fatigue tests of hand-mixed and vacuum-mixed cement are used to determine a relationship between the probability-of-failure, stress, and porosity of the cement. This relationship is then applied to the comparative analysis of orthopaedic implants using finite element analysis. Two implant systems are considered: femoral hip prostheses and glenoid replacement prostheses. It is shown how the complex and intricate stress patterns in the polymethylmethacrylate cement 'mantles' can be analyzed in terms of the probability-of-failure. This allows comparison of implants for pre-clinical testing purposes. The results complement those obtained from clinical studies where subsidence of the implant correlates with implant loosening [Karrholm et al. J. Bone Jt. Surg. Vol. 76B (1994) 912-916]. If subsidence is due to creep, then a correlation between damage accumulation and creep should exist. A basis for such a correlation in polymethylmetacrylate is proposed that links clinical findings of subsidence with our results with regard to damage accumulation. (orig.)

  8. Development and clinical trial of a novel bioactive bone cement

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Strontium(Sr)and related compounds have become more attractive in the prevention and treatment of osteoporosis.Previously,we developed a novel bioactive bone cement which is mainly composed of strontium-containing hydroxyapatite(Sr-HA)filler and bisphenol A diglycidylether dimethacrylate(Bis-GMA)resin.This bone cement is superior to conventional polymethylmethacrylate (PMMA)bone cement in bioactivity,biocompatibility,and osseointegration.It also has shown sufficient mechanical strength properties for its use in percutaneous vertebroplasty(PVP)and total hip replacement(THR).In this paper,we review the in vitro,in vivo and clinical evidence for the effectiveness of this bioactive bone cement.

  9. Chemical and physical properties of bone cement for vertebroplasty

    Directory of Open Access Journals (Sweden)

    Po-Liang Lai

    2013-08-01

    Full Text Available Vertebral compression fracture is the most common complication of osteoporosis. It may result in persistent severe pain and limited mobility, and significantly impacts the quality of life. Vertebroplasty involves a percutaneous injection of bone cement into the collapsed vertebrae by fluorescent guide. The most commonly used bone cement in percutaneous vertebroplasty is based on the polymerization of methylmethacrylate monomers to polymethylmethacrylate (PMMA polymers. However, information on the properties of bone cement is mostly published in the biomaterial sciences literature, a source with which the clinical community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the physical properties of PMMA. The effects of altering the portions and contents of monomer liquid and polymer powders on the setting time, polymerization temperature, and compressive strength of the cement are also discussed. This information will allow spine surgeons to manipulate bone cement characteristics for specific clinical applications and improve safety.

  10. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

    Science.gov (United States)

    Race, Amos; Miller, Mark A; Mann, Kenneth A

    2008-10-20

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models. PMID:18774136

  11. The effect of mixing on gentamicin release from polymethylmethacrylate bone cements

    NARCIS (Netherlands)

    Neut, D; van de Belt, H; van Horn, [No Value; van der Mei, HC; Busscher, HJ

    2003-01-01

    We compared the release of gentamicin from 6 different commercially available, antibiotic-loaded PMMA bone cements used for vacuum- and hand-mixed cement using a Cemvac vacuum mixing system. We also measured the release of gentamicin after manual addition of the antibiotic to different commercial, u

  12. Low-modulus PMMA bone cement modified with castor oil

    OpenAIRE

    López, Alejandro; Hoess, Andreas; Thersleff, Thomas; Ott, Marjam; Engqvist, Håkan; Persson, Cecilia

    2011-01-01

    Some of the current clinical and biomechanical data suggest that vertebroplasty causes the development of adjacent vertebral fractures shortly after augmentation. These findings have been attributed to high injection volumes as well as high Young’s moduli of PMMA bone cements compared to that of the osteoporotic cancellous bone. The aim of this study was to evaluate the use of castor oil as a plasticizer for PMMA bone cements. The Young’s modulus, yield strength, maximum polymerization temper...

  13. Microbial analyses of cement and grouting additives

    Energy Technology Data Exchange (ETDEWEB)

    Hallbeck, L.; Jaegevall, S.; Paeaejaervi, A.; Rabe, L.; Edlund, J.; Eriksson, S. [Microbial Analytics Sweden AB, Moelnlycke (Sweden)

    2012-01-15

    During sampling in the ONKALO tunnel in 2006, heavy growth of a slimy material was observed in connection with grouting. It was suggested to be microbial growth on organic additives leaching from the grout. Two sampling campaigns resulted in the isolation of several aerobic bacterial strains. Some of these strains were used in biodegradation studies of three solid cement powders, eight liquid grout additives, and six plastic drainage materials. Degradation was also studied using ONKALO groundwaters as inoculums. The isolated strains were most closely related to hydrocarbon-degrading microorganisms. The biodegradation of seven of the products was tested using microorganisms isolated from the ONKALO slime in 2006; none of these strains could degrade the tested products. When ONKALO drillhole groundwaters were used as inoculums in the degradation studies, it was demonstrated that Structuro 111X, Mighty 150, and Super-Parmix supported growth of the groundwater microorganisms. Structuro 111X is a polycarboxylate condensate while Mighty 150 and Super-Parmix are condensates with formaldehyde and naphthalene. Some of the isolated microorganisms belonged to the genus Pseudomonas, many strains of which can degrade organic molecules. None of the plastic drainage materials supported growth during the degradation studies. Microorganisms were present in two of the liquid products when delivered, GroutAid and Super-Parmix. The potential of the organic compounds in grout additives to be degraded by microorganisms, increasing the risk of biofilm formation and complexing compound production, must be considered. Microbial growth will also increase the possibility of hydrogen sulphide formation. (orig.)

  14. Contamination effects of drilling fluid additives on cement slurry

    Directory of Open Access Journals (Sweden)

    Youzhi Zheng

    2015-10-01

    Full Text Available During the cementation of deep wells, contamination at the contact surface between cement slurry and drilling fluid will present a technical challenge, which may threaten operation safety. To deal with the problem, lab tests and analysis were performed specifically on the compatibility of fluids during cementation in Sichuan and Chongqing gas fields. Impacts of commonly used additives for drilling fluids were determined on fluidity and thickening time of conventional cement slurry. Through the infrared spectrum analysis, SEM and XRD, infrared spectrum data of kalium polyacrylamide (KPAM and bio-viscosifier were obtained, together with infrared spectrum, SEM and XRD data of cement slurry with additives. Contamination mechanisms of the cement slurry by conventional additives for drilling fluid were reviewed. Test results show that both KPAM and bio-viscosifier are such high-molecular materials that the long chains in these materials may easily absorb cement particles in the slurry to form mixed network structures; as a result, cement particles were prone to agglomeration and eventually lost their pumpability. Finally, assessment of and testing methods for the contamination effects of drilling fluid additives on cement slurry were further improved to form standards and codes that may help solve the said problems. This study will provide technological supports for the preparation of drilling fluids with desirable properties prior to cementation, the selection of optimal drilling fluids additives, and the development of innovative drilling fluids additives.

  15. Thermal Manifestations and Nanoindentation of Bone Cements for Orthopaedic Surgery

    Czech Academy of Sciences Publication Activity Database

    Hloch, Sergej; Monka, P.; Hvizdoš, P.; Jakubéczyová, D.; Kozak, D.; Čolič, K.; Kloc, J.; Magurová, D.

    2013-01-01

    Roč. 17, č. 1 (2013), s. 251-258. ISSN 0354-9836 Institutional support: RVO:68145535 Keywords : bone cement * exothermic behaviour * nanoindentation * porosity * osteonecrosis Subject RIV: FJ - Surgery incl. Transplants Impact factor: 0.962, year: 2013

  16. Effect of heat generation from bone cement on bone tissue in total knee arthroplasty; Jinko kansetsu okikaeji no one cement no hatsunetsu ga seitai soshiki ni oyobosu eikyo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, M.; Uchida, T. [Kobe University, Kobe (Japan); Iwatsubo, T. [Kobe University, Kobe (Japan). Faculty of Engineering; Kurosawa, M.; Hashimoto, Y. [Kobe University, Kobe (Japan). Faculty of Medicine; Fukushima, H.

    1998-01-25

    Bone cement is often applied to fix the components in a surgical operation, such as TKA (total knee arthroplasty). In this paper, we consider the effect of heat generation from bone cement on bone tissue in TKA by using numerical simulation. First, we applied an axisymmetric model of tibia to finite element method and analyzed heat generation of bone cement. To confirm the results of analysis by experiment, we measured the temperature determined by 6 points i.e., 2 points each in component-cement interface, cement and bone-cement interface. As a result, the temperature determined by analysis agrees with that determined by experiment. Next, we proposed the evaluation formula of the bone necrosis. We constructed a bone necrosis map from the simulation. From the map, we found that the bone necrosis region was about 2 mm from the bone-cement interface. In addition, the bone necrosis is severe at the base of the tibial component. 7 refs., 15 figs., 3 tabs.

  17. Influence of Nano-HA Coated Bone Collagen to Acrylic (Polymethylmethacrylate Bone Cement on Mechanical Properties and Bioactivity.

    Directory of Open Access Journals (Sweden)

    Tao Li

    Full Text Available This research investigated the mechanical properties and bioactivity of polymethylmethacrylate (PMMA bone cement after addition of the nano-hydroxyapatite(HA coated bone collagen (mineralized collagen, MC.The MC in different proportions were added to the PMMA bone cement to detect the compressive strength, compression modulus, coagulation properties and biosafety. The MC-PMMA was embedded into rabbits and co-cultured with MG 63 cells to exam bone tissue compatibility and gene expression of osteogenesis.15.0%(wt impregnated MC-PMMA significantly lowered compressive modulus while little affected compressive strength and solidification. MC-PMMA bone cement was biologically safe and indicated excellent bone tissue compatibility. The bone-cement interface crosslinking was significantly higher in MC-PMMA than control after 6 months implantation in the femur of rabbits. The genes of osteogenesis exhibited significantly higher expression level in MC-PMMA.MC-PMMA presented perfect mechanical properties, good biosafety and excellent biocompatibility with bone tissues, which has profoundly clinical values.

  18. The Use of Micro and Nano Particulate Fillers to Modify the Mechanical and Material Properties of Acrylic Bone Cement

    Science.gov (United States)

    Slane, Joshua A.

    Acrylic bone cement (polymethyl methacrylate) is widely used in total joint replacements to provide long-term fixation of implants. In essence, bone cement acts as a grout by filling in the voids left between the implant and the patient's bone, forming a mechanical interlock. While bone cement is considered the `gold standard' for implant fixation, issues such as mechanical failure of the cement mantle (aseptic loosening) and the development of prosthetic joint infection (PJI) still plague joint replacement procedures and often necessitate revision arthroplasty. In an effort to address these failures, various modifications are commonly made to bone cement such as mechanical reinforcement with particles/fibers and the addition of antibiotics to mitigate PJI. Despite these attempts, issues such as poor particle interfacial adhesion, inadequate drug release, and the development of multidrug resistant bacteria limit the effectiveness of bone cement modifications. Therefore, the overall goal of this work was to use micro and nanoparticles to enhance the properties of acrylic bone cement, with particular emphasis placed on improving the mechanical properties, cumulative antibiotic release, and antimicrobial properties. An acrylic bone cement (Palacos R) was modified with three types of particles in various loading ratios: mesoporous silica nanoparticles (for mechanical reinforcement), xylitol microparticles (for increased antibiotic release), and silver nanoparticles (as an antimicrobial agent). These particles were used as sole modifications, not in tandem with one another. The resulting cement composites were characterized using a variety of mechanical (macro to nano, fatigue, fracture, and dynamic), imaging, chemical, thermal, biological, and antimicrobial testing techniques. The primary outcomes of this dissertation demonstrate that: (1) mesoporous silica, as used in this work, is a poor reinforcement phase for acrylic bone cement, (2) xylitol can significantly

  19. Bone-Cement: The new medical quick fix

    Directory of Open Access Journals (Sweden)

    Dinesh Bhatia

    2010-01-01

    Full Text Available Bone Cement is being widely used in vertebroplasty, a minimally invasive surgical procedure to treat spinal frac-tures and collapsed vertebrae. It is being labeled as a concrete success in medical field. It is being used to treat fractures due to osteoporosis, menopause, steroids, hyperthyroidism and chronic obstructive pulmonary diseases. In this technique a needle with bone cement (PMMA, polymethylmethacrylate is injected into the collapsed verte-bra after administering local anesthesia to patient. It solidifies within few minutes and provides support to damaged bone resulting in relief to the patient. It also prevents the movement between different parts of the broken bone. Hence it requires a short hospital stay for the patient and the procedure can be performed with much ease and at significant lower costs. Patient can resume normal activity within a day or so. Bone cement is now being referred to as the quick medical fix material for early repair of fractures.

  20. Experimental study with domestic bone cement in the percutaneous vertebroplasty

    International Nuclear Information System (INIS)

    Objective: To study the feasibility of injecting domestic bone cement in the process of the percutaneous vertebroplasty. Methods: (1) Various types cement were disposed with domestic PMMA. The concretionary phases of cement were observed according to the stages and holding time. Then the most ideal ratio of the mixed cement was selected and ten cement columns were made with this ratio, which was taken as the trial group. The other ten referring to was taken as the contrast one. The biological mechanics was measured with a load and the data of the results were compared. (2) Twenty thoracic and lumbar adjacent bodies were removed intact from five human corpses. These bodies were divided into two groups, in one group PMMA were injected, the other was severed as the contrast one. Then in these twenty vertebral bodies the biological mechanics was measured and the treatment effect was evaluated. (3) In 12 healthy dogs PVP in lumber was tried so as to observe the operational difficulty during the process of injected this bone cement and CT was used to evaluate the result of PMMA, diffusion and the complications caused by it. Results: The most ideal ratio was 4:2.6:1 (g, ml, ml) between powder, monome and contrast. After injecting this kind of cement, the loading strength of these vertebral bodies was increased remarkably (P<0.01). Conclusion: Injecting domestic bone cement provides the theoretical foundations for the clinical application of PVP. (author)

  1. Experimental in-vitro bone cements disintegration with ultrasonic pulsating water jet for revision arthroplasty

    OpenAIRE

    S. Hloch; Foldyna, J.; Pude, F.; Kloc, J.; M. Zeleňák; Hvizdoš, P.; Monka, P.; Smolko, I.; Ščučka, J. (Jiří); Kozak, D.; A. Sedmak; Mihalčinová, E.

    2015-01-01

    The paper deals with the study of using the selective property of ultrasonic pulsating water jet for the disintegration of the interface created by bone cement between cemented femoral stem and trabecular bone tissue as a potential technique for revision arthroplasty. Six types of commercial bone cements based on Polymethyl Methacrylate were used for investigation. The cements were mixed using the DePuy - SmartMix® CTS / vacuum mixing bowl. Mechanical properties of hardened bone cements were ...

  2. Bioactive PMMA bone cement prepared by modification with methacryloxypropyltrimethoxysilane and calcium chloride.

    Science.gov (United States)

    Miyazaki, Toshiki; Ohtsuki, Chikara; Kyomoto, Masayuki; Tanihara, Masao; Mori, Akiko; Kuramoto, Kou-ichi

    2003-12-15

    Bone cement consisting of polymethylmethacrylate (PMMA) powder and methylmethacrylate (MMA) liquid is used extensively for fixation of implants such as artificial hip joints with living bone. This type of cement, however, does not show direct bonding to the living body, and hence the fixation is liable to loosen over a long implantation period. Bioactive materials have received much attention because of their capability for bone-bonding, i.e., bioactivity, when implanted in bony defects. Osteoconduction of the bioactive materials is caused by formation of a bone-like apatite layer through a surface reaction between the material and surrounding body fluid. The apatite formation can be induced by a silanol (Sibond;OH) group formed on the materials as well as a dissolution of calcium ion (Ca(2+)) from the material. Incorporation of alkoxysilane and calcium chloride (CaCl(2)) may provide PMMA bone cement with bioactivity, because alkoxysilane gives Sibond;OH after hydrolysis, whereas CaCl(2) releases Ca(2+). In this study, we investigated the potential on bioactivity of the modified PMMA bone cement with alkoxysilane and calcium chloride. PMMA powder was mixed with various amounts of CaCl(2), and MMA liquid with various amounts of 3-methacryloxypropyltrimethoxysilane (MPS). The mixed paste was immersed in a simulated body fluid (Kokubo solution) that has a similar concentration in inorganic constituents to human blood plasma. After soaking for various periods, apatite formation on the cement was examined. Apatite formation was observed by the addition of CaCl(2) with contents of 16 mass % and more. Incorporation of MPS accelerates the apatite formation. Setting time of the cement was significantly elongated after the addition of MPS, whereas compressive strength significantly decreased with increasing the contents of CaCl(2) and MPS. The hardened cement containing 20 mass % of CaCl(2) in the powder and 20 mass % of MPS in the liquid showed a tendency to be more

  3. Cement line staining in undecalcified thin sections of cortical bone

    Science.gov (United States)

    Bain, S. D.; Impeduglia, T. M.; Rubin, C. T.

    1990-01-01

    A technique for demonstrating cement lines in thin, undecalcified, transverse sections of cortical bone has been developed. Cortical bone samples are processed and embedded undecalcified in methyl methacrylate plastic. After sectioning at 3-5 microns, cross-sections are transferred to a glass slide and flattened for 10 min. Sections of cortical bone are stained for 20 sec free-floating in a fresh solution of 1% toluidine blue dissolved in 0.1% formic acid. The section is dehydrated in t-butyl alcohol, cleared in xylene, and mounted with Eukitt's medium. Reversal lines appear as thin, scalloped, dark blue lines against a light blue matrix, whereas bone formation arrest lines are thicker with a smooth contour. With this technique cellular detail, osteoid differentiation, and fluorochrome labels are retained. Results demonstrate the applicability of a one-step staining method for cement lines which will facilitate the assessment of bone remodeling activity in thin sections of undecalcified cortical bone.

  4. Osteoplasty: Percutaneous Bone Cement Injection beyond the Spine

    OpenAIRE

    Anselmetti, Giovanni Carlo

    2010-01-01

    Percutaneous osteoplasty, the injection of bone cement into a painful bone lesion refractory to conventional therapy (radiotherapy, chemotherapy, and narcotic analgesia), is performed to allow for immediate bone structure consolidation, reduce the risk of a pathological fracture, achieve pain regression, and improve mobility. In this article, the technique of this procedure and a review of the current literature including the author's personal large series will be described.

  5. Biological Evaluation of α-TCP/TTCP Composite Bone Cement

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    α-tricalcium phosphate(α-TCP)/tetracalcium phosphate(TTCP) composite bone cement had good hydration characteristic.In our system,α-TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g*mL-1.The setting time could be adjusted,the maximum compressive strength was 45.36MPa,and the hydration product was hydroxyapatite (HAP).In vitro biological simulated experiments indicate that α-TCP/TTCP bone cement has α certain dissolubility.The hardened product is mainly HAP after soaking in simulated body fluid (SBF) for 10 weeks.The results of in vitro test and animal experiments and SEM analyses show that no local or general toxicity response,no muscle stimulation,no haemolysis,no cruor,no inflammatory reaction and no exclusion response are caused by α-TCP/TTCP cement, which can be contributed to bone tissue spreading and impinging.α-TCP/TTCP cement hydrated and hardened continually in vivo.The materials fused with host bone together with implanting time prolonging.Therefore,it is believed that α-TCP/TTCP composite bone cement has a high biocompatibility and bioactivity,a certain biodegradation and good osteogenesis as well.

  6. (α'(H))-Dicalcium silicate bone cement doped with tricalcium phosphate: characterization, bioactivity and biocompatibility.

    Science.gov (United States)

    de Aza, Piedad N; Zuleta, Fausto; Velasquez, Pablo; Vicente-Salar, Nestor; Reig, Juan A

    2014-02-01

    The influence of phosphorus doping on the properties of (α'(H))-dicalcium silicate (C(2)S) bone cement was analyzed, in addition to bioactivity and biocompatibility. All the cements were composed of a solid solution of TCP in C(2)S ([Formula: see text]-C(2)S(ss)) as the only phase present. The compressive strength ranged from 3.8-16.3 MPa. Final setting times ranged from 10 to 50 min and were lower for cements with lower L/P content. Calcium silicate hydrate was the principal phase formed during the hydration process of the cements. The cement exhibited a moderate degradation and could induce carbonated hydroxyapatite formation on its surface and into the pores. The cell attachment test showed that the (α'(H))-C(2)SiO(4) solid solution supported human adipose stem cells adhesion and spreading, and the cells established close contacts with the cement after 24 h of culture. The novel (α'(H))-C(2)S(ss) cements might be suitable for potential applications in the biomedical field, preferentially as materials for bone/dental repair. PMID:24218299

  7. Preparation and in vitro evaluation of strontium-doped calcium silicate/gypsum bioactive bone cement

    International Nuclear Information System (INIS)

    The combination of two or more bioactive components with different biodegradability could cooperatively improve the physicochemical and biological performances of the biomaterials. Here we explore the use of α-calcium sulfate hemihydrate (α-CSH) and calcium silicate with and without strontium doping (Sr-CSi, CSi) to fabricate new bioactive cements with appropriate biodegradability as bone implants. The cements were fabricated by adding different amounts (0–35 wt%) of Sr-CSi (or CSi) into the α-CSH-based pastes at a liquid-to-solid ratio of 0.4. The addition of Sr-CSi into α-CSH cements not only led to a pH rise in the immersion medium, but also changed the surface reactivity of cements, making them more bioactive and therefore promoting apatite mineralization in simulated body fluid (SBF). The impact of additives on long-term in vitro degradation was evaluated by soaking the cements in Tris buffer, SBF, and α-minimal essential medium (α-MEM) for a period of five weeks. An addition of 20% Sr-CSi to α-CSH cement retarded the weight loss of the samples to 36% (in Tris buffer), 43% (in SBF) and 54% (in α-MEM) as compared with the pure α-CSH cement. However, the addition of CSi resulted in a slightly faster degradation in comparison with Sr-CSi in these media. Finally, the in vitro cell-ion dissolution products interaction study using human fetal osteoblast cells demonstrated that the addition of Sr-CSi improved cell viability and proliferation. These results indicate that tailorable bioactivity and biodegradation behavior can be achieved in gypsum cement by adding Sr-CSi, and such biocements will be of benefit for enhancing bone defect repair. (paper)

  8. Prediction of the Setting Properties of Calcium Phosphate Bone Cement

    Directory of Open Access Journals (Sweden)

    Seyed Mahmud Rabiee

    2012-01-01

    Full Text Available Setting properties of bone substitutes are improved using an injectable system. The injectable bone graft substitutes can be molded to the shape of the bone cavity and set in situ when injected. Such system is useful for surgical operation. The powder part of the injectable bone cement is included of β-tricalcium phosphate, calcium carbonate, and dicalcium phosphate and the liquid part contains poly ethylene glycol solution with different concentrations. In this way, prediction of the mechanical properties, setting times, and injectability helps to optimize the calcium phosphate bone cement properties. The objective of this study is development of three different adaptive neurofuzzy inference systems (ANFISs for estimation of compression strength, setting time, and injectability using the data generated based on experimental observations. The input parameters of models are polyethylene glycol percent and liquid/powder ratio. Comparison of the predicted values and measured data indicates that the ANFIS model has an acceptable performance to the estimation of calcium phosphate bone cement properties.

  9. Prediction of the setting properties of calcium phosphate bone cement.

    Science.gov (United States)

    Rabiee, Seyed Mahmud; Baseri, Hamid

    2012-01-01

    Setting properties of bone substitutes are improved using an injectable system. The injectable bone graft substitutes can be molded to the shape of the bone cavity and set in situ when injected. Such system is useful for surgical operation. The powder part of the injectable bone cement is included of β-tricalcium phosphate, calcium carbonate, and dicalcium phosphate and the liquid part contains poly ethylene glycol solution with different concentrations. In this way, prediction of the mechanical properties, setting times, and injectability helps to optimize the calcium phosphate bone cement properties. The objective of this study is development of three different adaptive neurofuzzy inference systems (ANFISs) for estimation of compression strength, setting time, and injectability using the data generated based on experimental observations. The input parameters of models are polyethylene glycol percent and liquid/powder ratio. Comparison of the predicted values and measured data indicates that the ANFIS model has an acceptable performance to the estimation of calcium phosphate bone cement properties. PMID:22919372

  10. Wear and Mechanical Behaviour of Various Polymethylmethacrylate Bone Cements

    Czech Academy of Sciences Publication Activity Database

    Balko, J.; Ballóková, B.; Jakubéczyová, D.; Hvizdoš, P.; Hloch, Sergej; Kloc, J.; Monka, P.

    2013-01-01

    Roč. 13, č. 1 (2013), s. 34-43. ISSN 1335-8987 Institutional support: RVO:68145535 Keywords : bone cements * mixing * pin-on-plate * porosity * nano-hardness Subject RIV: JQ - Machines ; Tools http://www.imr.saske.sk/pmp/issue/1-2013/PMP_Vol13_No1_p_034-043.pdf

  11. In Vitro and In Vivo Response to Low-Modulus PMMA-Based Bone Cement

    Directory of Open Access Journals (Sweden)

    Elin Carlsson

    2015-01-01

    Full Text Available The high stiffness of acrylic bone cements has been hypothesized to contribute to the increased number of fractures encountered after vertebroplasty, which has led to the development of low-modulus cements. However, there is no data available on the in vivo biocompatibility of any low-modulus cement. In this study, the in vitro cytotoxicity and in vivo biocompatibility of two types of low-modulus acrylic cements, one modified with castor oil and one with linoleic acid, were evaluated using human osteoblast-like cells and a rodent model, respectively. While the in vitro cytotoxicity appeared somewhat affected by the castor oil and linoleic acid additions, no difference could be found in the in vivo response to these cements in comparison to the base, commercially available cement, in terms of histology and flow cytometry analysis of the presence of immune cells. Furthermore, the in vivo radiopacity of the cements appeared unaltered. While these results are promising, the mechanical behavior of these cements in vivo remains to be investigated.

  12. Anterior spinal column augmentation with injectable bone cements.

    Science.gov (United States)

    Verlaan, Jorrit-Jan; Oner, F Cumhur; Dhert, Wouter J A

    2006-01-01

    A vertebral fracture, whether originating from osteoporosis or trauma, can be the cause of pain, disability, deformation and neurological deficit. The treatment of vertebral compression fractures has, for many years until the advent of vertebroplasty, consisted of bedrest and analgesics. Vertebroplasty is a percutaneous technique during which bone cement is injected in a vertebral body to provide immediate pain relief by stabilization. Inflatable bone tamps can, prior to the injection of cement, be used to create a void in the vertebral body, in which case the technique is known as balloon vertebroplasty (or kyphoplasty). The chance of extracorporal cement leakage is smaller for balloon vertebroplasty than for vertebroplasty. Some authors also claim to have gained some correction in vertebral body height or angulation. Both interventions can be used for several indications, including osteoporotic compression fractures and osteolytic lesions of the vertebral body such as myeloma, hemangioma or metastasis, and also for traumatic burst fractures in combination with pedicle screw instrumentation. Polymethyl methacrylate cement is the bone void filler that is used most frequently, although the application of calcium phosphate cements has been studied widely in vitro, in vivo and also in small-scale clinical series. The clinical results of (balloon-) vertebroplasty are favorable with 85-95% of all patients experiencing immediate and long-lasting relief of pain. Serious complications are relatively rare but include neurological deficit and pulmonary embolism. In this paper, both vertebroplasty and balloon vertebroplasty and their respective indications, techniques and results are described in relation with the application and limitations of permanent and resorbable injectable bone cements. PMID:16102818

  13. Development of a biodegradable bone cement for craniofacial applications.

    Science.gov (United States)

    Henslee, Allan M; Gwak, Dong-Ho; Mikos, Antonios G; Kasper, F Kurtis

    2012-09-01

    This study investigated the formulation of a two-component biodegradable bone cement comprising the unsaturated linear polyester macromer poly(propylene fumarate) (PPF) and crosslinked PPF microparticles for use in craniofacial bone repair applications. A full factorial design was employed to evaluate the effects of formulation parameters such as particle weight percentage, particle size, and accelerator concentration on the setting and mechanical properties of crosslinked composites. It was found that the addition of crosslinked microparticles to PPF macromer significantly reduced the temperature rise upon crosslinking from 100.3°C ± 21.6°C to 102.7°C ± 49.3°C for formulations without microparticles to 28.0°C ± 2.0°C to 65.3°C ± 17.5°C for formulations with microparticles. The main effects of increasing the particle weight percentage from 25 to 50% were to significantly increase the compressive modulus by 37.7 ± 16.3 MPa, increase the compressive strength by 2.2 ± 0.5 MPa, decrease the maximum temperature by 9.5°C ± 3.7°C, and increase the setting time by 0.7 ± 0.3 min. Additionally, the main effects of increasing the particle size range from 0-150 μm to 150-300 μm were to significantly increase the compressive modulus by 31.2 ± 16.3 MPa and the compressive strength by 1.3 ± 0.5 MPa. However, the particle size range did not have a significant effect on the maximum temperature and setting time. Overall, the composites tested in this study were found to have properties suitable for further consideration in craniofacial bone repair applications. PMID:22499285

  14. Evaluation of brazilian bentonites as additive in the radwaste cementation

    International Nuclear Information System (INIS)

    The behavior of some Brazilian bentonites has been evaluated, concerning to their use as additive in the radwaste cementation. The purpose of the bentonite is to retain the radioelements in the final product in leaching process. Experiments to determine properties such as compressive strenght, viscosity, set time leaching and cesium sorption have been carried out to this evaluation. After one-year test, the results show that the bentonites greatly reduce the cesium release. A literature survey about cementation process and plants and about the cement product characteristics has been made in order to obtain a reliable final product, able to be transported and storaged. Some leaching test methods and mathematical models, that could be applied in the evaluation of cement products with bentonite have been evaluated. (author)

  15. A Study of Metal-Cement Composites with Additives

    Directory of Open Access Journals (Sweden)

    Mironov Victor

    2014-12-01

    Full Text Available The application of small-sized metal fillers (SMF provides a combination of high bulk density, increased durability and ferromagnetic properties of composite materials on the cement basis. However, the total strength of the composite can be compromised by poor adhesion of metal particles with the cement matrix. The use of versatile additives like microsilica and metakaolin is able to improve the structural integrity and mechanical properties of heavy concretes. The paper considers the results of a study using specimens of heavy concretes with SMF aiming to estimate its strength, structural features and ultrasonic parameters. It was found that the contact of SMF particles with the cement was not perfect, since the voids appeared between them and the cement matrix during the cement hydration process (exothermal reaction. Due to the border porosity, the specimens with the metal fillers have lower compressive strength, lower ultrasound velocity and increased frequency slope of attenuation. Microsilica and metakaolin additives facilitate better contact zone between the cement matrix and metal fillers.

  16. Silver-Doped Calcium Phosphate Bone Cements with Antibacterial Properties

    Science.gov (United States)

    Rau, J. V.; Fosca, M.; Graziani, V.; Egorov, A. A.; Zobkov, Yu. V.; Fedotov, A. Yu.; Ortenzi, M.; Caminiti, R.; Baranchikov, A. E.; Komlev, V. S.

    2016-01-01

    Calcium phosphate bone cements (CPCs) with antibacterial properties are demanded for clinical applications. In this study, we demonstrated the use of a relatively simple processing route based on preparation of silver-doped CPCs (CPCs-Ag) through the preparation of solid dispersed active powder phase. Real-time monitoring of structural transformations and kinetics of several CPCs-Ag formulations (Ag = 0 wt %, 0.6 wt % and 1.0 wt %) was performed by the Energy Dispersive X-ray Diffraction technique. The partial conversion of β-tricalcium phosphate (TCP) phase into the dicalcium phosphate dihydrate (DCPD) took place in all the investigated cement systems. In the pristine cement powders, Ag in its metallic form was found, whereas for CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, CaAg(PO3)3 was detected and Ag (met.) was no longer present. The CPC-Ag 0 wt % cement exhibited a compressive strength of 6.5 ± 1.0 MPa, whereas for the doped cements (CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt %) the reduced values of the compressive strength 4.0 ± 1.0 and 1.5 ± 1.0 MPa, respectively, were detected. Silver-ion release from CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, measured by the Atomic Emission Spectroscopy, corresponds to the average values of 25 µg/L and 43 µg/L, respectively, rising a plateau after 15 days. The results of the antibacterial test proved the inhibitory effect towards pathogenic Escherichia coli for both CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, better performances being observed for the cement with a higher Ag-content. PMID:27096874

  17. Bone-Cement: The New Medical Quick Fix

    Directory of Open Access Journals (Sweden)

    Dinesh Bhatia

    2010-01-01

    Full Text Available

    Bone Cement is being widely used in vertebroplasty, a minimally invasive surgical procedure to treat spinal fractures and collapsed vertebrae. It is being labeled as a concrete success in medical field. It is being used to treat fractures due to osteoporosis, menopause, steroids, hyperthyroidism and chronic obstructive pulmonary diseases.  In this technique a needle with bone cement (PMMA, polymethylmethacrylate is injected into the collapsed vertebra after administering local anesthesia to patient. It solidifies within few minutes and provides support to damaged bone resulting in relief to the patient. It also prevents the movement between different parts of the broken bone. Hence it requires a short hospital stay for the patient and the procedure can be performed with much ease and at significant lower costs. Patient can resume normal activity within a day or so. Bone cement is now being referred to as the quick medical fix material for early repair of fractures.

  18. Early hydration of portland cement with crystalline mineral additions

    International Nuclear Information System (INIS)

    This research presents the effects of finely divided crystalline mineral additions (quartz and limestone), commonly known as filler, on the early hydration of portland cements with very different mineralogical composition. The used techniques to study the early hydration of blended cements were conduction calorimeter, hydraulicity (Fratini's test), non-evaporable water and X-ray diffraction. Results showed that the stimulation and the dilution effects increase when the percentage of crystalline mineral additions used is increased. Depending on the replacement proportion, the mineralogical cement composition and the type of crystalline addition, at 2 days, the prevalence of the dilution effect or the stimulation effect shows that crystalline mineral additions could act as sites of heat dissipation or heat stimulation, respectively

  19. The effect of the antimicrobial peptide, Dhvar-5, on gentamicin release from a polymethyl methacrylate bone cement.

    Science.gov (United States)

    Faber, C; Hoogendoorn, R J W; Lyaruu, D M; Stallmann, H P; van Marle, J; van Nieuw Amerongen, A; Smit, T H; Wuisman, P I J M

    2005-10-01

    The objective of this study was to investigate the release mechanism and kinetics of the antimicrobial peptide, Dhvar-5, both alone and in combination with gentamicin, from a standard commercial polymethyl methacrylate (PMMA) bone cement. Different amounts of Dhvar-5 were mixed with the bone cement powders of Osteopal and the gentamicin-containing Osteopal G bone cement and their release kinetics from the polymerized cement were investigated. Additionally, the internal structure of the bone cements were analysed by scanning electron microscopy (SEM) of the fracture surfaces. Secondly, porosity was investigated with the mercury intrusion method and related to the observed release profiles. In order to obtain an insight into the mechanical characteristics of the bone cement mixtures, the compressive strength of Osteopal and Osteopal G with Dhvar-5 was also investigated. The total Dhvar-5 release reached 96% in the 100 mg Dhvar-5/g Osteopal cement, whereas total gentamicin release from Osteopal G reached only 18%. Total gentamicin release increased significantly to 67% with the addition of 50mg Dhvar-5/g, but the Dhvar-5 release was not influenced. SEM showed an increase of dissolved gentamicin crystals with the addition of Dhvar-5. The mercury intrusion results suggested an increase of small pores (cements. We therefore conclude that the antimicrobial peptide, Dhvar-5, was released in high amounts from PMMA bone cement. When used together with gentamicin sulphate, Dhvar-5 made the gentamicin crystals accessible for the release medium presumably through increased micro-porosity (< 0.1 microm) resulting in a fourfold increase of gentamicin release. PMID:15878377

  20. Magnesium substitution in brushite cements for enhanced bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Cabrejos-Azama, Jatsue, E-mail: jacaza@farm.ucm.es [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain); Departamento de Estomatología III, Facultad de Odontología UCM, Madrid (Spain); Alkhraisat, Mohammad Hamdan; Rueda, Carmen [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain); Torres, Jesús [Facultad de Ciencias de la salud URJC, Alcorcón, Madrid (Spain); Blanco, Luis [Departamento de Estomatología III, Facultad de Odontología UCM, Madrid (Spain); López-Cabarcos, Enrique [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain)

    2014-10-01

    We have synthesized calcium phosphate cements doped with different amounts of magnesium (Mg-CPC) with a twofold purpose: i) to evaluate in vitro the osteoblast cell response to this material, and ii) to compare the bone regeneration capacity of the doped material with a calcium cement prepared without magnesium (CPC). Cell proliferation and in vivo response increased in the Mg-CPCs in comparison with CPC. The Mg-CPCs have promoted higher new bone formation than the CPC (p < 0.05). The cytocompatibility and histomorfometric analysis performed in the rabbit calvaria showed that the incorporation of magnesium ions in CPC improves osteoblasts proliferation and provides higher new bone formation. The development of a bone substitute with controllable biodegradable properties and improved bone regeneration can be considered a step toward personalized therapy that can adapt to patient needs and clinical situations. - Highlights: • The Mg-CPCs promote higher new bone formation than the CPC. • The incorporation of magnesium ions in CPC improves osteoblasts proliferation. • Mg-CPC is a bone substitute with controllable biodegradable properties. • We suggest that the use of Mg ions could improve the clinical efficiency of CPCs.

  1. Magnesium substitution in brushite cements for enhanced bone tissue regeneration

    International Nuclear Information System (INIS)

    We have synthesized calcium phosphate cements doped with different amounts of magnesium (Mg-CPC) with a twofold purpose: i) to evaluate in vitro the osteoblast cell response to this material, and ii) to compare the bone regeneration capacity of the doped material with a calcium cement prepared without magnesium (CPC). Cell proliferation and in vivo response increased in the Mg-CPCs in comparison with CPC. The Mg-CPCs have promoted higher new bone formation than the CPC (p < 0.05). The cytocompatibility and histomorfometric analysis performed in the rabbit calvaria showed that the incorporation of magnesium ions in CPC improves osteoblasts proliferation and provides higher new bone formation. The development of a bone substitute with controllable biodegradable properties and improved bone regeneration can be considered a step toward personalized therapy that can adapt to patient needs and clinical situations. - Highlights: • The Mg-CPCs promote higher new bone formation than the CPC. • The incorporation of magnesium ions in CPC improves osteoblasts proliferation. • Mg-CPC is a bone substitute with controllable biodegradable properties. • We suggest that the use of Mg ions could improve the clinical efficiency of CPCs

  2. Benefits and drawbacks of zinc in glass ionomer bone cements

    International Nuclear Information System (INIS)

    Glass polyalkenoate (ionomer) cements (GPCs) based on poly(acrylic acid) and fluoro-alumino-silicate glasses are successfully used in a variety of orthopaedic and dental applications; however, they release small amounts of aluminium, which is a neurotoxin and inhibits bone mineralization in vivo. Therefore there has been significant interest in developing aluminium-free glasses containing zinc for forming GPCs because zinc can play a similar structural role in the glass, allowing for glass degradation and subsequent cement setting, and is reported to have beneficial effects on bone formation. We created zinc-containing GPCs and characterized their mechanical properties and biocompatibility. Zinc-containing cements showed adhesion to bone close to 1 MPa, which was significantly greater than that of zinc-free cements (2+ or more resulted in cell death. In summary, we demonstrate that while zinc-containing GPCs possess excellent mechanical properties, they fail basic biocompatibility tests, produce an acute cytotoxic response in vitro, which may preclude their use in vivo.

  3. Osteoconductivity and mechanical properties of a new bioactive bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Shinzato, S.; Nakamura, T. [Kyoto Univ. (Japan). Dept. of Orthopaedic Surgery; Kokubo, T. [Kyoto Univ. (Japan). Dept. of Material Chemistry; Kitamura, Y. (Nippon Electric Glass Co. Ltd., Otsu)

    2001-07-01

    Osteoconductivity and mechanical properties of a new bioactive bone cement (designated GBC) consisting of high molecular weight polymethyl methacrylate (PMMA) as an organic matrix and bioactive glass beads as an inorganic filler have been evaluated. The bioactive beads consisting of MgO-CaO-SiO{sub 2}-P{sub 2}O{sub 5}CaF{sub 2} glass, have been newly designed and a novel PMMA powder was selected. The aim of the present study is to compare GBC's osteoconductivity and mechanical properties with cements consisting of the same matrix as GBC and either apatite- and wollastonite-containing glass-ceramic (AW-GC) powder (designated AWC) or sintered hydroxyapatite (HA) powder (designated HAC) and to examine effects of the amount of the bioactive glass beads filler added to GBC, and to decide the most suitable amount of the filler content. The bioactive glass beads added to the cements amounted 30, 40, 50, 60, and 70 wt%, and AW-GC powder and HA powder added to the cements amounted 70 wt%. Each cement was designated respectively GBC30, 40, 50, 60, 70, AWC70, and HAC70. The bending strength of GBC70 was significantly higher than that of AWC70 and HAC70. The compressive strength and the elastic modulus of bending of GBC increased as the glass beads content increased. The handling property of each GBC was comparable with that of conventional PMMA bone cement. Cements were packed into intramedullar canals of rat tibiae in order to evaluate osteoconductivity determined by an affinity index.

  4. On the development of an apatitic calcium phosphate bone cement

    Indian Academy of Sciences (India)

    Manoj Komath; H K Varma; R Sivakumar

    2000-04-01

    Development of an apatitic calcium phosphate bone cement is reported. 100 Particles of tetracalcium phosphate (TTCP) and dicalcium phosphate dihydrate (DCPD) were mixed in equimolar ratio to form the cement powder. The wetting medium used was distilled water with Na2HPO4 as accelerator to manipulate the setting time. The cement powder, on wetting with the medium, formed a workable putty. The setting times of the putty were measured using a Vicat type apparatus and the compressive strength was determined with a Universal Testing Machine. The nature of the precipitated cement was analyzed through X-ray diffraction (XRD), fourier transform infrared spectrometry (FTIR) and energy dispersive electron microprobe (EDAX). The results showed the phase to be apatitic with a calcium–to–phosphorous ratio close to that of hydroxyapatite. The microstructure analysis using scanning electron microscopy (SEM) showed hydroxyapatite nanocrystallite growth over particulate matrix surface. The structure has an apparent porosity of ∼ 52%. There were no appreciable dimensional or thermal changes during setting. The cement passed the in vitro toxicological screening (cytotoxicity and haemolysis) tests. Optimization of the cement was done by manipulating the accelerator concentration so that the setting time, hardening time and the compressive strength had clinically relevant values.

  5. Hydration of Portland cement with additions of calcium sulfoaluminates

    Energy Technology Data Exchange (ETDEWEB)

    Le Saout, Gwenn, E-mail: gwenn.le-saout@mines-ales.fr [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Lothenbach, Barbara [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Hori, Akihiro [DENKA Chemicals GmbH, Wehrhahn-Center, Cantadorstr. 3, D-40211 Duesseldorf (Germany); Higuchi, Takayuki [Denki Kagaku Kogyo Kabushiki Kaisha (DENKA), Omi, Itoigawa, Niigata, 949-0393 (Japan); Winnefeld, Frank [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)

    2013-01-15

    The effect of mineral additions based on calcium aluminates on the hydration mechanism of ordinary Portland cement (OPC) was investigated using isothermal calorimetry, thermal analysis, X-ray diffraction, scanning electron microscopy, solid state nuclear magnetic resonance and pore solution analysis. Results show that the addition of a calcium sulfoaluminate cement (CSA) to the OPC does not affect the hydration mechanism of alite but controls the aluminate dissolution. In the second blend investigated, a rapid setting cement, the amorphous calcium aluminate reacts very fast to ettringite. The release of aluminum ions strongly retards the hydration of alite but the C-S-H has a similar composition as in OPC with no additional Al to Si substitution. As in CSA-OPC, the aluminate hydration is controlled by the availability of sulfates. The coupling of thermodynamic modeling with the kinetic equations predicts the amount of hydrates and pore solution compositions as a function of time and validates the model in these systems.

  6. Hydration of Portland cement with additions of calcium sulfoaluminates

    International Nuclear Information System (INIS)

    The effect of mineral additions based on calcium aluminates on the hydration mechanism of ordinary Portland cement (OPC) was investigated using isothermal calorimetry, thermal analysis, X-ray diffraction, scanning electron microscopy, solid state nuclear magnetic resonance and pore solution analysis. Results show that the addition of a calcium sulfoaluminate cement (CSA) to the OPC does not affect the hydration mechanism of alite but controls the aluminate dissolution. In the second blend investigated, a rapid setting cement, the amorphous calcium aluminate reacts very fast to ettringite. The release of aluminum ions strongly retards the hydration of alite but the C–S–H has a similar composition as in OPC with no additional Al to Si substitution. As in CSA–OPC, the aluminate hydration is controlled by the availability of sulfates. The coupling of thermodynamic modeling with the kinetic equations predicts the amount of hydrates and pore solution compositions as a function of time and validates the model in these systems.

  7. Modelling and simulation of acrylic bone cement injection and curing within the framework of vertebroplasty

    CERN Document Server

    Landgraf, Ralf; Kolmeder, Sebastian; Lion, Alexander; Lebsack, Helena; Kober, Cornelia

    2013-01-01

    The minimal invasive procedure of vertebroplasty is a surgical technique to treat compression fractures of vertebral bodies. During the treatment liquid bone cement gets injected into the affected vertebral body and therein cures to a solid. In order to investigate the treatment and the impact of injected bone cement on the vertebra, an integrated modelling and simulation framework has been developed. The framework includes (i) the generation of computer models based on microCT images of human cancellous bone, (ii) CFD simulations of bone cement injection into the trabecular structure of a vertebral body as well as (iii) non-linear FEM simulations of the bone cement curing. Thereby, microstructural models of trabecular bone structures are employed. Furthermore, a detailed description of the material behaviour of acrylic bone cements is provided. More precisely, a non-linear fluid flow model is chosen for the representation of the bone cement behaviour during injection and a non-linear viscoelastic material mo...

  8. Utilization of gold tailings as an additive in Portland cement.

    Science.gov (United States)

    Celik, Ozlem; Elbeyli, Iffet Yakar; Piskin, Sabriye

    2006-06-01

    Mine tailings are formed as an industrial waste during coal and ore mining and processing. In the investigated process, following the extraction of gold from the ore, the remaining tailings are subjected to a two-stage chemical treatment in order to destroy the free cyanide and to stabilize and coagulate heavy metals prior to discharge into the tailings pond. The aim of this study was the investigation of the feasibility of utilization of the tailings as an additive material in Portland cement production. For this purpose, the effects of the tailings on the compressive strength properties of the ordinary Portland cement were investigated. Chemical and physical properties, mineralogical composition, particle size distribution and microstructure of the tailings were determined by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), particle size analyzer (Mastersizer) and scanning electron microscope (SEM). Following the characterization of the tailings, cement mortars were prepared by intergrinding Portland cement with dried tailings. Composition of the cement clinkers were adjusted to contain 5, 15, 25% (wt/wt) dried tailings and also silica fume and fly ash samples (C and F type) were added to clinker in different ratios. The mortars produced with different amounts of tailings, silica fume, fly ashes and also mixtures of them were tested for compressive strength values after 2, 7, 28 and 56 days according to the European Standard (EN 196-1). The results indicated that gold tailings up to 25% in clinker could be beneficially used as an additive in Portland cement production. It is suggested that the gold tailings used in the cement are blended with silica fume and C-type fly ash to obtain higher compressive strength values. PMID:16784164

  9. Bone cement with a modified polyphosphate network structure stimulates hard tissue regeneration.

    Science.gov (United States)

    Lee, Byung-Hyun; Hong, Min-Ho; Kim, Min-Chul; Kwon, Jae-Sung; Ko, Yeong-Mu; Choi, Heon-Jin; Lee, Yong-Keun

    2016-09-01

    In this study, a calcium polyphosphate cement (CpPC) consisting of basic components was investigated to assess its potential for hard tissue regeneration. The added basic components for improving the structural stability, which controlled the setting time, where the setting reaction resulted in the formation of amorphous structure with a re-constructed polyphosphate. Moreover, the characteristics were controlled by the composition, which determined the polyphosphate structure. CpPC exhibited outstanding dissolution rate compared with the common biodegradable cement, brushite cement (2.5 times). Despite high amounts of dissolution products, no significant cytotoxicity ensued. Induction of calcification in MG-63 cells treated with CpPC, the level of calcification increased with increasing CpPC dissolution rate. Induced calcification was observed also in CpPC-treated ST2 cells, in contrast with MG-63 and ST2 treated with brushite cement, for which no calcification was observed. In vivo tests using a rat calvarial defect model showed that resorbed CpPC resulted in favorable host responses and promoted bone formation. Additionally, there was a significant increase in defect closure, and new bone formation progressed from CpPC mid-sites as well as defect margins. From these results, CpPC exhibits significant potential as biodegradable bone substitute for bone regeneration. PMID:27511981

  10. Use of red mud as addition for portland cement mortars

    International Nuclear Information System (INIS)

    The aim of the present research work was to investigate the possibility of adding red mud, an alkaline leaching waste that is obtained from bauxite during the Bayer process for alumina production, in the raw meal of Portland cement mortars. The red mud is classified as dangerous, according to NBR 10004/2004, and world while generation reached over 117 million tons/year. This huge production requires high consuming products to be used as incorporation matrix and we studied the influence of red mud addition on the characteristics of cement mortars and concrete. In this paper the properties of Portland cement mortars incorporating high amounts of red mud was evaluated: pH variation, fresh (setting time, workability or normal consistency and water retention), and hardened state (mechanical strength, capillary water absorption, density and apparent porosity). Results seem promising for red mud additions up to 20 wt%. (author)

  11. Bone cements for percutaneous vertebroplasty and balloon kyphoplasty: Current status and future developments

    Directory of Open Access Journals (Sweden)

    Zhiwei He

    2015-01-01

    Full Text Available Osteoporotic vertebral compression fractures (OVCFs have gradually evolved into a serious health care problem globally. In order to reduce the morbidity of OVCF patients and improve their life quality, two minimally invasive surgery procedures, vertebroplasty (VP and balloon kyphoplasty (BKP, have been developed. Both VP and BKP require the injection of bone cement into the vertebrae of patients to stabilize fractured vertebra. As such, bone cement as the filling material plays an essential role in the effectiveness of these treatments. In this review article, we summarize the bone cements that are currently available in the market and those still under development. Two major categories of bone cements, nondegradable acrylic bone cements (ABCs and degradable calcium phosphate cements (CPCs, are introduced in detail. We also provide our perspectives on the future development of bone cements for VP and BKP.

  12. Study of commercial chemical additives for cementation of radioactive waste

    International Nuclear Information System (INIS)

    In this research it has been studied the effects of chemical additives (admixtures) in the cementation process of radioactive wastes, which are used to improve the properties of waste cementation process, both of the paste and of the solidified product. However there are a large variety of these materials that are frequently changed or taken out of the market, then it is essential to know the commercially available materials and their effects. The tests were carried out with a solution simulating the evaporator concentrate waste coming from PWR nuclear reactors. It was cemented using two formulations, A and B, incorporating higher or lower amount of waste, respectively. It was added chemical admixtures from two manufacturers (S and H), which were: accelerators, set retarders and superplasticizers. The experiments were organized by a factorial design 23. The measured parameters were the viscosity, the setting time, the paste and product density and the compressive strength. In this study we performed comparative analyzes of the results of compressive strength at age of 28 and 90 days and between the densities of the samples at the same ages. The compressive strength test at age of 28 days is considered a parameter essential issues related to security handling, transport and storage of cemented waste product. The results showed that the addition of accelerators improved the compressive strength of the cemented product, but presented lower values density products. (authors)

  13. Extraoral Cementation Technique to Minimize Cement-Associated Peri-implant Marginal Bone Loss: Can a Thin Layer of Zinc Oxide Cement Provide Sufficient Retention?

    Science.gov (United States)

    Frisch, Eberhard; Ratka-Krüger, Petra; Weigl, Paul; Woelber, Johan

    2016-01-01

    This report describes the use of laboratory-fabricated crown intaglio replicas for extraorally prepared cementation of fixed restorations to implants. This technique minimizes excess cement and may therefore reduce the risk of cement-related marginal peri-implant bone loss. It is unclear whether the remaining thin layer of luting agent provides sufficient retention if low-adhesive zinc oxide (ZnO) cement is used. In 85 consecutive patients, 113 single crowns were cemented to implants using extraoral cementation technique (ECT) and ZnO cement. All patients were followed for 6 months and investigated for decementation. Seven events of decementation (incidence: 6.19%) were found in 7 patients (8.24%). ECT may represent a viable cementation technique for implant-supported single crowns, even using low-adhesion cements. PMID:27479343

  14. Biological responses of brushite-forming Zn- and ZnSr- substituted beta-tricalcium phosphate bone cements

    Directory of Open Access Journals (Sweden)

    S Pina

    2010-09-01

    Full Text Available The core aim of this study was to investigate zinc (Zn- and zinc and strontium (ZnSr-containing brushite-forming beta-tricalcium phosphate (TCP cements for their effects on proliferation and differentiation of osteoblastic-like cells (MC3T3-E1 cell line as well as for their in vivo behaviour in trabecular bone cylindrical defects in a pilot study. In vitro proliferation and maturation responses of MC3T3-E1 osteoblastic-like cells to bone cements were studied at the cellular and molecular levels. The Zn- and Sr-containing brushite cements were found to stimulate pre-osteoblastic proliferation and osteoblastic maturation. Indeed, MC3T3-E1 cells exposed to the powdered cements had increased proliferative rates and higher adhesiveness capacity, in comparison to control cells. Furthermore, they exhibited higher alkaline phosphatase (ALP activity and increased Type-I collagen secretion and fibre deposition into the extracellular matrix. Proliferative and collagen deposition properties were more evident for cells grown in cements doped with Sr. The in vivo osteoconductive propertiesof the ZnCPC and ZnSrCPC cements were also pursued. Histological and histomorphometric analyses were performed at 1 and 2 months after implantation, using carbonated apatite cement (Norian SRS® as control. There was no evidence of cement-induced adverse foreign body reactions, and furthermore ZnCPC and ZnSrCPC cements revealed better in vivo performance in comparison to the control apatite cement. Additionally, the presence of both zinc and strontium resulted in the highest rate of new bone formation. These novel results indicate that the investigated ZnCPC and ZnSrCPC cements are both biocompatible and osteoconductive, being good candidate materials to use as bone substitutes.

  15. Disintegration of Bone Cement by Continuous and Pulsating Water Jet

    Czech Academy of Sciences Publication Activity Database

    Hloch, S.; Foldyna, Josef; Sitek, Libor; Zeleňák, Michal; Hlaváček, Petr; Hvizdoš, P.; Kloc, J.; Monka, P.; Monková, K.; Kozak, D.; Magurová, D.

    2013-01-01

    Roč. 20, č. 4 (2013), s. 593-598. ISSN 1330-3651 R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : bone cement * disintegration * water jet Subject RIV: JQ - Machines ; Tools Impact factor: 0.615, year: 2013 http://hrcak.srce.hr/index.php?show=clanak&id_clanak_jezik=157195

  16. Radiological Investigation of Bone Cement Layer Behaviour under Cyclic Loading

    Czech Academy of Sciences Publication Activity Database

    Kytýř, Daniel; Jiroušek, Ondřej; Dammer, J.

    Wuppertal : Institute static and dynamic of structures Bergischen Universitat Wuppertal, 2010 - (Harte, R.), s. 64-65 ISBN N. [Bilateral Czech/German Symposium /12./. Bremen (DE), 30.06.2010-03.07.2010] R&D Projects: GA ČR(CZ) GAP105/10/2305 Institutional research plan: CEZ:AV0Z20710524 Keywords : bone cement * cyclic loading * X-ray Subject RIV: FI - Traumatology, Orthopedics

  17. Osteogenesis Capacity of a Novel BMP/α-TCP Bioactive Composite Bone Cement

    Institute of Scientific and Technical Information of China (English)

    YANG Wei-zhong; ZHOU Da-li; YIN Shao-ya; YIN Guang-fu; GAO Li-da; ZHANG Yun

    2004-01-01

    To improve the osteogenesis ability of α-tricalcium phosphate (α-TCP) bone cement,a novel BMP/α-TCP composite bone cement was prepared.By measuring the setting time and compressive strength,the hydration characteristic of bone cement was evaluated.Animal experiments including histological observation,radiographic investigation as well as digital image analyses reveal the difference of osteogenesis ability among BMP,α-TCP bone cement and BMP/α-TCP composite bone cement.Results show that α-TCP bone cement possesses excellent hydration and setting properties as well as high mechanical property.Comparison experiments show that BMP/α-TCP composite bone cement has a stronger osteogenesis ability.The gross observation of the implant site does not exhibit any inflammation or necrosis.Histological analyses reveal that the material has good osteointegration with host bone,and new bone formation is detected within the materials,which are degrading.Strong osteogenesis ability of the composite is due to not only the excellent osteoconductive potential but also the osteoinductive potential contributed by active BMP releasing and the material degradation.Large skull defect could be well-healed by filling BMP/α-TCP composite bone cement.This novel material proves itself to be an absorbable and bioactive bone cement with an osteogenesis ability.

  18. Solid-state P-31 MR studies of bone mineral and calcium phosphate bone cements

    International Nuclear Information System (INIS)

    Calcium phosphate bone cements have recently been used to promote bone healing and remodeling, but little is known of their bioabsorption. The purpose of this paper to characterize and quantitate bone mineral and calcium phosphate bone cements with the use of solid-state P-31 NMR imaging to establish a model for bioabsorption studies. Pulverized cortical rabbit bone, octacalcium phosphate spherulites, and two synthetic apatite formulations (A and B, Norian, Mountain View, Calif) were evaluated in vitro. A 9.4-T Varian VXR-400S spectrometer operating at 161.9 MHz for P-31 was used to obtain NMR imaging spectra with the magic-angel spinning technique at a sample spin frequency of 6-7.5 kHz, utilizing an external 85% phosphoric acid reference. T1 was determined in a static 90 degrees τ 90 degrees experiment. Quantitation was attempted in mixed samples

  19. A Particle Model for Prediction of Cement Infiltration of Cancellous Bone in Osteoporotic Bone Augmentation.

    Directory of Open Access Journals (Sweden)

    Ehsan Basafa

    Full Text Available Femoroplasty is a potential preventive treatment for osteoporotic hip fractures. It involves augmenting mechanical properties of the femur by injecting Polymethylmethacrylate (PMMA bone cement. To reduce the risks involved and maximize the outcome, however, the procedure needs to be carefully planned and executed. An important part of the planning system is predicting infiltration of cement into the porous medium of cancellous bone. We used the method of Smoothed Particle Hydrodynamics (SPH to model the flow of PMMA inside porous media. We modified the standard formulation of SPH to incorporate the extreme viscosities associated with bone cement. Darcy creeping flow of fluids through isotropic porous media was simulated and the results were compared with those reported in the literature. Further validation involved injecting PMMA cement inside porous foam blocks - osteoporotic cancellous bone surrogates - and simulating the injections using our proposed SPH model. Millimeter accuracy was obtained in comparing the simulated and actual cement shapes. Also, strong correlations were found between the simulated and the experimental data of spreading distance (R(2 = 0.86 and normalized pressure (R(2 = 0.90. Results suggest that the proposed model is suitable for use in an osteoporotic femoral augmentation planning framework.

  20. Effect of cationic polyelectrolytes addition in cement cohesion

    OpenAIRE

    Edison Albert Zuluaga-Hernández; Bibian A Hoyos

    2014-01-01

    Here is studied the variation in cohesion of cement main phase (C-S-H) as a result of cationic polyelectrolytes addition (quaternary amines spermine and norspermidine). Cohesion study was carried out by molecular simulation techniques (Monte Carlo) using a primitive model in a canonical ensemble (NVT). The proposed model takes into account the influence of ionic size of each particle and the addition of polyelectrolytes with different charge number and separation. The results obtained show th...

  1. Cement mixtures containing copper tailings as an additive: durability properties

    OpenAIRE

    Obinna Onuaguluchi; Özgur Eren

    2012-01-01

    The effects of copper tailings as an additive, on some durability properties of cement mixtures were investigated. In each mixture, copper tailings addition levels by mass were 0%, 5% and 10%. Compared to the control samples, copper tailings blended pastes showed superior performance against autoclave expansion while insignificant decreases in sulfate resistance of mortars were observed. Copper tailings increased the water absorption and total permeable voids of concretes slightly. However, t...

  2. Using of borosilicate glass waste as a cement additive

    Science.gov (United States)

    Han, Weiwei; Sun, Tao; Li, Xinping; Sun, Mian; Lu, Yani

    2016-08-01

    Borosilicate glass waste is investigated as a cement additive in this paper to improve the properties of cement and concrete, such as setting time, compressive strength and radiation shielding. The results demonstrate that borosilicate glass is an effective additive, which not only improves the radiation shielding properties of cement paste, but also shows the irradiation effect on the mechanical and optical properties: borosilicate glass can increase the compressive strength and at the same time it makes a minor impact on the setting time and main mineralogical compositions of hydrated cement mixtures; and when the natural river sand in the mortar is replaced by borosilicate glass sand (in amounts from 0% to 22.2%), the compressive strength and the linear attenuation coefficient firstly increase and then decrease. When the glass waste content is 14.8%, the compressive strength is 43.2 MPa after 28 d and the linear attenuation coefficient is 0.2457 cm-1 after 28 d, which is beneficial for the preparation of radiation shielding concrete with high performances.

  3. Additives for cement compositions based on modified peat

    Science.gov (United States)

    Kopanitsa, Natalya; Sarkisov, Yurij; Gorshkova, Aleksandra; Demyanenko, Olga

    2016-01-01

    High quality competitive dry building mixes require modifying additives for various purposes to be included in their composition. There is insufficient amount of quality additives having stable properties for controlling the properties of cement compositions produced in Russia. Using of foreign modifying additives leads to significant increasing of the final cost of the product. The cost of imported modifiers in the composition of the dry building mixes can be up to 90% of the material cost, depending on the composition complexity. Thus, the problem of import substitution becomes relevant, especially in recent years, due to difficult economic situation. The article discusses the possibility of using local raw materials as a basis for obtaining dry building mixtures components. The properties of organo-mineral additives for cement compositions based on thermally modified peat raw materials are studied. Studies of the structure and composition of the additives are carried out by physicochemical research methods: electron microscopy and X-ray analysis. Results of experimental research showed that the peat additives contribute to improving of cement-sand mortar strength and hydrophysical properties.

  4. Additives for cement compositions based on modified peat

    Energy Technology Data Exchange (ETDEWEB)

    Kopanitsa, Natalya, E-mail: kopanitsa@mail.ru; Sarkisov, Yurij, E-mail: sarkisov@tsuab.ru; Gorshkova, Aleksandra, E-mail: kasatkina.alexandra@gmail.com; Demyanenko, Olga, E-mail: angel-n@sibmail.com [Tomsk State University of Architecture and Building, 2, Solyanaya sq., Tomsk, 634003 (Russian Federation)

    2016-01-15

    High quality competitive dry building mixes require modifying additives for various purposes to be included in their composition. There is insufficient amount of quality additives having stable properties for controlling the properties of cement compositions produced in Russia. Using of foreign modifying additives leads to significant increasing of the final cost of the product. The cost of imported modifiers in the composition of the dry building mixes can be up to 90% of the material cost, depending on the composition complexity. Thus, the problem of import substitution becomes relevant, especially in recent years, due to difficult economic situation. The article discusses the possibility of using local raw materials as a basis for obtaining dry building mixtures components. The properties of organo-mineral additives for cement compositions based on thermally modified peat raw materials are studied. Studies of the structure and composition of the additives are carried out by physicochemical research methods: electron microscopy and X-ray analysis. Results of experimental research showed that the peat additives contribute to improving of cement-sand mortar strength and hydrophysical properties.

  5. Microdamage assessment of bone-cement interfaces under monotonic and cyclic compression

    OpenAIRE

    Tozzi, Gianluca; Zhang, Qinghang; Tong, Jie

    2014-01-01

    Bone-cement interface has been investigated under selected loading conditions, utilising experimental techniques such as in situ mechanical testing and digital image correlation (DIC). However, the role of bone type in the overall load transfer and mechanical behaviour of the bone-cement construct is yet to be fully quantified. Moreover, microdamage accumulation at the interface and in the cement mantle has only been assessed on the exterior surfaces of the samples, where no volumetric inform...

  6. Influence of nano-dispersive modified additive on cement activity

    Science.gov (United States)

    Sazonova, Natalya; Badenikov, Artem; Skripnikova, Nelli; Ivanova, Elizaveta

    2016-01-01

    In the work the influence of single-walled carbon nanotubes (SWCNT) on the cement activity and the processes of structure formation of the hardened cement paste in different periods of hydration are studied. The changes in the kinetic curves of the sample strength growth modified with SWCNT in amount of 0.01 and 0.0005 % are stipulated by the results of differential scanning colorimetry, scanning electronic and ionic microscopy, X-ray-phase analysis. It was found that the nano-modified additive may increase in the axis compressive strength of the system by 1.4-6.3 fold relatively to the reference samples and may reach 179.6 MPa. It may intensify the hydration process of calcium silicates as well as influence on the matrix of hardened cement paste. The studies are conducted on the structural changes in the hardened cement paste, the time periods of increase and decrease of the compressive strength of the samples, the amount of the calcium hydroxide and tobermorite-like gel as well as the degree of hydration C3S and β-C2S.

  7. Influence of nano-dispersive modified additive on cement activity

    Energy Technology Data Exchange (ETDEWEB)

    Sazonova, Natalya, E-mail: n.a.sazonova@mail.ru; Badenikov, Artem, E-mail: rector@agta.ru; Ivanova, Elizaveta, E-mail: lisik-iva@mail.ru [Angarsk State Technical University, 60, Tchaykovsky St., 665835, Angarsk (Russian Federation); Skripnikova, Nelli, E-mail: nks2003@mail.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation)

    2016-01-15

    In the work the influence of single-walled carbon nanotubes (SWCNT) on the cement activity and the processes of structure formation of the hardened cement paste in different periods of hydration are studied. The changes in the kinetic curves of the sample strength growth modified with SWCNT in amount of 0.01 and 0.0005 % are stipulated by the results of differential scanning colorimetry, scanning electronic and ionic microscopy, X-ray-phase analysis. It was found that the nano-modified additive may increase in the axis compressive strength of the system by 1.4–6.3 fold relatively to the reference samples and may reach 179.6 MPa. It may intensify the hydration process of calcium silicates as well as influence on the matrix of hardened cement paste. The studies are conducted on the structural changes in the hardened cement paste, the time periods of increase and decrease of the compressive strength of the samples, the amount of the calcium hydroxide and tobermorite-like gel as well as the degree of hydration C{sub 3}S and β-C{sub 2}S.

  8. Cement mixtures containing copper tailings as an additive: durability properties

    Directory of Open Access Journals (Sweden)

    Obinna Onuaguluchi

    2012-12-01

    Full Text Available The effects of copper tailings as an additive, on some durability properties of cement mixtures were investigated. In each mixture, copper tailings addition levels by mass were 0%, 5% and 10%. Compared to the control samples, copper tailings blended pastes showed superior performance against autoclave expansion while insignificant decreases in sulfate resistance of mortars were observed. Copper tailings increased the water absorption and total permeable voids of concretes slightly. However, the compressive and flexural strengths of blended concretes were higher than those of the control samples. Similarly, improved resistance to acid attack and chloride penetration as the copper tailings content of concretes increased were also observed. Results further showed that the ASTM C 1202 rapid chloride permeability test may not be a valid indicator of chloride migration in mixtures containing conductive copper tailings. These results suggest that copper tailings can potentially enhance the durability properties of cement based materials.

  9. Calcium phosphate bone cement containing ABK and PLLA. Sustained release of ABK, the BMD of the femur in rats, and histological examination

    Energy Technology Data Exchange (ETDEWEB)

    Kusaka, T.; Tanaka, A.; Sasaki, S.; Takano, I.; Tahara, Y.; Ishii, Y. [Kyorin Univ., Tokyo (Japan). Dept. of Orhtopaedic Surgery

    2001-07-01

    Bone cement was prepared by mixing CPC95 (Mitsubishi Material Co., Ltd.), ABK, and PLLA at a ratio of 14 : 1 : 2. In vitro, Antibiotic sustained release tests were performed by the total amount exchange method. In animal experiments, the bone cement was infused into the right femur of 18-month-old female SD rats. After 1, 2, 4, or 6 months, the BMD was determined by DXA in the bilateral femoral bones. In addition, hard tissue specimens were prepared, and the state of bone formation was observed. The release of the antibiotic was 1.73 {mu}g/ml until 18 days after administration, maintaining a concentration over the MIC80 for MRSA. In the animal experiments, the BMD significantly increased after 2 - 4 months. In the hard tissue specimens, direct binding on the bone-cement interface and bone formation in the cement were observed after 1 month. (orig.)

  10. Recycling of copper tailings as an additive in cement mortars

    OpenAIRE

    Onuaguluchi, Obinna; EREN, Özgür

    2012-01-01

    Increasing demands for copper and copper allied products have made the processing of low grade ores with high volume waste output unavoidable. Presently, billions of tons of copper tailings can be found in major copper producing countries. The impact of copper tailings at 0%, 5% and 10% addition level by mass of cement on the fresh and hardened properties of mortars were determined. Results showed that dry copper tailings affect mixture consistency negatively. However, the use of pre-wetted t...

  11. The influence of clay additives in Portland cement on the compressive strength of the cement stone

    Directory of Open Access Journals (Sweden)

    A.R. Gaifullin

    2015-11-01

    Full Text Available The introduction of mineral additives to binders, especially to Portland cement, is one of the promising trends for solving the resource and energy saving problems, as well as problems of environmental protection during production and application. Expanding the supplementary cementitious materials resource base can be achieved through the use of natural pozzolans and thermally activated polymineral clays(commonly known as glinites in Russia. One type of glinite is metakaolin, which is obtained by calcination of kaolin clays. Metakaolin is widely and effectively used as a pozzolanic additive due to its beneficial effect on the physical and mechanical properties of Portland cement-based materials. The obstacle to its wide production and use are the limited deposits of pure kaolin clays in many countries, including the Russian Federation. In this respect, the studies of pozzolanic activity of the most common mineral clays and their use in some countries have significantly advanced. Similar studies were widely performed in the 1940s in USSR. It seems reasonable to renew this trend to provide a scientific base for the production of local pozzolans made of clays commonly used in different regions. Comparative studies of the effect of 5 clays differing in mineral and chemical composition, calcination temperature and specific surface area, and high-quality metakaolin, on the strength of hardened Portland cement paste have been performed. It has been established that introducing 5…10 % of composite clays calcined at 400…8000 C° and milled to a specific surface area of 290…800 m2/kg into Portland cement enhanced the strength of the hardened cement paste considerably better than the introduction of metakaolin with a specific surface area of 1200 m2/kg. The findings of the study suggest that many kinds of commonly used polymineral clays have a specific calcination temperature and dispersity, which results in a higher pozzolanic activity compared with

  12. Microdamage assessment of bone-cement interfaces under monotonic and cyclic compression.

    Science.gov (United States)

    Tozzi, Gianluca; Zhang, Qing-Hang; Tong, Jie

    2014-11-01

    Bone-cement interface has been investigated under selected loading conditions, utilising experimental techniques such as in situ mechanical testing and digital image correlation (DIC). However, the role of bone type in the overall load transfer and mechanical behaviour of the bone-cement construct is yet to be fully quantified. Moreover, microdamage accumulation at the interface and in the cement mantle has only been assessed on the exterior surfaces of the samples, where no volumetric information could be obtained. In this study, some typical bone-cement interfaces, representative of different fixation scenarios for both hip and knee replacements, were constructed using mainly trabecular bone, a mixture of trabecular and cortical bone and mainly cortical bone, and tested under static and cyclic compression. Axial displacement and strain fields were obtained by means of digital volume correlation (DVC) and microdamage due to static compression was assessed using DVC and finite element (FE) analysis, where yielded volumes and strains (εzz) were evaluated. A significantly higher load was transferred into the cement region when mainly cortical bone was used to interdigitate with the cement, compared with the other two cases. In the former, progressive damage accumulation under cyclic loading was observed within both the bone-cement interdigitated and the cement regions, as evidenced by the initiation of microcracks associated with high residual strains (εzz_res). PMID:25283468

  13. New developments in calcium phosphate bone cements: approaching spinal applications

    OpenAIRE

    Vlad, Maria Daniela

    2009-01-01

    La presente tesis doctoral (i.e., “New developments in calcium phosphate bone cements: approaching spinal applications”) aporta nuevos conocimientos en el campo de los cementos óseos de fosfato de calcio (CPBCs) en relación a su aplicación clínica en el campo de la cirugía vertebral mínimamente invasiva. La hipótesis central de esta investigación fue formulada en los siguientes términos: “Los cementos apatíticos pueden ser (si se optimizan) una alternativa mejor (debido a sus propiedades d...

  14. Preliminary study using pulsating water jet for bone cement demolition

    Czech Academy of Sciences Publication Activity Database

    Hloch, Sergej; Kloc, J.; Foldyna, Josef; Pude, F.; Smolko, I.; Zeleňák, Michal; Sitek, Libor; Hvizdoš, P.; Monka, P.; Monková, K.; Kozak, D.; Stoić, A.; Sedmak, A.; Milosevic, M.; Lehocká, D.; Mihalčinová, E.

    Ostrava : Ústav geoniky AV ČR, v.v.i, 2015 - (Sitek, L.; Klichová, D.), s. 37-54 ISBN 978-80-86407-56-2. [Vodní paprsek 2015 - výzkum, vývoj, aplikace. Velké Losiny (CZ), 06.10.2015-08.10.2015] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : bone cement * ultrasonic pulsating water jet * revision arthroplasty Subject RIV: JQ - Machines ; Tools

  15. Calcium phosphate cements properties with polymers addition; Propriedades do cimento de fosfato de calcio com adicao de polimeros

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, J.M.; Trajano, W.T.; Escobar, C.F.; Santos, L.A., E-mail: julianafernandes2@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil)

    2012-07-01

    Calcium phosphate cements (CPC) have attracted great interest to use in orthopedics and dentistry as replacements for damaged parts of the skeletal system, showing good biocompatibility and osseointegration, allowing its use as bone graft. Several studies have shown that the addition of polymer additives have a strong influence on the cement properties. The low mechanical strength is the main obstacle to greater use of CPC as an implant material. The objective of this study was to evaluate properties of a cement based on α-tricalcium phosphate (α-TCP), added polymers. PVA (10%, 8%, 6%), sodium alginate (2%) and polyacrylate ammonia (3%), all in weight, were added to the synthesized α-TCP powder. The samples were molded and evaluated for density, porosity in vitro test (Simulated Body Fluid), crystalline phases and mechanical strength. The results show increased the mechanical properties of the cement when added these polymers.

  16. Destruction of meat and bone meals in cement plants; Destruction des farines animales dans les cimenteries

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-10-01

    Following the crisis of the bovine spongiform encephalopathy disease ('mad cow' disease), the French cement industrialists have been requested by the government since 1996 to eliminate the forbidden meat and bone meals in cement kilns where they are used as fuel substitutes. This article presents the advantages of the cement industry file in the destruction of such wastes, the validation and the safety aspects of this process. Meat and bone meal represents a high-grade fuel that lowers the environmental impact of cement production and does not affect the quality of cement. (J.S.)

  17. An experimental approach to the study of the rheology behaviour of synthetic bone calcium phosphate cements

    Energy Technology Data Exchange (ETDEWEB)

    Friberg, J.; Fernandez, E.; Sarda, S.; Nilsson, M.; Ginebra, M.P.; Planell, J.A. [Universidad Politecnica de Catalunya, Barcelona (Spain). Dept. of Materials Science and Metallurgical Engineering; Martinez, S. [Barcelona Univ. (Spain). Mineralogia i Recursos Minerals

    2001-07-01

    Calcium phosphate cements were developed to fit surgical needs in biomedical fields such as odontology or traumatology. Nowadays, a broad field of new applications have been found for this kind of materials. Drug delivery systems, tissue-engineering scaffolds and osteoporotic bone filling applications are some of the new fields that are being benefited with these materials. Looking at both, commercial and new experimental calcium phosphate cements it is found that {alpha}-tricalcium phosphate is the main reactive powder responsible for the setting and the hardening of the cement. Thus, it is important to know how {alpha}-tricalcium phosphate affects injectability of these cements. The aim of this study was to investigate the rheological behaviour of {alpha}-tricalcium phosphate slurries in order to know how the cement injectability should be modified. Factors such as liquid to powder ratio, particle size of the main reactive powder and the addition of dispersants have been considered. The results showed that viscosity decreased when particle size of reactant was increased and when liquid to powder ratio was increased. It was also found that a minimum of viscosity exists at an optimum value of the weight percentage of dispersant. (orig.)

  18. Effect of process variables on the preparation of artificial bone cements

    Energy Technology Data Exchange (ETDEWEB)

    Santos Junior, J.G.F.; Melo, P.A.; Pinto, J.C., E-mail: pinto@peq.coppe.ufrj.br, E-mail: jjunior@peq.coppe.ufrj.br, E-mail: melo@peq.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Quimica; Pita, V.J.R.R., E-mail: vjpita@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Macromoleculas; Nele, M., E-mail: nele@eq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2013-10-15

    The present work concerns the preparation of bone cements based on poly(methyl methacrylate) (PMMA), used mainly for prosthesis fixation and cavity filling for correction of human bone failures. A typical bone cement recipe contains methyl methacrylate, which polymerizes in situ during cement application. An inherent problem of this reaction is the large amount of heat released during the cement preparation, which may lead to irreparable damage of living tissues. Optimization of PMMA-based bone cement recipes is thus an important step towards safe and reliable clinical usage of these materials. Important process variables related to the reaction temperature profile and the mixing of the recipe constituents were studied in order to allow for the adequate production of bone cements. It is shown that the average molar mass and size of the PMMA particles used in the production of the bone cement, as well as incorporation of radiopaque contrast, co-monomers and fillers into the bone recipe play fundamental roles in the course of the polymerization reaction. Furthermore, the injection vessel geometry may interfere dramatically with the temperature profile and the time for its occurrence. Finally, it has been observed that the morphology of the PMMA particles strongly affects the mixing of the bone cement components. (author)

  19. Effect of process variables on the preparation of artificial bone cements

    International Nuclear Information System (INIS)

    The present work concerns the preparation of bone cements based on poly(methyl methacrylate) (PMMA), used mainly for prosthesis fixation and cavity filling for correction of human bone failures. A typical bone cement recipe contains methyl methacrylate, which polymerizes in situ during cement application. An inherent problem of this reaction is the large amount of heat released during the cement preparation, which may lead to irreparable damage of living tissues. Optimization of PMMA-based bone cement recipes is thus an important step towards safe and reliable clinical usage of these materials. Important process variables related to the reaction temperature profile and the mixing of the recipe constituents were studied in order to allow for the adequate production of bone cements. It is shown that the average molar mass and size of the PMMA particles used in the production of the bone cement, as well as incorporation of radiopaque contrast, co-monomers and fillers into the bone recipe play fundamental roles in the course of the polymerization reaction. Furthermore, the injection vessel geometry may interfere dramatically with the temperature profile and the time for its occurrence. Finally, it has been observed that the morphology of the PMMA particles strongly affects the mixing of the bone cement components. (author)

  20. An injectable calcium phosphate cement for the local delivery of paclitaxel to bone

    NARCIS (Netherlands)

    Lopez-Heredia, M.A.; Kamphuis, G.J.; Thune, P.C.; Oner, F.C.; Jansen, J.A.; Walboomers, X.F.

    2011-01-01

    Bone metastases are usually treated by surgical removal, fixation and chemotherapeutic treatment. Bone cement is used to fill the resection voids. The aim of this study was to develop a local drug delivery system using a calcium phosphate cement (CPC) as carrier for chemotherapeutic agents. CPC cons

  1. Preparation and Characterization of Injectable Brushite Filled-Poly (Methyl Methacrylate) Bone Cement

    OpenAIRE

    Lucas C. Rodriguez; Jonathan Chari; Shant Aghyarian; Gindri, Izabelle M.; Victor Kosmopoulos; Rodrigues, Danieli C.

    2014-01-01

    Powder-liquid poly (methyl methacrylate) (PMMA) bone cements are widely utilized for augmentation of bone fractures and fixation of orthopedic implants. These cements typically have an abundance of beneficial qualities, however their lack of bioactivity allows for continued development. To enhance osseointegration and bioactivity, calcium phosphate cements prepared with hydroxyapatite, brushite or tricalcium phosphates have been introduced with rather unsuccessful results due to increased cem...

  2. Extended fatigue life of a catalyst-free self-healing acrylic bone cement using microencapsulated 2-octyl cyanoacrylate

    OpenAIRE

    Brochu, Alice B. W.; Matthys, Oriane B.; Craig, Stephen L.; Reichert, William M.

    2014-01-01

    The tissue adhesive 2-octyl cyanoacrylate (OCA) was encapsulated in polyurethane microshells and incorporated into bone cement to form a catalyst free, self-healing bone cement comprised of all clinically approved components. The bending strength, modulus, and fatigue lifetime were investigated in accordance with ASTM and ISO standards for the testing of PMMA bone cement. The bending strength of bone cement specimens decreased with increasing wt% capsules content for capsules without or with ...

  3. Signal-inducing bone cements for MRI-guided spinal cementoplasty: evaluation of contrast-agent-based polymethylmethacrylate cements

    International Nuclear Information System (INIS)

    The purpose of this work is to evaluate two signal-inducing bone cements for MRI-guided spinal cementoplasty. The bone cements were made of polymethylmethacrylate (PMMA, 5 ml monomeric, 12 g polymeric) and gadoterate meglumine as a contrast agent (CA, 0-40 μl) with either saline solution (NaCl, 2-4 ml) or hydroxyapatite bone substitute (HA, 2-4 ml). The cement's signal was assessed in an open 1-Tesla MR scanner, with T1W TSE and fast interventional T1W TSE pulse sequences, and the ideal amount of each component was determined. The compressive and bending strength for different amounts of NaCl and HA were evaluated. The cement's MRI signal depended on the concentration of CA, the amount of NaCl or HA, and the pulse sequence. The signal peaks were recorded between 1 and 10 μl CA per ml NaCl or HA, and were higher in fast T1W TSE than in T1W TSE images. The NaCl-PMMA-CA cements had a greater MRI signal intensity and compressive strength; the HA-PMMA-CA cements had a superior bending strength. Concerning the MR signal and biomechanical properties, these cements would permit MRI-guided cementoplasty. Due to its higher signal and greater compressive strength, the NaCl-PMMA-CA compound appears to be superior to the HA-PMMA-CA compound. (orig.)

  4. Calcium phosphate cement delivering zoledronate decreases bone turnover rate and restores bone architecture in ovariectomized rats

    International Nuclear Information System (INIS)

    Patients sustaining bony fractures frequently require the application of bone graft substitutes to fill the bone defects. In the meantime, anti-osteoporosis drugs may be added in bone fillers to treat osteoporosis, especially in postmenopausal women and the elderly. The effects of zoledronate-impregnated calcium phosphate cement (ZLN/CPC) on ovariectomized (OVX) rats were evaluated. OVX rats were implanted with ZLN/CPC, containing 0.025 mg ZLN in the greater omentum. Afterward the clinical sign of toxicity was recorded for eight weeks. The rats were sacrificed and blood samples were collected for hematology and serum bone turnover markers analyses. The four limbs of the rats were harvested and micro-computer tomography (micro-CT) scanning and bone ash analyses were performed. No clinical toxicity was observed in the treated rats. Compared to the OVX rats, levels of bone resorption markers (fragments of C-telopeptides of type I collagen) and bone formation markers (alkaline phosphatase and osteocalcin) decreased significantly in the treated rats. Osteopontin, which mediates the anchoring of osteoclasts to the mineral matrix of bones, also decreased significantly. Micro-CT scanning and histologic examinations of the distal femoral metaphyses showed that the cancellous bone architectures were restored, with a concomitant decrease in bone porosity. The bone mineral content in the bone ashes also increased significantly. This study indicates that ZLN-impregnated CPC reduces bone turnover rate and restores bone architecture in OVX rats. CPC may be an appropriate carrier to deliver drugs to treat osteoporosis, and this approach may also reduce rates of post-dosing symptoms for intravenous ZLN delivery. (paper)

  5. Porous calcium phosphate-poly (lactic-co-glycolic) acid composite bone cement: A viable tunable drug delivery system.

    Science.gov (United States)

    Roy, Abhijit; Jhunjhunwala, Siddharth; Bayer, Emily; Fedorchak, Morgan; Little, Steve R; Kumta, Prashant N

    2016-02-01

    Calcium phosphate based cements (CPCs) are frequently used as bone void fillers for non-load bearing segmental bone defects due to their clinically relevant handling characteristics and ability to promote natural bone growth. Macroporous CPC scaffolds with interconnected pores are preferred for their ability to degrade faster and enable accelerated bone regeneration. Herein, a composite CPC scaffold is developed using newly developed resorbable calcium phosphate cement (ReCaPP) formulation containing degradable microspheres of bio-compatible poly (lactic-co-glycolic acid) (PLGA) serving as porogen. The present study is aimed at characterizing the effect of in-vitro degradation of PLGA microspheres on the physical, chemical and structural characteristics of the composite cements. The porosity measurements results reveal the formation of highly interconnected macroporous scaffolds after degradation of PLGA microspheres. The in-vitro characterizations also suggest that the degradation by products of PLGA reduces the pH of the local environment thereby increasing the dissolution rate of the cement. In addition, the in-vitro vancomycin release from the composite CPC scaffold suggests that the drug association with the composite scaffolds can be tuned to achieve control release kinetics. Further, the study demonstrates control release lasting for longer than 10weeks from the composite cements in which vancomycin is encapsulated in PLGA microspheres. PMID:26652353

  6. Intrusion Characteristics of Three Bone Cements for Tibial Component of Total Knee Arthroplasty in a Cadaveric Bone Model.

    Science.gov (United States)

    Walden, Justin K; Chong, Alexander C M; Dinh, Nam L; Adrian, Scott; Cusick, Robert; Wooley, Paul H

    2016-01-01

    The purpose of this study was to evaluate and compare the intrusion characteristics of Simplex-HV to Simplex-P and Palacos-R in cadaveric proximal tibial bone. Eighteen fresh-frozen cadaver proximal tibiae were examined with standard arthroplasty tibial cuts. Each tibia was randomly assigned to receive one of the three bone cements for use with finger packing technique. Sagittal sections were prepared and analyzed using digital photography and stereoscopic micrographs to evaluate cement intrusion characteristics. The cement penetration depth was measured from the tibial bone cut surface, which did not include the cement thickness under the tibial base plate. Significant differences were detected in the bone cement penetration between the three cements. Penetration was increased using the Simplex-HV (average, 2.7 mm; range, 2.0-3.0 mm) compared with Simplex-P (average, 2.2 mm) and Palacos-R (average, 1.8 mm). These depths approximate to 3.7, 3.2, and 2.8 mm of total cement penetration, respectively. The data suggest that high-viscosity bone cement may provide good fixation of the tibial component of a total knee arthroplasty when using the finger packing technique. PMID:27518289

  7. DETERMINATION OF DIPOLE MOMENTS IN PLASTICIZER ADDITIONS FOR CEMENT CONCRETES

    Directory of Open Access Journals (Sweden)

    P. I. Ioukhnevsky

    2010-01-01

    Full Text Available The paper contains a method for determination of dipole moments in chemical plasticizer addition molecules for cement concretes as in powder-state so in the form of aqueous solutions as well.The methodology is based on measuring dielectric substance  permittivity depending on temperature, construction of a diagram (ε – 1/(ε + 2 = f(1/T with subsequent calculation of the molecule dipole moment. The Ossipov’s formula has been used for aqueous solutions of super-plasticizer additions with the purpose to calculate a dipole moment of polar substance in the polar solvent.The obtained values of dipole moments in C-3 super-plasticizer addition molecule are in good agreement with the values obtained as a result of quantum-chemical calculations. 

  8. CT evaluation of local leakage of bone cement after percutaneous kyphoplasty and vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Jae; Choi, A. Lam; Yie, Mi-Yeon; Yoon, Ji Young; Jeon, Eui Yong; Koh, Sung Hye; Yoon, Dae Young; Lim, Kyung Ja (Dept. of Radiology, Hallym Univ. Sacred Heart Hospital, Seoul (Korea)), e-mail: ijlee2003@medimail.co.kr; Im, Hyoung June (Dept. of Occupational Medicine, Hallym Univ. College of Medicine, Seoul (Korea))

    2010-07-15

    Background: Percutaneous injection of bone cement (acrylic cement) during percutaneous kyphoplasty and vertebroplasty can cause symptomatic or asymptomatic complications due to leakage, extravasation or vascular migration of cement. Purpose: To investigate and to compare the incidence and site of local leakage or complications of bone cement after percutaneous kyphoplasty and vertebroplasty using bone cement. Material and Methods: We retrospectively reviewed 473 cases of percutaneous kyphoplasty or vertebroplasty performed under fluoroscopic guidance. Of the 473 cases, follow-up CT scans that covered the treated bones were available for 83 cases (59 kyphoplasty and 24 vertebroplasty). Results: The rate of local leakage of bone cement was 87.5% (21/24) for percutaneous vertebroplasty and 49.2% (29/59) for kyphoplasty. The most common site of local leakage was perivertebral soft tissue (n=8, 38.1%) for vertebroplasty. The most common site of local leakage was a perivertebral vein (n=7, 24.1%) for kyphoplasty. Two cases of pulmonary cement embolism developed: one case after kyphoplasty and one case after vertebroplasty. Conclusion: Local leakage of bone cement was more common for percutaneous vertebroplasty compared with kyphoplasty (P<0.005). The most common sites of local leakage were perivertebral soft tissue and perivertebral vein.

  9. Bone cement/layered double hydroxide nanocomposites as potential biomaterials for joint implant.

    Science.gov (United States)

    Kapusetti, Govinda; Misra, Nira; Singh, Vakil; Kushwaha, R K; Maiti, Pralay

    2012-12-01

    Poly(methyl methacrylate)-based bone cement and layered double hydroxide (LDH) nanocomposites have been used as a grouting material for total joint arthroplasty. Few weight percentage of nanoLDH was uniformly dispersed in the bone cement matrix to have adequate interaction with matrix polymer. Mechanical strength, stiffness, toughness, and fatigue resistance of the nanocomposites are found to be higher than that of pure bone cement. Nanocomposites are thermally stable as compared to pristine bone cement. Direct mixing of the nanoLDH without any organic solvent makes these nanocomposites biocompatible. Biocompatibility was evaluated and compared with that of commercial bone cement by measuring hydrophilic nature, hemolysis assay, thrombosis assay, and deposition of apatite in simulated body fluid immersion. Finally, the viability of human osteoblast cells on the above developed nanocomposites was testified for actual biocompatibility. The experiment showed better cell growth in nanocomposites as compared to pure bone cement. Thus, these nanocomposites are found to be better grouting material than bone cement. PMID:22733710

  10. Recycling Jorf Lasfar fly ash as an additive to cement

    Directory of Open Access Journals (Sweden)

    Hamadi A

    2012-09-01

    Full Text Available Recycling fly ash is a good example of valorization of waste. It gives a solution the environmental problem by avoiding land filling, and reducing CO2 emission in the atmosphere. In this work we studied the physical-chemical characteristics of Jorf Lasfar fly ash. The parameters investigated were particle size, density, specific surface Blaine, chemical and mineralogical compositions. The techniques used are scanning electronic microscope (SEM, transmission electronic microscope (TEM, X-rays fluorescence (XRF, X-rays diffraction (XRD and atomic spectrometry emission coupled with inductive plasma ICP. We also conducted a study on the mechanical behavior of type CPJ45 cements produced from a combined grinding of clinker, limestone and gypsum. The substitution of a portion of the clinker by different percentages of fly ash was conducted. We noticed that the compression and bending resistances for these mixtures went through a maximum at 28 days with the addition of 7% (by mass of ash. This result showed that the mineral and chemical compositions of this ash conferred a Pozzoulanic power to the cement studied.

  11. Radioactive bone cement for the treatment of spinal metastases: a dosimetric analysis of simulated clinical scenarios

    Science.gov (United States)

    Kaneko, T. S.; Sehgal, V.; Skinner, H. B.; Al-Ghazi, M. S. A. L.; Ramsinghani, N. S.; Marquez Miranda, M.; Keyak, J. H.

    2012-07-01

    Vertebral metastases are a common manifestation of many cancers, potentially leading to vertebral collapse and neurological complications. Conventional treatment often involves percutaneous vertebroplasty/kyphoplasty followed by external beam radiation therapy. As a more convenient alternative, we have introduced radioactive bone cement, i.e. bone cement incorporating a radionuclide. In this study, we used a previously developed Monte Carlo radiation transport modeling method to evaluate dose distributions from phosphorus-32 radioactive cement in simulated clinical scenarios. Isodose curves were generally concentric about the surface of bone cement injected into cadaveric vertebrae, indicating that dose distributions are relatively predictable, thus facilitating treatment planning (cement formulation and dosimetry method are patent pending). Model results indicated that a therapeutic dose could be delivered to tumor/bone within ∼4 mm of the cement surface while maintaining a safe dose to radiosensitive tissue beyond this distance. This therapeutic range should be sufficient to treat target volumes within the vertebral body when tumor ablation or other techniques are used to create a cavity into which the radioactive cement can be injected. With further development, treating spinal metastases with radioactive bone cement may become a clinically useful and convenient alternative to the conventional two-step approach of percutaneous strength restoration followed by radiotherapy.

  12. Gentamicin release from commercially-available gentamicin-loaded PMMA bone cements in a prosthesis-related interfacial gap model and their antibacterial efficacy

    Directory of Open Access Journals (Sweden)

    van der Mei Henny C

    2010-11-01

    Full Text Available Abstract Background Around about 1970, a gentamicin-loaded poly (methylmethacrylate (PMMA bone cement brand (Refobacin Palacos R was introduced to control infection in joint arthroplasties. In 2005, this brand was replaced by two gentamicin-loaded follow-up brands, Refobacin Bone Cement R and Palacos R + G. In addition, another gentamicin-loaded cement brand, SmartSet GHV, was introduced in Europe in 2003. In the present study, we investigated differences in gentamicin release and the antibacterial efficacy of the eluent between these four cement brands. Methods 200 μm-wide gaps were made in samples of each cement and filled with buffer in order to measure the gentamicin release. Release kinetics were related to bone cement powder particle characteristics and wettabilities of the cement surfaces. Gaps were also inoculated with bacteria isolated from infected prostheses for 24 h and their survival determined. Gentamicin release and bacterial survival were statistically analysed using the Student's t-test. Results All three Palacos variants showed equal burst releases but each of the successor Palacos cements showed significantly higher sustained releases. SmartSet GHV showed a significantly higher burst release, while its sustained release was comparable with original Palacos. A gentamicin-sensitive bacterium did not survive in the high gentamicin concentrations in the interfacial gaps, while a gentamicin-resistant strain did, regardless of the type of cement used. Survival was independent of the level of burst release by the bone cement. Conclusions Although marketed as the original gentamicin-loaded Palacos cement, orthopaedic surgeons should be aware that the successor cements do not appear to have the same release characteristics as the original one. Overall, high gentamicin concentrations were reached inside our prosthesis-related interfacial gap model. These concentrations may be expected to effectively decontaminate the prosthesis

  13. Analysis of changes in bone cement damping factor and its effect on bone load

    Directory of Open Access Journals (Sweden)

    P. Postawa

    2007-07-01

    Full Text Available Purpose: The article presents the results of simulations and material-related investigations for bone cement used for alloplasty of hip joint. Mechanical properties of bone cements are of key importance for a successful surgery and further use of the joint as well as its behaviour during complex load which appears during patient’s walk.Design/methodology/approach: One of the methods of thermal analysis for polymeric materials has been used for investigations. DMTA method is based on the analysis of the signal (reaction from the deformed material under particular conditions, at the changeable ambient temperature as well as frequency and amplitude of vibrations. DMTA thermograms give information on change in storage modulus E’ and the mechanical loss factor tgδ, which is responsible for dissipation of energy during deformation.Findings: During simulation investigations ADINA engineering environment has been used; it enabled, at the assumed boundary and initial conditions, to assess the stress which appears in individual cross-sections of the analysed bone and the implant fixed by means of bone cement. During the analysis the cross-sections have been presented and the values of the stress which appears in individual zones have been determined.Research limitations/implications: Due to high complexity, only the results of simulation software have been used, clinic trials will be possible not before thorough check and analysis of the obtained results.Practical implications: Practical application of the results of the investigations described in this paper will be possible after long and comprehensive clinical trials.Originality/value: Original value of this paper are the results of tests since such an analysis has never been conducted by scientific environment working on this subject.

  14. Aluminum-free glass-ionomer bone cements with enhanced bioactivity and biodegradability

    International Nuclear Information System (INIS)

    Al-free glasses of general composition 0.340SiO2:0.300ZnO:(0.250-a-b)CaO:aSrO:bMgO:0.050Na2O:0.060P2O5 (a, b = 0.000 or 0.125) were synthesized by melt quenching and their ability to form glass-ionomer cements was evaluated using poly(acrylic acid) and water. We evaluated the influence of the poly(acrylic acid) molecular weight and glass particle size in the cement mechanical performance. Higher compressive strength (25 ± 5 MPa) and higher compressive elastic modulus (492 ± 17 MPa) were achieved with a poly(acrylic acid) of 50 kDa and glass particle sizes between 63 and 125 μm. Cements prepared with glass formulation a = 0.125 and b = 0.000 were analyzed after immersion in simulated body fluid; they presented a surface morphology consistent with a calcium phosphate coating and a Ca/P ratio of 1.55 (similar to calcium-deficient hydroxyapatite). Addition of starch to the cement formulation induced partial degradability after 8 weeks of immersion in phosphate buffer saline containing α-amylase. Micro-computed tomography analysis revealed that the inclusion of starch increased the cement porosity from 35% to 42%. We were able to produce partially degradable Al-free glass-ionomer bone cements with mechanical performance, bioactivity and biodegradability suitable to be applied on non-load bearing sites and with the appropriate physical characteristics for osteointegration upon partial degradation. Zn release studies (concentrations between 413 μM and 887 μM) evidenced the necessity to tune the cement formulations to reduce the Zn concentration in the surrounding environment. Highlights: ► We developed partially degradable, bioactive, Al-free glass-ionomer cements (GICs). ► Enhanced mechanical behavior was achieved using 63–125 μm glass particle size range. ► The highest mechanical resistance was obtained using poly(acrylic acid) of 50 kDa. ► Biodegradation was successfully tuned to start 8 weeks after GIC preparation. ► Zn release should be tuned to

  15. Aluminum-free glass-ionomer bone cements with enhanced bioactivity and biodegradability

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Filipa O.; Pires, Ricardo A., E-mail: rpires@dep.uminho.pt; Reis, Rui L.

    2013-04-01

    Al-free glasses of general composition 0.340SiO{sub 2}:0.300ZnO:(0.250-a-b)CaO:aSrO:bMgO:0.050Na{sub 2}O:0.060P{sub 2}O{sub 5} (a, b = 0.000 or 0.125) were synthesized by melt quenching and their ability to form glass-ionomer cements was evaluated using poly(acrylic acid) and water. We evaluated the influence of the poly(acrylic acid) molecular weight and glass particle size in the cement mechanical performance. Higher compressive strength (25 ± 5 MPa) and higher compressive elastic modulus (492 ± 17 MPa) were achieved with a poly(acrylic acid) of 50 kDa and glass particle sizes between 63 and 125 μm. Cements prepared with glass formulation a = 0.125 and b = 0.000 were analyzed after immersion in simulated body fluid; they presented a surface morphology consistent with a calcium phosphate coating and a Ca/P ratio of 1.55 (similar to calcium-deficient hydroxyapatite). Addition of starch to the cement formulation induced partial degradability after 8 weeks of immersion in phosphate buffer saline containing α-amylase. Micro-computed tomography analysis revealed that the inclusion of starch increased the cement porosity from 35% to 42%. We were able to produce partially degradable Al-free glass-ionomer bone cements with mechanical performance, bioactivity and biodegradability suitable to be applied on non-load bearing sites and with the appropriate physical characteristics for osteointegration upon partial degradation. Zn release studies (concentrations between 413 μM and 887 μM) evidenced the necessity to tune the cement formulations to reduce the Zn concentration in the surrounding environment. Highlights: ► We developed partially degradable, bioactive, Al-free glass-ionomer cements (GICs). ► Enhanced mechanical behavior was achieved using 63–125 μm glass particle size range. ► The highest mechanical resistance was obtained using poly(acrylic acid) of 50 kDa. ► Biodegradation was successfully tuned to start 8 weeks after GIC preparation. ► Zn

  16. Wear and Mechanical Properties of Various Bone Cements – Influence of Saline Environment

    Czech Academy of Sciences Publication Activity Database

    Balko, J.; Fides, M.; Sedlák, R.; Hvizdoš, P.; Hloch, Sergej; Kloc, J.; Monka, P.

    -, č. 662 (2015), s. 147-150. ISSN 1662-9795 Institutional support: RVO:68145535 Keywords : wear * saline * hardness * bone cement Subject RIV: JQ - Machines ; Tools http://www.scientific.net/KEM.662.147

  17. Mechanical and cytotoxicity testing of acrylic bone cement embedded with microencapsulated 2-octyl cyanoacrylate

    OpenAIRE

    Brochu, Alice B.W.; Gregory A. Evans; Reichert, William M.

    2013-01-01

    The water-reactive tissue adhesive 2-octyl cyanoacrylate (OCA) was microencapsulated in polyurethane shells and incorporated into Palacos R bone cement. The tensile and compressive properties of the composite material were investigated in accordance with commercial standards, and fracture toughness of the capsule-embedded bone cement was measured using the tapered double-cantilever beam geometry. Viability and proliferation of MG63 human osteosarcoma cells after culture with extracts from Pal...

  18. Cemented total hip arthroplasty with impacted morcellized bone-grafts to restore acetabular bone defects in congenital hip dysplasia.

    NARCIS (Netherlands)

    Bolder, S.B.T.; Melenhorst, J.; Gardeniers, J.W.M.; Slooff, T.J.J.H.; Veth, R.P.H.; Schreurs, B.W.

    2001-01-01

    We evaluated the results of 27 acetabular reconstructions in 21 patients with secondary osteoarthritis resulting from congenital dysplasia of the hip in which the acetabular bone defects were restored with impacted morcellized bone-grafts in combination with a cemented cup. At an average follow-up o

  19. Effect of Combined Calcium Hydroxide and Accelerated Portland Cement on Bone Formation and Soft Tissue Healing in Dog Bone Lesions

    Directory of Open Access Journals (Sweden)

    Khorshidi H

    2015-09-01

    Full Text Available Statement of Problem: Recent literatures show that accelerated Portland cement (APC and calcium hydroxide Ca (OH2 may have the potential to promote the bone regeneration. However, certain clinical studies reveal consistency of Ca (OH2, as one of the practical drawbacks of the material when used alone. To overcome such inconvenience, the combination of the Ca (OH2 with a bone replacement material could offer a convenient solution. Objectives: To evaluate the soft tissue healing and bone regeneration in the periodontal intrabony osseous defects using accelerated Portland cement (APC in combination with calcium hydroxide Ca (OH2, as a filling material. Materials and Methods: Five healthy adult mongrel dogs aged 2-3 years old (approximately 20 kg in weight with intact dentition and healthy periodontium were selected for this study. Two one-wall defects in both mesial and distal aspects of the 3rd premolars of both sides of the mandible were created. Therefore, four defects were prepared in each dog. Three defects in each dog were randomly filled with one of the following materials: APC alone, APC mixed with Ca (OH2, and Ca (OH2 alone. The fourth defect was left empty (control. Upon clinical examination of the sutured sites, the amount of dehiscence from the adjacent tooth was measured after two and eight weeks, using a periodontal probe mesiodistally. For histometric analysis, the degree of new bone formation was estimated at the end of the eighth postoperative week, by a differential point-counting method. The percentage of the defect volume occupied by new osteoid or trabecular bone was recorded. Results: Measurement of wound dehiscence during the second week revealed that all five APCs had an exposure of 1-2 mm and at the end of the study all samples showed 3-4 mm exposure across the surface of the graft material, whereas the Ca (OH2, control, and APC + Ca (OH2 groups did not show any exposure at the end of the eighth week of the study. The most

  20. MR predictors of bone cement leakage in patients receiving percutaneous vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Young Hwan; Han, Dae Hee; Choi, Young Ho; Cha, Joo Hee [Boramae Hospital, Incheon (Korea, Republic of); Jun, Deuk Soo; Jin, Wook; Kim, Hyung Sik [Gachon Medicine School, Gachon (Korea, Republic of)

    2005-07-15

    To identify MR predictors of bone cement leakage in patients receiving percutaneous vertebroplasty. Percutaneous vertebroplasties were performed in 45 vertebras (T7; one, T8; two, T10; two, T11; two, T12; eight, L1; fifteen, L2; eight, L3; five, L4; two) in 35 patients (age 52-83). The procedure was performed using an 11 G Jamshidi needle, which was inserted into the target by the bipedicular approach. Kyphoplasty, unilateral pedicular approach and extrapedicular approach cases were excluded. Shortly after the procedure, all patients underwent a noncontrast CT covering the vertebroplasty sites. A retrospective study was performed to determine whether cement leakage is related to any of following MR findings: presence of cortical disruption of the vertebral body, severity of body compression (proportion of abnormal to normal vertebral body volumes), bone cement amount, bone cement amount/severity of body compression ratio, proportion of low-signal area in a vertebral body on T1 weighted image, presence of either vacuum or cystic portion below a linear dark signal in a fractured vertebra, and the location of dark signal intensity line in a vertebral body. Logisgic discrimination model stepwise method was used in the statistical analysis. On post-vertebroplasty CT scan, bone cement leakage was detected in or around 29 vertebrae (64%), including 11 vertebrae (24%) where leakage was found in the epidural space or radial vein. No patient displayed any neurological symptoms or signs. The most frequent site of bone cement leakage was the anterior external vertebral venous plexus (49%). Endplate cortical bone disruption was related to an increased risk of intervertebral bone cement leakage ({rho} < 0.05). Bone cement leakage tended to occur less frequently when there is a vacuum or cystic change below the dark linear signal intensity in a fractured vertebra ({rho} < 0.05). No other MR findings showed a statistically significant correlation with bone cement leakage. On pre

  1. A new acoustic method to determine the setting time of calcium sulfate bone cement mixed with antibiotics

    International Nuclear Information System (INIS)

    A new method is described which can be used to determine the setting times of small amounts of high value bone cements. The test was developed to measure how the setting times of a commercially available synthetic calcium sulfate cement (Stimulan, Biocomposites, UK) in two forms (standard and Rapid Cure) varies with the addition of clinically relevant antibiotics. The importance of being able to accurately quantify these setting times is discussed. The results demonstrate that this new method, which is shown to correlate to the Vicat needle, gives reliable and repeatable data with additional benefits expressed in the article. The majority of antibiotics mixed were found to retard the setting reaction of the calcium sulfate cement. (paper)

  2. Metakaolin sand – a promising addition for Portland cement

    Directory of Open Access Journals (Sweden)

    Janotka, I.

    2010-06-01

    Full Text Available The kaolin sand resource at the Vyšný Petrovec quarry in Slovakia comes to a total of 20 megatonnes. The metakaolin material obtained by heating kaolin sand at 650 ºC contains from 31.5 to 40% (wt metakaolinite, as well as illite, muscovite, quartz and feldspar. The aim of this study was to verify whether this calcined sand (MK1 is a pozzolanic material and characterize the cements and mortars prepared with it. The hydration reactions taking place in the blends were assessed with conduction calorimetry, X-ray diffraction (XRD and differential thermal analysis-thermogravimetry (DTA-TG. Blend and mortar strength development and pore structure were also evaluated. The results obtained showed that this metakaolin sand (MK-1 is a pozzolanic material apt for use as a cement addition and for making mortars.

    Las reservas de arena caolínica de la cantera eslovaca de Vyšný Petrovec ascienden a un total de 20 millones de toneladas. El material metacaolínico, que resulta al calentar la arena caolínica a 650 ºC, contiene entre un 31,5 y un 40% de metacaolinita, además de ilita, moscovita, cuarzo y feldespato. El objetivo de este estudio ha sido comprobar que esa arena calcinada es un material puzolánico; así como caracterizar los cementos y morteros preparados con dicha arena (MK-1. La hidratación de las mezclas se evaluó mediante calorimetría de conducción, y difracción de rayos X (DRX y Análisis térmico-diferencial y termogravimétrico (ATD-TG. Se ha evaluado el desarrollo resistente de las mezclas y morteros; así como su estructura porosa. Los resultados obtenidos han demostrado que esa arena metacolínica (MK-1 es un material puzolánico y que podría utilizarse como adición al cemento y en la preparación de morteros.

  3. Effect of additive particles on mechanical, thermal, and cell functioning properties of poly(methyl methacrylate cement

    Directory of Open Access Journals (Sweden)

    Khandaker M

    2014-05-01

    Full Text Available Morshed Khandaker,1 Melville B Vaughan,2 Tracy L Morris,3 Jeremiah J White,1 Zhaotong Meng1 1Department of Engineering and Physics, 2Department of Biology, 3Department of Mathematics and Statistics, University of Central Oklahoma, Edmond, OK, USA Abstract: The most common bone cement material used clinically today for orthopedic surgery is poly(methyl methacrylate (PMMA. Conventional PMMA bone cement has several mechanical, thermal, and biological disadvantages. To overcome these problems, researchers have investigated combinations of PMMA bone cement and several bioactive particles (micrometers to nanometers in size, such as magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica. A study comparing the effect of these individual additives on the mechanical, thermal, and cell functional properties of PMMA would be important to enable selection of suitable additives and design improved PMMA cement for orthopedic applications. Therefore, the goal of this study was to determine the effect of inclusion of magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica additives in PMMA on the mechanical, thermal, and cell functional performance of PMMA. American Society for Testing and Materials standard three-point bend flexural and fracture tests were conducted to determine the flexural strength, flexural modulus, and fracture toughness of the different PMMA samples. A custom-made temperature measurement system was used to determine maximum curing temperature and the time needed for each PMMA sample to reach its maximum curing temperature. Osteoblast adhesion and proliferation experiments were performed to determine cell viability using the different PMMA cements. We found that flexural strength and fracture toughness were significantly greater for PMMA specimens that incorporated silica than for the other specimens. All additives prolonged the time taken to reach maximum curing temperature and significantly improved cell

  4. Comparison of a quasi-dynamic and a static extraction method for the cytotoxic evaluation of acrylic bone cements.

    Science.gov (United States)

    Hoess, A; López, A; Engqvist, H; Ott, M Karlsson; Persson, C

    2016-05-01

    In this study, two different extraction approaches were compared in order to evaluate the cytotoxicity of 7 different acrylic bone cements, mainly developed for spinal applications, to osteoblastic cells. Firstly, a static extraction was carried out continuously over 24h, a method widely used in literature. Secondly, a quasi-dynamic extraction method that allowed the investigation of time-dependent cytotoxic effects of curing acrylic bone cements to cells was introduced. In both cases the extraction of the cements was started at a very early stage of the polymerization process to simulate the conditions during clinical application. Data obtained by the quasi-dynamic extraction method suggest that the cytotoxicity of the setting materials mainly originates from the release of toxic components during the first hour of the polymerization reaction. It was also shown that a static extraction over 24h generally represents this initial stage of the curing process. Furthermore, compared to the static extraction, time-dependent cytotoxicity profiles could be detected using the quasi-dynamic extraction method. Specifically, a modification of commercial OsteopalV with castor oil as a plasticizer as well as a customized cement formulation showed clear differences in cytotoxic behavior compared to the other materials during the setting process. In addition, it was observed that unreacted monomer released from the castor oil modified cement was not the main component affecting the toxicity of the material extracts. The quasi-dynamic extraction method is a useful tool to get deeper insight into the cytotoxic potential of curing acrylic bone cements under relevant biological conditions, allowing systematic optimization of materials under development. PMID:26952424

  5. Microencapsulation of 2-octylcyanoacrylate tissue adhesive for self-healing acrylic bone cement.

    Science.gov (United States)

    Brochu, Alice B W; Chyan, William J; Reichert, William M

    2012-10-01

    Here, we report the first phase of developing self-healing acrylic bone cement: the preparation and characterization of polyurethane (PUR) microcapsules containing a medical cyanoacrylate tissue adhesive. Capsules were prepared by interfacial polymerization of a toluene-2,4-diisocyanate-based polyurethane prepolymer with 1,4-butanediol to encapsulate 2-octylcyanoacrylate (OCA). Various capsule characteristics, including: resultant morphology, average size and size distribution, shell thickness, content and reactivity of encapsulated agent, and shelf life are investigated and their reliance on solvent type and amount, surfactant type and amount, temperature, pH, agitation rate, reaction time, and mode of addition of the oil phase to the aqueous phase are presented. Capsules had average diameters ranging from 74 to 222 μm and average shell thicknesses ranging from 1.5 to 6 μm. The capsule content was determined via thermogravimetric analysis and subsequent analysis of the capsules following up to 8 weeks storage revealed minimal loss of core contents. Mechanical testing of OCA-containing capsules showed individual capsules withstood compressive forces up to a few tenths of Newtons, and the contents released from crushed capsules generated tensile adhesive forces of a few Newtons. Capsules were successfully mixed into the poly(methyl methacrylate) bone cement, surviving the mixing process, exposure to methyl methacrylate monomer, and the resulting exothermic matrix curing. PMID:22807313

  6. Preparation and Compressive Strength of Calcium Phosphate Bone Cement Containing N, O-carboxymethyl Chitosan

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    N, O-carboxymethyl chitosan ( CMCTS ), a kind of biodegradable organic substance, was added to calcium phosphate bone cement (CPC) to produce a composite more similar in composition to human bone. The compressive strength of the new material was increased by 10 times compared with conventional CPC.

  7. Injectable bioactive calcium-magnesium phosphate cement for bone regeneration

    International Nuclear Information System (INIS)

    Novel injectable and degradable calcium-magnesium phosphate cement (CMPC) with rapid-setting characteristic was developed by the introduction of magnesium phosphate cement (MPC) into calcium phosphate cement (CPC). The calcium-magnesium phosphate cement prepared under the optimum P/L ratio exhibited good injectability and desired workability. It could set within 10 min at 37 0C in 100% relative humidity and the compressive strength could reach 47 MPa after setting for 48 h, indicating that the prepared cement has relatively high initial mechanical strength. The results of in vitro degradation experiments demonstrated the good degradability of the injectable CMPC, and its degradation rate occurred significantly faster than that of pure CPC in simulated body fluid (SBF) solution. It can be concluded that the novel injectable calcium-magnesium phosphate cement is highly promising for a wide variety of clinical applications, especially for the development of minimally invasive techniques.

  8. Amino acid-assisted synthesis of strontium hydroxyapatite bone cement by a soft solution freezing method

    Indian Academy of Sciences (India)

    D Gopi; S Nithiya; L Kavitha; J M F Ferreira

    2012-12-01

    Among many cations that can substitute for calcium in the structure of hydroxyapatite, strontium provokes an increasing interest because of its beneficial effect on bone formation and prevention of bone resorption. Strontium-incorporated calcium phosphates show potential in biomedical application, particularly the doped strontium may help in new bone formation. We have synthesized strontium hydroxyapatite powders at 2 °C by a soft solution freezing method using glycine as the template. The structural and morphological characterizations were carried out on the as obtained powders using Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy techniques. Strontium was quantitatively incorporated into hydroxyapatite where its substitution for calcium provoked a linear shift of the infrared absorption bands of the hydroxyl and phosphate groups. The strontium substituted bone cement has potential for use in orthopaedic surgeries. The present study shows that the addition of glycine plays an important role in reducing the particle size of strontium hydroxyapatite which could be used for biomedical applications.

  9. Lignin-based cement fluid loss control additive

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, P.

    1990-05-22

    This patent describes a hydraulic cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and from abut 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been sequentially crosslinked by reacting the lignin with a member of the group consisting of formaldehyde and epichlorohydrin and alkoxylated with between about 2 to about 6 moles of a compound selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and a combination thereof per 1000 g of the lignin.

  10. Wollastonite nanofiber–doped self-setting calcium phosphate bioactive cement for bone tissue regeneration

    Directory of Open Access Journals (Sweden)

    Guo H

    2012-07-01

    Full Text Available Han Guo,1,2 Jie Wei,2 Wenhua Song,2 Shan Zhang,2 Yonggang Yan,3 Changsheng Liu,2 Tiqiao Xiao11Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, People's Republic of China; 2Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People's Republic of China; 3School of Physical Science and Technology, Sichuan University, Chengdu, People's Republic of ChinaAbstract: The purpose of this study was to synthesize a self-setting bioactive cement by incorporation of wollastonite nanofibers (WNFs into calcium phosphate cement (CPC. The composition, morphology, setting time, compressive strength, hydrophilicity, and degradation of WNF-doped CPC (wnf-CPC were investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and inductively coupled plasma atomic emission spectroscopy were utilized. Additionally, methyl-thiazolyl-tetrazolium bromide assay, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, and histological evaluation were used to study the cell and tissue responses to wnf-CPC, both in vitro and in vivo. The results confirmed that the addition of WNFs into CPC had no obvious effect on the setting time or the compressive strength of wnf-CPC, provided the WNF amount was not more than 10 wt%. However, the hydrophilicity and degradability of wnf-CPC were significantly improved by the addition of WNFs – this was because of the change of microstructure caused by the WNFs. The preferred dissolution of WNFs caused the formation of microporosity in wnf-CPC when soaked in tris hydrochloride solution. The microporosity enlarged the surface area of the wnf-CPC and so promoted degradation of the wnf-CPC when in contact with liquid. In addition, MG-63 cell attachment and proliferation on the wnf-CPC were superior to that on the CPC, indicating that

  11. Study of effect of addition of fly ash on radon exhalation rate in cement samples

    International Nuclear Information System (INIS)

    Most of the building materials like cement and fly ash contain naturally occurring radioactive materials (NORM). Increased interest in measuring radon exhalation rate in building products is due to the concern about health hazards of NORM. This paper focuses on studying the effect of addition of fly ash on radon exhalation rate in cement samples. Ordinary Portland Cement (OPC) and coal fly ash were used for finding the exhalation rate of cement in this paper. To study the effect on exhalation rate of cement, fly ash is added in different proportions to cement samples. The measurement was conducted by CAN Technique using SSNTDs. A gradual increase has been observed in radon exhalation rate up to certain proportion and then start to decrease. (author)

  12. Influence of artificially-induced porosity on the compressive strength of calcium phosphate bone cements.

    Science.gov (United States)

    Mouzakis, Dionysios; Zaoutsos, Stefanos Polymeros; Bouropoulos, Nikolaos; Rokidi, Stamatia; Papanicolaou, George

    2016-07-01

    The biological and mechanical nature of calcium phosphate cements (CPC's) matches well with that of bone tissues, thus they can be considered as an appropriate environment for bone repair as bone defect fillers. The current study focuses on the experimental characterization of the mechanical properties of CPCs that are favorably used in clinical applications. Aiming on evaluation of their mechanical performance, tests in compression loading were conducted in order to determine the mechanical properties of the material under study. In this context, experimental results occurring from the above mechanical tests on porous specimens that were fabricated from three different porous additives, namely albumin, gelatin and sodium alginate, are provided, while assessment of their mechanical properties in respect to the used porous media is performed. Additionally, samples reinforced with hydroxyapatite crystals were also tested in compression and the results are compared with those of the above tested porous CPCs. The knowledge obtained allows the improvement of their biomechanical properties by controlling their structure in a micro level, and finds a way to compromise between mechanical and biological response. PMID:26945808

  13. Biomechanical and finite element analyses of bone cement-Injectable cannulated pedicle screw fixation in osteoporotic bone.

    Science.gov (United States)

    Liu, Yaoyao; Xu, Jianzhong; Sun, Dong; Luo, Fei; Zhang, Zehua; Dai, Fei

    2016-07-01

    The objectives of this study were to investigate the safety and biomechanical stability of a polymethylmethacrylate (PMMA)-augmented bone cement-injectable cannulated pedicle screw (CICPS) in cancellous bone model, and to analyze the stress distribution at the screw-cement-bone interface. The OMEGA cannulated pedicle screw (OPS) and conventional pedicle screw (CPS) were used as control groups. Safety of the CICPS was evaluated by the static bending and bending fatigue tests. Biomechanical stability was analyzed by the maximum axial pullout strength and maximum torque tests. Stress distribution at the screw-cement-bone interface was analyzed by the finite element (FE) method. The CICPS and CPS produced statistically similar values for bending stiffness, bending structural stiffness, and bending yield moment. The maximum pullout force was 53.47 ± 8.65 N in CPS group, compared to 130.82 ± 7.32 N and 175.45 ± 43.01 N in the PMMA-augmented OPS and CICPS groups, respectively (p screw-cement-bone interface in the CICPS group. In conclusion, PMMA-augmentation with CICPS may be a potentially useful method to increase the stability of pedicle screws in patients with osteoporosis. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 960-967, 2016. PMID:25976272

  14. Electrical properties of Portland cement, with the addition of polypropylene fibres - regarding durability

    OpenAIRE

    Richardson, Alan

    2004-01-01

    This paper makes a comparison between the electrical properties of cement grout with and without monofilament polypropylene fibre additions. The findings show a small, but significant difference between the electrolytic transport properties of cement grout with monofilament polypropylene fibre additions when compared to grout without fibre additions. The grout with fibre additions suggests a reduced probability of water and ion transmission, due to higher measured resistivity, which will resu...

  15. THE INFLUENCE OF THE COMPLEX CHEMICAL ADDITIVE CONTAINING THE STRUCTURED CARBON NANOMATERIAL ON PROPERTIES OF CEMENT

    Directory of Open Access Journals (Sweden)

    O. Yu. Sheyda

    2015-01-01

    Full Text Available The paper presents results of investigations on influence of domestic complex chemical additive containing structured carbon nanomaterial and characterized by a combination effect (curing acceleration and plasticizing on cement and cement stone properties. The purpose of the investigations, on the one hand, has been to confirm efficacy of УКД-1additive from the perspective for increasing the rate of gain, strength growth of cement concrete and additive influence on setting time with the purpose to preserve molding properties of concrete mixes in time, and on the other hand, that is to assess “mechanism” of the УКД-1 additive action in the cement concrete. The research results have revealed regularities in changes due to the additive of water requirements and time period of the cement setting. The reqularities are considered as a pre-requisite for relevant changes in molding properties of the concrete mixes. The paper also experimentally substantiates the possibility to decrease temperature of cement concrete heating with the УДК-1 additive. It has been done with the purpose to save energy resources under production conditions. In addition to this the paper proves the efficiency of the additive which is expressed in strength increase of cement stone up to 20–40 % in the rated age (28 days that is considered as a basis for strength growth of cement concrete. The paper confirms a hypothesis on physical nature of this phenomenon because the X-ray phase analysis method has shown that there are no changes in morphology of portland cement hydration products under the action of the additive agent containing a structured carbon nanomaterial. Results of theoretical and experimental investigations on УКД-1 additive efficiency have been proved by industrial approbation while fabricating precast concrete products and construction of monolithic structures under plant industrial conditions (Minsk, SS “Stroyprogress” JSC MAPID and on

  16. Influence of liquid phase on physical properties of the new triphasic bone cement

    OpenAIRE

    A. Ślósarczyk; N. Osypanka; J. Czechowska; Z. Paszkiewicz; A. Zima

    2012-01-01

    Purpose: The aim of this work was to develop a new bone cement based on hydroxyapatite (HAp), βTCP and calcium sulfate hemihydrate (CSH) and to determine the influence of a liquid phase, used for cement pastes preparation, on physical properties of the final implant material.Design/methodology/approach: The powder phase consisting of CSH (60 wt.%) and HAp+ βTCP (40 wt.%) was applied. Composite samples were prepared using distilled water, chitosan and methylcellulose solutions as the liquid ph...

  17. Effect of vacuum-treatment on deformation properties of PMMA bone cement.

    Science.gov (United States)

    Zivic, Fatima; Babic, Miroslav; Grujovic, Nenad; Mitrovic, Slobodan; Favaro, Gregory; Caunii, Mihaela

    2012-01-01

    Deformation behavior of polymethyl methacrylate (PMMA) bone cement is explored using microindentation. Two types of PMMA bone cement were prepared. Vacuum treated samples were subjected to the degassing of the material under vacuum of 270 mbar for 35 s, followed by the second degassing under vacuum of 255 mbar for 35 s. Air-cured samples were left in ambient air to cool down and harden. All samples were left to age for 6 months before the test. The samples were then subjected to the indentation fatigue test mode, using sharp Vickers indenter. First, loading segment rise time was varied in order to establish time-dependent behavior of the samples. Experimental data showed that viscous part of the deformation can be neglected under the observed test conditions. The second series of microindentation tests were realized with variation of number of cycles and indentation hardness and modulus were obtained. Approximate hardness was also calculated using analysis of residual impression area. Porosity characteristics were analyzed using CellC software. Scanning electron microscopy (SEM) analysis showed that air-cured bone cement exhibited significant number of large voids made of aggregated PMMA beads accompanied by particles of the radiopaque agent, while vacuum treated samples had homogeneous structure. Air-cured samples exhibited variable hardness and elasticity modulus throughout the material. They also had lower hardness values (approximately 65-100 MPa) than the vacuum treated cement (approximately 170 MPa). Porosity of 5.1% was obtained for vacuum treated cement and 16.8% for air-cured cement. Extensive plastic deformation, microcracks and craze whitening were produced during indentation of air-cured bone cement, whereas vacuum treated cement exhibited no cracks and no plastic deformation. PMID:22100087

  18. The Mechanical Behavior of Bone Cement in THR in the Presense of Cavities

    Directory of Open Access Journals (Sweden)

    A. Benouis

    2014-06-01

    Full Text Available In this work we analyze three-dimensionally using the finite element method, the level and the Von Mises stress equivalent distribution induced around a cavity and between two cavities located in the proximal and distal bone cement polymethylmethacrylate (PMMA. The effects of the position around two main axes (vertical and horizontal of the cavity with respect to these axes, of the cavity - cavity interdistance and of the type of loading (static on the mechanical behavior of cement orthopedic are highlighted. We show that the breaking strain of the cement is largely taken when the cement in its proximal-lateral part contains cavities very close adjacent to each other. This work highlights not only the effect of the density of cavities, in our case simulated by cavity-cavity interdistance, but also the nature of the activity of the patient (patient standing corresponding to static efforts on the mechanical behavior of cement.

  19. Reinforcement of bone cement around prostheses by pre-coated wire coil: a preliminary study.

    Science.gov (United States)

    Kim, J K; Park, J B

    1994-01-01

    The longevity of the cemented total hip joint replacement depends on the integrity of the cement fixation with respect to the interfaces of the metal stem and bone, and stress/strain transmission and its distribution. A simple coil made of stainless steel wires was placed around a tapered stem in a simulated cement mantle to counteract the radial- and hoop-stress and static push-out mechanical tests were performed. The results show statistically significant increases in ultimate strain (+17.62%), ultimate load (+110.34%), stiffness (+117.63%), and fracture toughness (+153.63%) exhibited by the wire reinforcement over the control. Precoating with thin layer of polymethylmethacrylate may also enhance the mechanical properties of the reinforced cement mantle. This simple device may contribute to the longevity of the cement mantle by virtue of the enhanced mechanical properties, which in turn will be able to absorb more energy transmitted through the metal stem. PMID:8000291

  20. Monitoring of hardening and hygroscopic induced strains in a calcium phosphate bone cement using FBG sensor.

    Science.gov (United States)

    Bimis, A; Karalekas, D; Bouropoulos, N; Mouzakis, D; Zaoutsos, S

    2016-07-01

    This study initially deals with the investigation of the induced strains during hardening stage of a self-setting calcium phosphate bone cement using fiber-Bragg grating (FBG) optical sensors. A complementary Scanning Electron Microscopy (SEM) investigation was also conducted at different time intervals of the hardening period and its findings were related to the FBG recordings. From the obtained results, it is demonstrated that the FBG response is affected by the microstructural changes taking place when the bone cement is immersed into the hardening liquid media. Subsequently, the FBG sensor was used to monitor the absorption process and hygroscopic response of the hardened and dried biocement when exposed to a liquid/humid environment. From the FBG-based calculated hygric strains as a function of moisture concentration, the coefficient of moisture expansion (CME) of the examined bone cement was obtained, exhibiting two distinct linear regions. PMID:26807773

  1. In vitro biocompatibility of chitosan/hyaluronic acid-containing calcium phosphate bone cements.

    Science.gov (United States)

    Hesaraki, Saeed; Nezafati, Nader

    2014-08-01

    The need for bone repair has increased as the population ages. In this research, calcium phosphate cements, with and without chitosan (CS) and hyaluronic acid (HA), were synthesized. The composition and morphological properties of cements were evaluated by X-ray diffraction and scanning electron microscopy. The acellular in vitro bioactivity revealed that different apatite morphologies were formed on the surfaces of cements after soaking in simulated body fluid. The in vitro osteoblastic cell biocompatibility of in situ forming cements was evaluated and compared with those of conventional calcium phosphate cements (CPCs). The viability and growth rate of the cells were similar for all CPCs, but better alkaline phosphatase activity was observed for CPC with CS and HA. Calcium phosphate cements supported attachment of osteoblastic cells on their surfaces. Spindle-shaped osteoblasts with developed cytoplasmic membrane were found on the surfaces of cement samples after 7 days of culture. These results reveal the potential of the CPC-CS/HA composites to be used in bone tissue engineering. PMID:24399509

  2. Performance of bioactive PMMA-based bone cement under load-bearing conditions: an in vivo evaluation and FE simulation.

    Science.gov (United States)

    Fottner, Andreas; Nies, Berthold; Kitanovic, Denis; Steinbrück, Arnd; Mayer-Wagner, Susanne; Schröder, Christian; Heinemann, Sascha; Pohl, Ulrich; Jansson, Volkmar

    2016-09-01

    In the past, bioactive bone cement was investigated in order to improve the durability of cemented arthroplasties by strengthening the bone-cement interface. As direct bone-cement bonding may theoretically lead to higher stresses within the cement, the question arises, whether polymethylmethacrylate features suitable mechanical properties to withstand altered stress conditions? To answer this question, in vivo experiments and finite element simulations were conducted. Twelve rabbits were divided into two groups examining either bioactive polymethylmethacrylate-based cement with unchanged mechanical properties or commercially available polymethylmethacrylate cement. The cements were tested under load-bearing conditions over a period of 7 months, using a spacer prosthesis cemented into the femur. For the finite element analyses, boundary conditions of the rabbit femur were simulated and analyses were performed with respect to different loading scenarios. Calculations of equivalent stress distributions within the cements were applied, with a completely bonded cement surface for the bioactive cement and with a continuously interfering fibrous tissue layer for the reference cement. The bioactive cement revealed good in vivo bioactivity. In the bioactive cement group two failures (33 %), with complete break-out of the prosthesis occurred, while none in the reference group. Finite element analyses of simulated bioactive cement fixation showed an increase in maximal equivalent stress by 49.2 to 109.4 % compared to the simulation of reference cement. The two failures as well as an increase in calculated equivalent stress highlight the importance of fatigue properties of polymethylmethacrylate in general and especially when developing bioactive cements designated for load-bearing conditions. PMID:27530301

  3. Contact damage failure analyses of fretting wear behavior of the metal stem titanium alloy-bone cement interface.

    Science.gov (United States)

    Zhang, Lanfeng; Ge, Shirong; Liu, Hongtao; Wang, Qingliang; Wang, Liping; Xian, Cory J

    2015-11-01

    Although cemented titanium alloy is not favored currently in the Western world for its poor clinical and radiography outcomes, its lower modulus of elasticity and good biocompatibility are instrumental for its ability supporting and transforming physical load, and it is more suitable for usage in Chinese and Japanese populations due to their lower body weights and unique femoral characteristics. Through various friction tests of different cycles, loads and conditions and by examining fretting hysteresis loops, fatigue process curves and wear surfaces, the current study investigated fretting wear characteristics and wear mechanism of titanium alloy stem-bone cement interface. It was found that the combination of loads and displacement affected the wear quantity. Friction coefficient, which was in an inverse relationship to load under the same amplitude, was proportional to amplitudes under the same load. Additionally, calf serum was found to both lubricate and erode the wear interface. Moreover, cement fatigue contact areas appeared black/oxidative in dry and gruel in 25% calf serum. Fatigue scratches were detected within contact areas, and wear scars were found on cement and titanium surfaces, which were concave-shaped and ring concave/ convex-shaped, respectively. The coupling of thermoplastic effect and minimal torque damage has been proposed to be the major reason of contact damage. These data will be important for further studies analyzing metal-cement interface failure performance and solving interface friction and wear debris production issues. PMID:26241891

  4. Recycling of red muds with the extraction of metals and special additions to cement

    Science.gov (United States)

    Zinoveev, D. V.; Diubanov, V. G.; Shutova, A. V.; Ziniaeva, M. V.

    2015-01-01

    The liquid-phase reduction of iron oxides from red mud is experimentally studied. It is shown that, in addition to a metal, a slag suitable for utilization in the construction industry can be produced as a result of pyrometallurgical processing of red mud. Portland cement is shown to be produced from this slag with mineral additions and a high-aluminate expansion addition to cement.

  5. MR findings predictive of intradiscal leakage of bone cement in vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kye Ho; Yoo, Dong Soo; Kim, You Me; Lee, Young Seok [Donkook University College of Medicine, Cheonan (Korea, Republic of)

    2007-04-15

    To evaluate the relation between pre-operative MR findings and intradiscal bone cement leakage. Pre-operative MR and vertebroplasty were performed in 188 vertebral bodies, 376 superior and inferior cortical endplates and intervertebral discs of 126 patients. We analyzed the relation between endplate cortical injury and intradiscal linear low signal intensity lesions in the pre-operative MR images and measured intradiscal bone cement leakage on post-operative CT and fluoroscopy. Intradiscal bone cement leakage was found in 11.4% (43/376) of the cases. The incidence of endplate cortical injury in T1, T2 weighted MR images were 52.1% and 38.8%, respectively; the incidence of intradiscal linear low signal intensity lesions in T1, T2 weighted images were 11.2% and 24.2%, respectively. In relation with pre-operative MR findings and intradiscal bone cement leakage, the sensitivities of end plate cortical injury in T1 and T2 weighted images and intradiscal low signal intensity lesions in T1 and T2 weighted images were 100%, 95.3%, 39.5%, 86.5% the specificities were 54.1%, 68.5%, 92.5%, 83.9%, the positive predictive values were 21.9%, 28.1%, 40.5%, 40.7%, the negative predictive values were 100%, 99.1%, 92.2%, 97.9% and the accuracy were 59.3%, 71.5%, 86.4%, 84.0%. The incidence of intradiscal bone cement leakage was significantly increased when endplate cortical injury and intradiscal linear low signal intensity lesions were observed ({rho} < 0.001). Endplate cortical injury and intradiscal linear low signal intensity observed in pre-operative MR are useful findings in predicting intradiscal bone cement leakage.

  6. Implant augmentation: adding bone cement to improve the treatment of osteoporotic distal femur fractures: a biomechanical study using human cadaver bones.

    Science.gov (United States)

    Wähnert, Dirk; Hofmann-Fliri, Ladina; Richards, R Geoff; Gueorguiev, Boyko; Raschke, Michael J; Windolf, Markus

    2014-11-01

    The increasing problems in the field of osteoporotic fracture fixation results in specialized implants as well as new operation methods, for example, implant augmentation with bone cement. The aim of this study was to determine the biomechanical impact of augmentation in the treatment of osteoporotic distal femur fractures.Seven pairs of osteoporotic fresh frozen distal femora were randomly assigned to either an augmented or nonaugmented group. In both groups, an Orthopaedic Trauma Association 33 A3 fractures was fixed using the locking compression plate distal femur and cannulated and perforated screws. In the augmented group, additionally, 1 mL of polymethylmethacrylate cement was injected through the screw. Prior to mechanical testing, bone mineral density (BMD) and local bone strength were determined. Mechanical testing was performed by cyclic axial loading (100 N to 750 N + 0.05N/cycle) using a servo-hydraulic testing machine.As a result, the BMD as well as the axial stiffness did not significantly differ between the groups. The number of cycles to failure was significantly higher in the augmented group with the BMD as a significant covariate.In conclusion, cement augmentation can significantly improve implant anchorage in plating of osteoporotic distal femur fractures. PMID:25415673

  7. The effect of bone cement particles on the friction of polyethylene and polyurethane knee bearings

    International Nuclear Information System (INIS)

    Compliant layer knee joints have been considered for use in an attempt to increase the serviceable life of artificial joints. If designed correctly, these joints should operate within the full-fluid film lubrication regime. However, adverse tribological conditions, such as the presence of bone and bone cement particles, may breach the fluid film and cause surface wear. The frictional behaviour of both polyurethane (PU) and conventional polyethylene (PE) tibial components against a metallic femoral component was therefore assessed when bone cement particles were introduced into the lubricant. The bone cement particles caused a large increase in the frictional torque of both the PE and PU bearings; however, the friction produced by the PU bearings was still considerably lower than that produced by the PE bearings. The volume of bone cement particles between each of the bearings and the resultant frictional torque both decreased over time. This occurred more quickly with the PE bearings but greater damage was caused to the surface of the PE bearings than the PU components

  8. The effect of bone cement particles on the friction of polyethylene and polyurethane knee bearings

    Energy Technology Data Exchange (ETDEWEB)

    Ash, H E [Centre for Biomedical Engineering, University of Durham, Durham DH1 3LE (United Kingdom); Scholes, S C [Centre for Biomedical Engineering, University of Durham, Durham DH1 3LE (United Kingdom); Unsworth, A [Centre for Biomedical Engineering, University of Durham, Durham DH1 3LE (United Kingdom); Jones, E [Stryker Howmedica Osteonics, Raheen Industrial Estate, Limerick (Ireland)

    2004-08-07

    Compliant layer knee joints have been considered for use in an attempt to increase the serviceable life of artificial joints. If designed correctly, these joints should operate within the full-fluid film lubrication regime. However, adverse tribological conditions, such as the presence of bone and bone cement particles, may breach the fluid film and cause surface wear. The frictional behaviour of both polyurethane (PU) and conventional polyethylene (PE) tibial components against a metallic femoral component was therefore assessed when bone cement particles were introduced into the lubricant. The bone cement particles caused a large increase in the frictional torque of both the PE and PU bearings; however, the friction produced by the PU bearings was still considerably lower than that produced by the PE bearings. The volume of bone cement particles between each of the bearings and the resultant frictional torque both decreased over time. This occurred more quickly with the PE bearings but greater damage was caused to the surface of the PE bearings than the PU components.

  9. Histological and biomechanical studies of two bone colonizable cements in rabbits.

    Science.gov (United States)

    Lu, J X; About, I; Stephan, G; Van Landuyt, P; Dejou, J; Fiocchi, M; Lemaître, J; Proust, J P

    1999-08-01

    We have developed two colonizable bone cements: the first is a partially resorbable bisphenol-alpha-glycidyl methacrylate (Bis-GMA)-based cement (PRC) and the second is a calcium phosphate cement (CPC). PRC is composed of aluminous silanized ceramic and particles of a bioresorbable polymer embedded in a matrix of Bis-GMA. CPC consisted of tricalcium phosphate, monocalcium phosphate monohydrate, dicalcium phosphate dihydrate, and xanthane. Both cements were implanted into cavities drilled in rabbit femoral and tibial condyles. After 2, 4, 12, and 24 weeks of implantation, histological observations and biomechanical tests were performed. With CPC, a progressive osteointegration with a concomitant biodegradation in the presence of macrophages were observed. The mechanical study revealed a decrease of the compressive strength until the 4th week, followed by a slight increase. There was a general decrease in the elastic modulus with time. Moreover, by week 4, the histological study showed that the new bone was in direct contact with CPC margins. No inflammation was observed during the observation period. With PRC, the osteointegration as well as the biodegradation were slight, but its compressive strength was higher than that of cancellous bone and CPC (p < 0.05) at all observation periods. Its elastic modulus was greater than that of cancellous bone and CPC until the 4th week, then fell under the values of the cancellous bone. PMID:10458273

  10. Polyelectrolyte addition effect on the properties of setting hydraulic cements based on calcium phosphate

    International Nuclear Information System (INIS)

    In the present work the effects of the addition of some poly electrolytes (sodium alginate and poly acrylic acid) on the solubility, crystalline phases, pH and mechanical strength under compression of three calcium phosphate cements were studied. (author)

  11. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    Science.gov (United States)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  12. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    Science.gov (United States)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  13. Combination of bone cement filling and plate internal fixation with limb salvage is used for metastatic malignant bone tumors☆

    Institute of Scientific and Technical Information of China (English)

    Yang Jun; Yu Bin; Guo Xin-hui; Yang Peng; Zhang Kai-rui; Zhang Sheng; Cai Wei-bin; Ku Jian-bin; Tian Ling-yan

    2013-01-01

    BACKGROUND:Currently, limb salvage therapy has become the standard treatment of malignant bone tumors way, but improper treatments wil result in tumor recurrence, secondary infection, internal fixation or prosthesis loosening. OBJECTIVE:Based on the traditional surgical principle for metastatic bone tumors of the limbs, this study designed a user-friendly, individualized, simplistic pal iative treatment regimen from the actual conditions of patients to observe the reasonability, clinical efficacy and prognosis of bone cement fil ing combined with internal fixation in the treatment of metastatic malignant bone tumors. METHODS:Thirty-one patients with metastatic malignant bone tumors who required salvage treatment were screened from the Department of Orthopedics, the 421 Hospital of Chinese PLA, and their clinical data were retrospectively analyzed. Al the 31 patients were divided into two groups:tumor removal+internal fixation group (non-chemoradiotherapy group, n=11) treated with bone cement fil ing plus plate internal fixation (pal iative treatment);tumor removal+internal fixation+chemoradiotherapy group (chemoradiotherapy group, n=20), treated with radiotherapy before internal fixation plus plate internal fixation with limb salvage. The fol ow-up period was 4-38 months, averagely 18 months. RESULTS AND CONCLUSION:The fol ow-up results showed that in the non-chemoradiotherapy group, al the 11 patients survived, who could live independently and have good motor functions;in the chemoradiotherapy group, 17 of the 20 patients survived and the rest three patients died of tumor metastasis, their poor conditions and complications at 9 and 13 months after internal fixation. In patients undergoing tumor removal+plate internal fixation with limb salvage, the integrated scores for nerve and motor functions were increased by more than level 1. These findings confirm that a simple pal iative therapy of bone cement fil ing and internal fixation without chemoradiotherapy is

  14. The behavior of biogenic silica-rich rocks and volcanic tuffs as pozzolanic additives in cement

    Science.gov (United States)

    Fragoulis, Dimitris; Stamatakis, Michael; Anastasatou, Marianthi

    2015-04-01

    Cements currently produced, include a variety of pozzolanic materials, aiming for lower clinker addition and utilization of vast deposits of certain raw materials and/or mining wastes and byproducts. The major naturally occurring pozzolanic materials include glassy tuffs, zeolitic tuffs, diatomites and volcanic lavas rich in glassy phase, such as perlites. Therefore, based on the available raw materials in different locations, the cement composition might vary according to the accessibility of efficient pozzolanic materials. In the present investigation, the behavior of pozzolanic cements produced with representative samples of the aforementioned materials was studied, following the characterization of the implemented pozzolanas with respect to their chemical and mineralogical characteristics. Laboratory cements were produced by co-grinding 75% clinker, 5% gypsum and 20% pozzolana, for the same period of time (45 min). Regarding pozzolanic materials, four different types of pozzolanas were utilized namely, diatomite, perlite, zeolite tuff and glassy tuff. More specifically, two diatomite samples originated from Australia and Greece, with high and low reactive silica content respectively, two perlite samples originated from Turkey and from Milos Island, Greece, with different reactive silica contents, a zeolite tuff sample originated from Turkey and a glassy tuff sample originated from Milos Island, Greece. The above pozzolana samples, which were ground in the laboratory ball mill for cement production performed differently during grinding and that was reflected upon the specific surface area (cm2/gr) values. The perlites and the glassy tuff were the hardest to grind, whereas, the zeolite tuff and the Australian diatomite were the easiest ones. However, the exceedingly high specific surface area of the Australian diatomite renders cement difficult to transport and tricky to use for concrete manufacturing, due to the high water demand of the cement mixture. Regarding

  15. Effect of the sterilization process on physical and mechanical properties of the bonacryl bone cement

    International Nuclear Information System (INIS)

    The use of bone cements of poly(methyl methacrylate) (PMMA) to fix artificial prosthesis to the human body is a habitual method in orthopedic surgery. The hip and the knee joints have a very complex biomechanics and support high loads, for these reasons, acrylic bone cements have to comply with international standards in order to secure the biofuncionality and durability of the implant. In this work we report the effect of sterilization by ethylene oxide or gamma radiation on the BONACRYL Cuban cement. We determined how sterilization methods affect the molecular weight of the polymer as well as its quasi-static mechanical properties. The results demonstrated that the gamma radiation modifies the molecular weight of the PMMA although the compression and bending strength were not affected by the sterilization process applied. (authors)

  16. Effects of adding resorbable chitosan microspheres to calcium phosphate cements for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Dan [Department of Prosthodontics, Beijing Stomatological Hospital, Capital Medical University, Beijing 100050 (China); Dong, Limin [Beijing Key Lab of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Energy Science Building, Beijing 100084 (China); Wen, Ying [Department of Prosthodontics, Beijing Stomatological Hospital, Capital Medical University, Beijing 100050 (China); Xie, Qiufei, E-mail: xieqiuf@163.com [Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081 (China)

    2015-02-01

    Calcium phosphate cements (CPCs) have been widely used as bone graft substitutes. However, the undesirable osteoinductivity and slow degradability of CPCs greatly hamper their clinical application. The aim of this study was to synthesize a type of injectable, bioactive cement. This was accomplished by incorporating chitosan microspheres into CPC. CPC containing chitosan microspheres was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). XRD showed that the hardened chitosan microsphere/CPC with different proportions of microspheres contained diffraction peaks of hydroxyapatite and chitosan. Compressive strength and dissolution in simulated body fluid were measured. The chitosan microsphere/CPC containing 10% (w/w) chitosan microspheres had a compressive strength of 14.78 ± 0.67 MPa. Cavity defects were created in both femoral condylar regions of New Zealand White rabbits. Chitosan microsphere/CPC (composite group) and α-TCP/CPC (control group) were implanted separately into the bone defects of both femurs. X-ray analysis was performed to observe the filling of these bone defects 3 days after surgery. The extent of bone substitute degradation and new bone formation were evaluated by SEM and histological examination at 8, 16, and 24 weeks after implantation. These results showed far more new bone formation and degradation of the chitosan microsphere/CPC composite in the bone defects. These data indicate that a chitosan microsphere/CPC composite might be considered as a promising injectable material for the generation of new bone tissue. - Highlights: • We synthesized an injectable, bioactive chitosan microsphere/CPC for the first time. • 100–400 μm chitosan microspheres were incorporated into the cement solid phase. • XRD showed the construct contained diffraction peaks of hydroxyapatite and chitosan. • Compressive strength of the composite was about 15 MPa comparable to cancellous bone. • The new construct shows better bone

  17. Effects of adding resorbable chitosan microspheres to calcium phosphate cements for bone regeneration

    International Nuclear Information System (INIS)

    Calcium phosphate cements (CPCs) have been widely used as bone graft substitutes. However, the undesirable osteoinductivity and slow degradability of CPCs greatly hamper their clinical application. The aim of this study was to synthesize a type of injectable, bioactive cement. This was accomplished by incorporating chitosan microspheres into CPC. CPC containing chitosan microspheres was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). XRD showed that the hardened chitosan microsphere/CPC with different proportions of microspheres contained diffraction peaks of hydroxyapatite and chitosan. Compressive strength and dissolution in simulated body fluid were measured. The chitosan microsphere/CPC containing 10% (w/w) chitosan microspheres had a compressive strength of 14.78 ± 0.67 MPa. Cavity defects were created in both femoral condylar regions of New Zealand White rabbits. Chitosan microsphere/CPC (composite group) and α-TCP/CPC (control group) were implanted separately into the bone defects of both femurs. X-ray analysis was performed to observe the filling of these bone defects 3 days after surgery. The extent of bone substitute degradation and new bone formation were evaluated by SEM and histological examination at 8, 16, and 24 weeks after implantation. These results showed far more new bone formation and degradation of the chitosan microsphere/CPC composite in the bone defects. These data indicate that a chitosan microsphere/CPC composite might be considered as a promising injectable material for the generation of new bone tissue. - Highlights: • We synthesized an injectable, bioactive chitosan microsphere/CPC for the first time. • 100–400 μm chitosan microspheres were incorporated into the cement solid phase. • XRD showed the construct contained diffraction peaks of hydroxyapatite and chitosan. • Compressive strength of the composite was about 15 MPa comparable to cancellous bone. • The new construct shows better bone

  18. Immunological aspects related to the biomaterials used in bone additions

    OpenAIRE

    Papakoca, Kiro; Neamtu, Raluca; Drafta, Sergiu; Dimitriu, Bogdan; Mihai, Augustin; Durbaca, Ioana

    2010-01-01

    In the last two decades, biomaterials have become of great importance for medical practice. thus, biomatrials used for bone addition or bone augmentation are used not only in orthopedics or traumatology, but also in dental medicine, especially in oral implantology to repair some bone defects small or vast in scope.

  19. Asymptomatic Bone Cement Pulmonary Embolism after Vertebroplasty: Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Girolamo Geraci

    2013-01-01

    Full Text Available Introduction. Acrylic cement pulmonary embolism is a potentially serious complication following vertebroplasty. Case Report. A 70-year-old male patient was treated with percutaneous vertebroplasty for osteoporotic nontraumatic vertebral collapse of L5-S1. Asymptomatic pulmonary cement embolism was detected on routine postoperative chest radiogram and the patient was treated with enoxaparin, amoxicillin, and dexamethasone. At the followup CT scan no further migration of any cement material was reported; and the course was uneventful. Discussion. The frequency of local leakage of bone cement is relatively high (about 80–90%, moreover, the rate of cement leakage into the perivertebral veins (seen in up to 24% of vertebral bodies treated with consequent pulmonary cement embolism varies from 4.6 to 6.8% (up to 26% in radiologic studies; the risk of embolism is increased with the liquid consistency of the cement and with the treatment of some malignant lesions. Patients may remain asymptomatic and develop no known long-term sequelae. Conclusions. Our ancedotal case illustrates the need for close monitoring of patients undergoing percutaneous vertebroplasty and emphasizes the importance of prompt and correct diagnosis and treatment, even if actually there is no agreement regarding the therapeutic strategy.

  20. Enhanced healing of rabbit segmental radius defects with surface-coated calcium phosphate cement/bone morphogenetic protein-2 scaffolds

    International Nuclear Information System (INIS)

    Large osseous defects remain a difficult clinical problem in orthopedic surgery owing to the limited effective therapeutic options, and bone morphogenetic protein-2 (BMP-2) is useful for its potent osteoinductive properties in bone regeneration. Here we build a strategy to achieve prolonged duration time and help inducting new bone formation by using water-soluble polymers as a protective film. In this study, calcium phosphate cement (CPC) scaffolds were prepared as the matrix and combined with sodium carboxymethyl cellulose (CMC-Na), hydroxypropylmethyl cellulose (HPMC), and polyvinyl alcohol (PVA) respectively to protect from the digestion of rhBMP-2. After being implanted in the mouse thigh muscles, the surface-modified composite scaffolds evidently induced ectopic bone formation. In addition, we further evaluated the in vivo effects of surface-modified scaffolds in a rabbit radius critical defect by radiography, three dimensional micro-computed tomographic (μCT) imaging, synchrotron radiation-based micro-computed tomographic (SRμCT) imaging, histological analysis, and biomechanical measurement. The HPMC-modified CPC scaffold was regarded as the best combination for segmental bone regeneration in rabbit radius. - Highlights: • A simple surface-coating method was used to fabricate composite scaffolds. • Growth factor was protected from rapid depletion via superficial coating. • Significant promotion of bone regeneration was achieved. • HPMC-modification displayed optimal effect of bone regeneration

  1. Enhanced healing of rabbit segmental radius defects with surface-coated calcium phosphate cement/bone morphogenetic protein-2 scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yi; Hou, Juan; Yin, ManLi [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Wang, Jing, E-mail: biomatwj@163.com [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Liu, ChangSheng, E-mail: csliu@sh163.net [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China)

    2014-11-01

    Large osseous defects remain a difficult clinical problem in orthopedic surgery owing to the limited effective therapeutic options, and bone morphogenetic protein-2 (BMP-2) is useful for its potent osteoinductive properties in bone regeneration. Here we build a strategy to achieve prolonged duration time and help inducting new bone formation by using water-soluble polymers as a protective film. In this study, calcium phosphate cement (CPC) scaffolds were prepared as the matrix and combined with sodium carboxymethyl cellulose (CMC-Na), hydroxypropylmethyl cellulose (HPMC), and polyvinyl alcohol (PVA) respectively to protect from the digestion of rhBMP-2. After being implanted in the mouse thigh muscles, the surface-modified composite scaffolds evidently induced ectopic bone formation. In addition, we further evaluated the in vivo effects of surface-modified scaffolds in a rabbit radius critical defect by radiography, three dimensional micro-computed tomographic (μCT) imaging, synchrotron radiation-based micro-computed tomographic (SRμCT) imaging, histological analysis, and biomechanical measurement. The HPMC-modified CPC scaffold was regarded as the best combination for segmental bone regeneration in rabbit radius. - Highlights: • A simple surface-coating method was used to fabricate composite scaffolds. • Growth factor was protected from rapid depletion via superficial coating. • Significant promotion of bone regeneration was achieved. • HPMC-modification displayed optimal effect of bone regeneration.

  2. Concrete Durability Properties and Microstructural Analysis of Cement Pastes with Nopal Cactus Mucilage as a Natural Additive

    OpenAIRE

    Ramírez-Arellanes, S.; Cano-Barrita, P. F. de J.; Julián-Caballero, F.; Gómez-Yañez, C.

    2012-01-01

    The present study evaluated the addition of a 3% nopal cactus mucilage solution to cement pastes, in its effects on setting times, flow, hydration, and microstructure, as well as on capillary water absorption and chloride diffusion in concrete. Hydration was characterized through XRD and microstructure was characterized with SEM. The mucilage solution/cement and water/cement ratios tested were 0.30, 0.45, and 0.60. The results in cement pastes indicate that the addition of mucilage increases ...

  3. Modifications on the properties of a calcium phosphate cement by additions of sodium alginate

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, W.T.; Fernandes, J.M.; Vieira, R.S.; Thurmer, M.B.; Santos, L.A., E-mail: trajano@ufrgs.br, E-mail: julianafernandes2@yahoo.com.br, E-mail: rsvieira.eng@gmail.com, E-mail: monicathurmer@yahoo.com.br, E-mail: luis.santos@ufrgs.br [Universidade Federal do Rio Grande do Sul (PPG/LABIOMAT/UFRGS), RS (Brazil)

    2012-07-01

    The Calcium Phosphate Cement (CPC) are bone substitutes with great potential for use in orthopedics, traumatology and dentistry due to its biocompatibility, bioactivity and osteoconductivity, and form a paste that can be easily shaped and placed into the surgical site. However, CPCs have low mechanical strength, which equals the maximum mechanical strength of trabecular bone. In order to assess the strength and time to handle a CPC composed primarily of alpha phase, were added sodium alginate (1%, 2% and 3% wt) and an accelerator in an aqueous solution. The cement powder was mixed with liquid of setting, shaped into specimens and evaluated for apparent density and porosity by Archimedes method, X-ray diffraction and compressive strength. A significant increase in compressive strength by adding sodium alginate was verified. (author)

  4. Modifications on the properties of a calcium phosphate cement by additions of sodium alginate

    International Nuclear Information System (INIS)

    The Calcium Phosphate Cement (CPC) are bone substitutes with great potential for use in orthopedics, traumatology and dentistry due to its biocompatibility, bioactivity and osteoconductivity, and form a paste that can be easily shaped and placed into the surgical site. However, CPCs have low mechanical strength, which equals the maximum mechanical strength of trabecular bone. In order to assess the strength and time to handle a CPC composed primarily of alpha phase, were added sodium alginate (1%, 2% and 3% wt) and an accelerator in an aqueous solution. The cement powder was mixed with liquid of setting, shaped into specimens and evaluated for apparent density and porosity by Archimedes method, X-ray diffraction and compressive strength. A significant increase in compressive strength by adding sodium alginate was verified. (author)

  5. Effect of the addition of nanosilica on white cement hydration at 25°C

    OpenAIRE

    Sáez del Bosque I.F.; Martínez-Ramírez S.; Martín-Pastor M.; Teresa Blanco-Varela M.

    2014-01-01

    The cement industry is keen on reducing natural resource consumption, reusing waste that would otherwise be sent to a rubbish tip and lowering its CO2 emissions. In pursuit of those objectives, the addition of materials such as silica fume, ceramic waste, rice husk and precipitated or colloidal nanosilica, in the various stages of cement manufacture has become increasingly common. That practice inspired the present study (using isothermal conduction calorimetry, 29Si and 27Al MAS NMR, XRD and...

  6. Effect of nanosilica addition on White cement hydration at 25ºC.

    OpenAIRE

    Sáez del Bosque, I. F.; Martínez Ramírez, Sagrario; Martín-Pastor, Manuel; Blanco-Varela, María Teresa

    2013-01-01

    The cement industry is keen on reducing natural resource consumption, reusing waste that would otherwise be sent to a rubbish tip and lowering its CO2 emissions. In pursuit of those objectives, the addition of materials such as silica fume, ceramic waste, rice husk and precipitated or colloidal nanosilica, in the various stages of cement manufacture has become increasingly common. That practice inspired the present study (using isothermal conduction calorimetry, 29Si and 27Al MAS NMR, XRD and...

  7. Utilization of municipal sewage sludge as additives for the production of eco-cement

    International Nuclear Information System (INIS)

    Highlights: ► The results of X-ray diffraction (XRD) pattern and scanning electron micrograph (SEM) indicated that the major components in the eco-cement clinkers were similar to those in ordinary Portland cement. ► Though the C2S phase formation increased with the increase of sewage sludge contents. ► All the eco-cement pastes had a longer initial setting time and final setting time than those of plain cement paste, which increased as the sewage sludge contents in raw meal increased. ► All the eco-cement pastes had lower early flexural strengths and it increased with the increase of sewage sludge contents increased, while the compressive strengths decreased slightly. ► However, it had no significant effect on all the strengths at later ages. - Abstract: The effects of using dried sewage sludge as additive on cement property in the process of clinker burning were investigated in this paper. The eco-cement samples were prepared by adding 0.50–15.0% of dried sewage sludge to unit raw meal, and then the mixtures were burned at 1450 °C for 2 h. The results indicated that the major components in the eco-cement clinkers were similar to those in ordinary Portland cement. Although the C2S phase formation increased with the increase of sewage sludge content, it was also found that the microstructure of the mixture containing 15.0% sewage sludge in raw meal was significantly different and that a larger amount of pores were distributed in the clinker. Moreover, all the eco-cement pastes had a longer initial setting time and final setting time than those of plain cement paste, which increased as the sewage sludge content in the raw meal increased. All the eco-cement pastes had lower early flexural strengths, which increased as the sewage sludge content increased, while the compressive strengths decreased slightly. However, this had no significant effect on all the strengths at later stages. Furthermore, the leaching concentrations of all the types of eco-cement

  8. Synthesis and characterization of cement slurries additives with epoxy resins - kinetics, thermodynamic and calorimetric analysis

    International Nuclear Information System (INIS)

    Cement has been used in the world, presenting a wide versatility. However, due to its chemical nature, it is subject to several types of chemical damages, especially for agents of acidic nature. With the purpose of increase its life-time, new cement slurries have been modified with the addition of specific additives. The objective of this work is to modify cement slurries with epoxy resins, which promote higher resistance of those materials in relation to acid attacks. Three cement slurries were synthesized with epoxy resins and a standard slurries, which was composed by cement and water. After 30 days of hydration, the samples were characterized by XDR, FTIR and thermal analysis (TG and DSC). The hydration processes of the cement slurries were studied by heat-conduction microcalorimetry. A kinetic study of HCl interaction with the new slurries were performed by the batch methodology at 25, 35, 45 e 55 deg C. It was verified that the addition of the polymers delayed the processes of hydration of the slurries, decreasing the flow of heat released as a function of the amount of added resin and, increased the resistance of those slurries to the acid attack. (author)

  9. Strontium-loaded mineral bone cements as sustained release systems : Compositions, release properties, and effects on human osteoprogenitor cells

    OpenAIRE

    Tadier, Solène; Bareille, Reine; Siadous, Robin; Marsan, Olivier; Charvillat, Cédric; Cazalbou, Sophie; Amédée, Joelle; Rey, Christian; Combes, Christèle

    2012-01-01

    This study aims to evaluate in vitro the release properties and biological behavior of original compositions of strontium (Sr)-loaded bone mineral cements. Strontium was introduced into vaterite CaCO3-dicalcium phosphate dihydrate cement via two routes: as SrCO3 in the solid phase (SrS cements), and as SrCl2 dissolved in the liquid phase (SrL cements), leading to different cement compositions after setting. Complementary analytical techniques implemented to thoroughly investigate the re...

  10. The influence of additives on leaching of tritium of the immobilization matrices of contaminated oils by cementation

    International Nuclear Information System (INIS)

    The research studies showed that the solidification of contaminated pump oils resulted from Cernavoda NPP operation can be done by using various immobilization matrices such as: cement with appropriate mineral additives sand of Aghires, lime and silicate accelerator. Research works and experiments were carried out on four groups: cement-emulsion, cement-emulsion-silicate accelerator, cement-emulsion-lime- silicate accelerator and cement-emulsion-sand of Aghires. The paper presents the author's research on immobilization of contaminated oil by cementation using Romanian emulsifiers. With both of the emulsifiers used, there were obtained reasonable compressive strengths and leaching rates. (author)

  11. Improvement of in vitro physicochemical properties and osteogenic activity of calcium sulfate cement for bone repair by dicalcium silicate

    International Nuclear Information System (INIS)

    Highlights: • Dicalcium silicate can improve osteogenic activity of calcium sulfate cement. • The higher the calcium sulfate content, the shorter the setting time in the composite cement. • The results were useful for designing calcium-based cement with optimal properties. -- Abstract: An ideal bone graft substitute should have the same speed of degradation as formation of new bone tissue. To improve the properties of calcium sulfate hemihydrate (CSH) featured for its rapid resorption, a low degradation material of dicalcium silicate (DCS) was added to the CSH cement. This study examined the effect of DCS (20, 40, 60 and 80 wt%) on the in vitro physicochemical properties and osteogenic activities of the calcium-based composite cements. The diametral tensile strength, porosity and weight loss of the composite cements were evaluated before and after soaking in a simulated body fluid (SBF). The osteogenic activities, such as proliferation, differentiation and mineralization, of human mesenchymal stem cells (hMSCs) seeded on cement surfaces were also examined. As a result, the greater the DCS amount, the higher the setting time was in the cement. Before soaking in SBF, the diametral tensile strength of the composite cements was decreased due to the introduction of DCS. On 180-day soaking, the composite cements containing 20, 40, 60 and 80 wt% DCS lost 80%, 69%, 61% and 44% in strength, respectively. Regarding in vitro bioactivity, the DCS-rich cements were covered with clusters of apatite spherulites after soaking for 7 days, while there was no formation of apatite spherulites on the CSH-rich cement surfaces. The presence of DCS could reduce the degradation of the CSH cements, as evidenced in the results of weight loss and porosity. More importantly, DCS may promote effectively the cell proliferation, proliferation and mineralization. The combination of osteogenesis of DCS and degradation of CSH made the calcium-based composite cements an attractive choice for

  12. Material properties and in vitro biocompatibility of a newly developed bone cement

    OpenAIRE

    Elke Mitzner; Paco Albertus Hubert Maria Pelt; Christian Mueller; Angela Strohwig; Wolf-Dieter Mueller

    2009-01-01

    In this study mechanical properties and biocompatibility (In Vitro) of a new bone cement were investigated. A new platform technology named COOL is a variable composite of dissolved, chemically modified PMMA and different bioceramics. COOL cures at body temperature via a classical cementation reaction. Compressive strengths ranging from 3.6 ± 0.8 to 62.8 ± 1.3 MPa and bending strengths ranging from 9.9 ± 2.4 to 26.4 ± 3.0 MPa were achieved with different COOL formulations. Porosity varied bet...

  13. Fixation of a human rib by an intramedullary telescoping splint anchored by bone cement.

    Science.gov (United States)

    Liovic, Petar; Šutalo, Ilija D; Marasco, Silvana F

    2016-09-01

    A novel concept for rib fixation is presented that involves the use of a bioresorbable polymer intramedullary telescoping splint. Bone cement is used to anchor each end of the splint inside the medullary canal on each side of the fracture site. In this manner, rib fixation is achieved without fixation device protrusion from the rib, making the splint completely intramedullary. Finite element analysis is used to demonstrate that such a splint/cement composite can preserve rib fixation subjected to cough-intensity force loadings. Computational fluid dynamics and porcine rib experiments were used to study the anchor formation process required to complete the fixation. PMID:26733094

  14. The influence of ultrasound on the release of gentamicin from antibiotic-loaded acrylic beads and bone cements

    NARCIS (Netherlands)

    Ensing, GT; Hendriks, JGE; Jongsma, JE; van Horn, [No Value; van der Mei, HC; Busscher, HJ

    2005-01-01

    Gentamicin-loaded acrylic beads are loosely placed in infected bone cavities, whereas gentamicin-loaded acrylic bone cement is used as a mechanical filler in bone to anchor prosthetic components. Both drug delivery systems are used to decrease infection rates by gentamicin release. The objective of

  15. Influence of liquid phase on physical properties of the new triphasic bone cement

    Directory of Open Access Journals (Sweden)

    A. Ślósarczyk

    2012-04-01

    Full Text Available Purpose: The aim of this work was to develop a new bone cement based on hydroxyapatite (HAp, βTCP and calcium sulfate hemihydrate (CSH and to determine the influence of a liquid phase, used for cement pastes preparation, on physical properties of the final implant material.Design/methodology/approach: The powder phase consisting of CSH (60 wt.% and HAp+ βTCP (40 wt.% was applied. Composite samples were prepared using distilled water, chitosan and methylcellulose solutions as the liquid phases. Rheological properties of the solutions were measured by Brookfield rheometer. Initial and final setting times of the cement pastes were determined. Phase composition of hardened bodies was established using XRD method. Microstructure was investigated by SEM while pore size distribution by mercury porosimetry. Compressive strength was measured by Instron Universal Testing Machine.Findings: According to the conducted rheological measurements of the methylcellulose and chitosan solutions as well as evaluated cement pastes and hardened bodies properties, the optimal setting liquids were chosen.Research limitations/implications: The evaluation of a biological response to the developed materials, including in vitro and in vivo experiments, need to be done.Practical implications: The possibility of creation the physical properties of setting in vivo composites, designed for filling bone defects, via establishing the suitable liquid phase was confirmed.Originality/value: The new composite type triphasic bone substitute, based on CSH, HAp and βTCP, with superior resorbability in comparison to the commercially available calcium phosphate bone cements was developed. The influence of liquid phase on the microstructure and mechanical strength of this implant material was determined.

  16. Hydration of alumina cement containing ferrotitanium slag with polycarboxylate-ethers (PCE) additives

    Science.gov (United States)

    Rechkalov, Denis; Chernogorlov, Sergey; Abyzov, Victor

    2016-01-01

    The paper is discussing results of study of alumina binder containing aluminous cement and ferrotitanium slag from aluminothermic process by Kliuchevskoi Ferroalloys corp. with various additives containing polycarboxylate-ethers (PCE). Selecting ferrotitanium slag as additive is based on the fact that its content of alumina and phase composition is closest to the alumina cement. The composition of the ferrotitanium slag is displayed. In order to compensate the decrease in strength caused by addition of ferrotitanium slag having low activity, PCE additives were added. As PCE additives were used Melflux 1641F, Melflux 2651F and Melflux PP200F by BASF. The effect of additives on the hydration of the binder, depending on the amount and time of additives hardening is shown. The composition of the hydration products in the cement was studied by physico-chemical analysis: derivatography and X-ray analysis. It is found that in the early stages of hardening PCE additives have inhibitory effect on hydration processes and promote new phase amorphization. The optimal content of additives was investigated. The basic properties of the binders have been tested. It was observed that the modified binders meet the requirements of Russian National State Standard GOST 969 to the alumina cement.

  17. Vacuum Sealing Drainage Treatment Combined with Antibiotic-Impregnated Bone Cement for Treatment of Soft Tissue Defects and Infection

    Science.gov (United States)

    Liu, Xin; Liang, Jiulong; Zhao, Jun; Quan, Liangliang; Jia, Xunyuan; Li, Mingchao; Tao, Kai

    2016-01-01

    Background This study aimed to evaluate the combined effect of vacuum sealing drainage (VSD) and antibiotic-loaded bone cement on soft tissue defects and infection. Material/Methods This prospective non-blinded study recruited 46 patients with soft tissue defects and infection from January 2010 to May 2014 and randomly divided them into experimental and control groups (n=23). Patients in the experimental group were treated with VSD and antibiotic-loaded bone cement, while the patients in the control group were treated with VSD only. Results In the experimental group, the wound was healed in 23 cases at 4 weeks postoperatively, of which direct suture was performed in 12 cases, and additional free flap transplantation or skin grafting was performed in 6 cases and 5 cases, respectively. No infection reoccurred in 1-year follow-up. In the control group, the wound was healed in 15 cases at 6 weeks postoperatively, of which direct suture was performed in 8 cases, and additional free flap transplantation or skin grafting was performed in 3 cases and 4 cases, respectively. In the other 8 cases the wound was healed at 8 weeks postoperatively. Infection reoccurred in 3 cases during the follow-up. The experimental group had significantly fewer VSD dressing renewals, shorter time needed until the wound was ready for surgery, shorter duration of antibiotic administration, faster wound healing, and shorter hospital stay than the control group (p<0.01). Conclusions The combination of VSD and antibiotic bone cement might be a better method for treatment of soft tissue defects and infection. PMID:27281233

  18. The progress of early phase bone healing using porous granules produced from calcium phosphate cement

    Directory of Open Access Journals (Sweden)

    Jungbluth P

    2010-05-01

    Full Text Available Abstract Objective Bone grafting is a vital component in many surgical procedures to facilitate the repair of bone defects or fusions. Autologous bone has been the gold standard to date in spite of associated donor-site morbidity and the limited amount of available donor bone. The aim of this study was to investigate the progress of bone regeneration and material degradation of calcium phosphate granules (CPG produced from a calcium phosphate self-setting cement powder compared to the use of autologous bone grafting in the treatment of "critical size defects" on load-bearing long bones of minipigs. Methods A critical size defect in the tibial metaphysis of 16 mini-pigs was filled either with autologous cancellous graft or with micro- and macroporous carbonated, apatic calcium phosphate granules (CPG produced from a calcium phosphate self-setting cement powder. After 6 weeks, the specimens were assessed by X-ray and histological evaluation. The amount of new bone formation was analysed histomorphometrically. Results The semi-quantitative analysis of the radiological results showed a complete osseous bridging of the defect in three cases for the autograft group. In the same group five animals showed a beginning, but still incomplete bridging of the defect, whereas in the CPG group just two animals developed this. All other animals of the CPG group showed only a still discontinuous new bone formation. Altogether, radiologically a better osseous bridging was observed in the autograft group compared to the CPG group. Histomorphometrical analysis after six weeks of healing revealed that the area of new bone was significantly greater in the autograft group concerning the central area of the defect zone (p Conclusions Within the limits of the present study it could be demonstrated that autologous cancellous grafts lead to a significantly better bone regeneration compared to the application of calcium phosphate granules (CPG produced from a calcium

  19. Augmentation of femoral neck fracture fixation with an injectable calcium-phosphate bone mineral cement.

    Science.gov (United States)

    Stankewich, C J; Swiontkowski, M F; Tencer, A F; Yetkinler, D N; Poser, R D

    1996-09-01

    The first goal of this study was to determine if augmentation with an injectable, in situ setting, calcium-phosphate cement that is capable of being remodeled and was designed to mimic bone mineral significantly improved the strength and stiffness of fixation in a cadaveric femoral neck fracture model. The second goal was to determine if greater increases in fixation strength were achieved as the bone density of the specimen decreased. Sixteen pairs of fresh cadaveric human femora with a mean age of 70.9 years (SD = 17.2 years) were utilized. The bone density of the femoral neck was measured with dual-energy x-ray absorptiometry. The femoral head was impacted vertically with the femoral shaft fixed in 12 degrees of adduction using a materials testing machine to create a fully displaced fracture. Following fracture, 30% inferior comminution was created in each specimen. One randomly chosen femur from each pair underwent anatomic reduction and fixation with three cannulated cancellous bone screws, 7 mm in diameter, in an inverted triangle configuration. The contralateral femur underwent the same fixation augmented with calcium-phosphate cement. Specimens were preconditioned followed by 1.000 cycles to one body weight (611.6 N) at 0.5 Hz to simulate single-limb stance loading. The stiffness in the first cycle was observed to be significantly greater in cement-augmented specimens compared with unaugmented controls (p bone mineral cement failed at a mean of 4,573 N (SD = 1,243 N); this was significantly greater (p bone density (p = 0.25, R2 = 0.09), was weakly correlated to the volume of cement injected (p = 0.07, R2 = 0.22), and was inversely related to the fixation failure load of the control specimen (p = 0.001, R2 = 0.54). There was a mean relative improvement in fixation strength of 169.6% (SD = 77.5). These findings suggest that calcium-phosphate cement provides initial beneficial augmentation to fixation of femoral neck fractures. PMID:8893773

  20. Effects of Incorporating Carboxymethyl Chitosan into PMMA Bone Cement Containing Methotrexate.

    Directory of Open Access Journals (Sweden)

    Bo-Ming Liu

    Full Text Available Treatment of bone metastases usually includes surgical resection with local filling of methotrexate (MTX in polymethyl methacrylate (PMMA cement. We investigated whether incorporating carboxymethyl chitosan (CMCS in MTX-PMMA cement might overcome disadvantages associated with MTX. To determine the optimal CMCS+MTX concentration to suppress the viability of cancer cells, an integrated microfluidic chip culturing highly metastatic lung cancer cells (H460 was employed. The mechanical properties, microstructure, and MTX release of (CMCS+MTX-PMMA cement were evaluated respectively by universal mechanical testing machine, scanning electron microscopy (SEM, and incubation in simulated body fluid with subsequent HPLC-MS. Implants of MTX-PMMA and (CMCS+MTX-PMMA cement were evaluated in vivo in guinea pig femurs over time using spiral computed tomography with three-dimensional image reconstruction, and SEM at 6 months. Viability of H460 cells was significantly lowest after treatment with 57 μg/mL CMCS + 21 μg/mL MTX, which was thus used in subsequent experiments. Incorporation of 1.6% (w/w CMCS to MTX-PMMA significantly increased the bending modulus, bending strength, and compressive strength by 5, 2.8, and 5.2%, respectively, confirmed by improved microstructural homogeneity. Incorporation of CMCS delayed the time-to-plateau of MTX release by 2 days, but increased the fraction released at the plateau from 3.24% (MTX-PMMA to 5.34%. Relative to the controls, the (CMCS+MTX-PMMA implants integrated better with the host bone. SEM revealed pores in the cement of the (CMCS+MTX-PMMA implants that were not obvious in the controls. In conclusion, incorporation of CMCS in MTX-PMMA appears a feasible and effective modification for improving the anti-tumor properties of MTX-PMMA cement.

  1. Damage accumulation, fatigue and creep behaviour of vacuum mixed bone cement.

    Science.gov (United States)

    Jeffers, Jonathan R T; Browne, Martin; Taylor, Mark

    2005-09-01

    The behaviour of bone cement under fatigue loading is of interest to assess the long-term in vivo performance. In this study, uniaxial tensile fatigue tests were performed on CMW-1 bone cement. Acoustic emission sensors and an extensometer were attached to monitor damage accumulation and creep deformation respectively. The S-N data exhibited the scatter synonymous with bone cement fatigue, with large pores generally responsible for premature failure; at 20 MPa specimens failed between 2 x 10(3) and 2 x 10(4) load cycles, while at 7 MPa specimens failed from 3 x 10(5) load cycles but others were still intact after 3 x 10(6) load cycles. Acoustic emission data revealed a non-linear accumulation of damage with respect to time, with increasing non-linearity at higher stress levels. The damage accumulation process was not continuous, but occurred in bursts separated by periods of inactivity. Damage in the specimen was located by acoustic emissions, and allowed the failure site to be predicted. Acoustic emission data were also used to predict when failure was not imminent. When this was the case at 3 million load cycles, the tests were terminated. Creep strain was plotted against the number of load cycles and a linear relationship was found when a double logarithmic scale was employed. This is the first time a brand of cement has been characterised in such detail, i.e. fatigue life, creep and damage accumulation. Results are presented in a manner that allows direct comparison with published data for other cements. The data can also be used to characterise CMW-1 in computational simulations of the damage accumulation process. Further evidence is provided for the condition-monitoring capabilities of the acoustic emission technique in orthopaedic applications. PMID:15860209

  2. Bond strength analysis of the bone cement- stem interface of hip arthroplasties

    Institute of Scientific and Technical Information of China (English)

    Lan-Feng Zhang; Shi-Rong Ge; Hong-Tao Liu; Kai-Jin Guo; Shu-Yang Han; Juan-Yan Qi

    2014-01-01

    Objective:To study and establish the preliminary linear and modified models for the interface shear mechanics performance between implant and bone cement and to explore its damage significance.Method:The loosening research between artificial hip joint prosthesis stem and bone cement interface performance can be evaluated by the push-in test.Based on the debonding performance test, the analytical expressions of the average load and displacement from the debonding failure and splitting failure process were deduced and determined.The correlations of the expressions of the average load-displacement and statistical experimental data were analyzed.Results:It demonstrated that the interface debonding failure mechanical model could be characterized as interface bond strength mechanical performance.Based on analysis of models and experimental data by the three statistical analysis methods, the results indicated the modified model could be better represented by the interfacial debonding strength properties. The bond stressτand relative slidings distribution along the embedment regional were coupling affected by both pressure arch effect and shear lag effect in bone cement.Two stress peaks of implant have been found at the distance from0.175La loading tip to0.325Lafree tip, which also verified the early loosening clinical reports for the proximal and latter region.As the bone cement arch effect, the bond stress peak tend to move to the free tip when the debonding failure would be changed into the splitting failure, which presents a preliminary study on the mechanism of early debonding failurefor the stem-cement interface.Conclusions:Functional models of the stem-bone cement interfacial debonding failure are developed to analyze the relevant mechanism.The different locational titanium alloy stress, and the interfacial bond stress and the relative slides are evaluated to acquire a guide of the different positions of interfacial damage.The coupling effect which is original from

  3. Evaluation of a radiation transport modeling method for radioactive bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, T S [Department of Radiological Sciences, B170 Med Sci I, University of California, Irvine, CA 92697 (United States); Sehgal, V; Al-Ghazi, M S A L; Ramisinghani, N S [Department of Radiation Oncology, University of California Irvine Medical Center, Orange, CA 92868 (United States); Skinner, H B [St Jude Heritage Medical Group, Fullerton, CA 92835 (United States); Keyak, J H [Departments of Radiological Sciences, Biomedical Engineering, and Mechanical Engineering, University of California, Irvine, CA 92697 (United States)], E-mail: tkaneko@uci.edu

    2010-05-07

    Spinal metastases are a common and serious manifestation of cancer, and are often treated with vertebroplasty/kyphoplasty followed by external beam radiation therapy (EBRT). As an alternative, we have introduced radioactive bone cement, i.e. bone cement incorporated with a radionuclide. In this study, we present a Monte Carlo radiation transport modeling method to calculate dose distributions within vertebrae containing radioactive cement. Model accuracy was evaluated by comparing model-predicted depth-dose curves to those measured experimentally in eight cadaveric vertebrae using radiochromic film. The high-gradient regions of the depth-dose curves differed by radial distances of 0.3-0.9 mm, an improvement over EBRT dosimetry accuracy. The low-gradient regions differed by 0.033-0.055 Gy/h/mCi, which may be important in situations involving prior spinal cord irradiation. Using a more rigorous evaluation of model accuracy, four models predicted the measured dose distribution within the experimental uncertainty, as represented by the 95% confidence interval of the measured log-linear depth-dose curve. The remaining four models required modification to account for marrow lost from the vertebrae during specimen preparation. However, the accuracy of the modified model results indicated that, when this source of uncertainty is accounted for, this modeling method can be used to predict dose distributions in vertebrae containing radioactive cement.

  4. Antibacterial and bioactive composite bone cements containing surface silver-doped glass particles.

    Science.gov (United States)

    Miola, Marta; Fucale, Giacomo; Maina, Giovanni; Verné, Enrica

    2015-09-01

    A bioactive silica-based glass powder (SBA2) was doped with silver (Ag(+)) ions by means of an ion-exchange process. Scanning electron microscopy (SEM), energy dispersion spectrometry (EDS) and x-ray diffraction (XRD) evidenced that the glass powder was enriched with Ag(+) ions. However, a small amount of Ag2CO3 precipitated with increased Ag concentrations in the exchange solution. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of Ag-SBA2 towards Staphylococcus aureus were also evaluated and were respectively 0.05 mg ml(-1) and 0.2 mg ml(-1). Subsequently, Ag-SBA2 glass was used as filler (30%wt) in a commercial formulation of bone cement (Simplex(™) P) in order to impart both antibacterial and bioactive properties. The composite bone cement was investigated in terms of morphology (using SEM) and composition (using EDS); the glass powder was well dispersed and exposed on the cement surface. Bioactivity tests in simulated body fluid (SBF) evidenced the precipitation of hydroxyapatite on sample surfaces. Composite cement demonstrated antibacterial properties and a compressive strength comparable to the commercial formulation. PMID:26481324

  5. Improvement of cement concrete strength properties by carbon fiber additives

    Science.gov (United States)

    Nevsky, Andrey; Kudyakov, Konstantin; Danke, Ilia; Kudyakov, Aleksandr; Kudyakov, Vitaly

    2016-01-01

    The paper presents the results of studies of fiber-reinforced concrete with carbon fibers. The effectiveness of carbon fibers uniform distribution in the concrete was obtained as a result of its preliminary mechanical mixing in water solution with chemical additives. Additives are to be used in the concrete technology as modifiers at initial stage of concrete mix preparing. The technology of preparing of fiber-reinforced concrete mix with carbon fibers is developed. The superplasticizer is based on ether carboxylates as a separator for carbon fibers. The technology allows increasing of concrete compressive strength up to 43.4% and tensile strength up to 17.5% as well as improving stability of mechanical properties.

  6. Study of chemical additives in the cementation of radioactive waste of PWR reactors

    International Nuclear Information System (INIS)

    In this research it has been studied the effects of chemical admixtures in the cementation process of radioactive wastes. These additives are used to improve the properties of waste cementation process, both of the paste and of the solidified product. However there are a large variety of these materials that are frequently changed or taken out of the market. Then it is essential to know the commercially available materials and their effects. The tests were carried out with a solution simulating the evaporator concentrate waste coming from PWR nuclear reactors. It was cemented using two formulations, A and B, incorporating higher or lower amount of waste, respectively. It was added chemical admixtures from two manufacturers (S and H), which were: accelerators, set retarders and superplasticizers. The experiments were organized by a factorial design 23. The measured parameters were: the viscosity, the setting time, the paste and product density and the compressive strength. The parameter evaluated in this study was the compressive strength at age of 28 days, is considered essential security issues relating to the handling, transport and storage of cemented waste product. The results showed that the addition of accelerators improved the compressive strength of the cemented products. (author)

  7. Results of cement augmentation and curettage in aneurysmal bone cyst of spine.

    Science.gov (United States)

    Basu, Saumyajit; Patel, Dharmesh R; Dhakal, Gaurav; Sarangi, T

    2016-01-01

    Aneurysmal bone cyst (ABC) is a vascular tumor of the spine. Management of spinal ABC still remains controversial because of its location, vascular nature and incidence of recurrence. In this manuscript, we hereby describe two cases of ABC spine treated by curettage, vertebral cement augmentation for control of bleeding and internal stabilization with two years followup. To the best of our knowledge, this is the first case report in the literature describing the role of cement augmentation in spinal ABC in controlling vascular bleeding in curettage of ABC of spine. Case 1: A 22 year old male patient presented with chronic back pain. On radiological investigation, there were multiple, osteolytic septite lesions at L3 vertebral body without neural compression or instability. Percutaneous transpedicular biopsy of L3 from involved pedicle was done. This was followed by cement augmentation through the uninvolved pedicle. Next, transpedicular complete curettage was done through involved pedicle. Case 2: A 15-year-old female presented with nonradiating back pain and progressive myelopathy. On radiological investigation, there was an osteolytic lesion at D9. At surgery, decompression, pedicle screw-rod fixation and posterolateral fusion from D7 to D11 was done. At D9 level, through normal pedicle cement augmentation was added to provide anterior column support and to control the expected bleeding following curettage. Transpedicular complete curettage was done through the involved pedicle with controlled bleeding at the surgical field. Cement augmentation was providing controlled bleeding at surgical field during curettage, internal stabilization and control of pain. On 2 years followup, pain was relieved and there was a stable spinal segment with well filled cement without any sign of recurrence in computed tomography scan. In selected cases of spinal ABC with single vertebral, single pedicle involvement; cement augmentation of vertebra through normal pedicle has an

  8. Results of cement augmentation and curettage in aneurysmal bone cyst of spine

    Directory of Open Access Journals (Sweden)

    Saumyajit Basu

    2016-01-01

    Full Text Available Aneurysmal bone cyst (ABC is a vascular tumor of the spine. Management of spinal ABC still remains controversial because of its location, vascular nature and incidence of recurrence. In this manuscript, we hereby describe two cases of ABC spine treated by curettage, vertebral cement augmentation for control of bleeding and internal stabilization with two years followup. To the best of our knowledge, this is the first case report in the literature describing the role of cement augmentation in spinal ABC in controlling vascular bleeding in curettage of ABC of spine. Case 1: A 22 year old male patient presented with chronic back pain. On radiological investigation, there were multiple, osteolytic septite lesions at L3 vertebral body without neural compression or instability. Percutaneous transpedicular biopsy of L3 from involved pedicle was done. This was followed by cement augmentation through the uninvolved pedicle. Next, transpedicular complete curettage was done through involved pedicle. Case 2: A 15-year-old female presented with nonradiating back pain and progressive myelopathy. On radiological investigation, there was an osteolytic lesion at D9. At surgery, decompression, pedicle screw-rod fixation and posterolateral fusion from D7 to D11 was done. At D9 level, through normal pedicle cement augmentation was added to provide anterior column support and to control the expected bleeding following curettage. Transpedicular complete curettage was done through the involved pedicle with controlled bleeding at the surgical field. Cement augmentation was providing controlled bleeding at surgical field during curettage, internal stabilization and control of pain. On 2 years followup, pain was relieved and there was a stable spinal segment with well filled cement without any sign of recurrence in computed tomography scan. In selected cases of spinal ABC with single vertebral, single pedicle involvement; cement augmentation of vertebra through normal

  9. Mechanical and thermal properties of castor oil polyurethane bone cement after gamma irradiation

    International Nuclear Information System (INIS)

    Polyurethanes from castor oil are being employed as bone cement in medical applications. In this work the thermal and mechanical properties of gamma irradiated polyurethanes derivative from castor oil were investigated by instrumented indentation, thermogravimetry and scanning electron microscopy. A slightly increase in hardness is observed only for doses as high as 100 kGy. Thermal analysis indicates stability at human body temperature. The glass transition temperature has small changes after gamma irradiation. (author)

  10. High resolution finite element modeling of cemented bone-implant interface using X-ray microtomography

    Czech Academy of Sciences Publication Activity Database

    Kytýř, Daniel; Jiroušek, Ondřej; Zlámal, Petr; Pokorný, D.; Dammer, J.

    Cardiff : ARUP, 2010 - (Middleton, J.), s. 467-471 ISBN 978-0-9562121-3-9. [International symposium on Computer methods in biomechanics and biomedial engineering /9./. Valencia (ES), 24.02.2010-27.02.2010] R&D Projects: GA ČR(CZ) GAP105/10/2305 Institutional research plan: CEZ:AV0Z20710524 Keywords : bone-cement interface * computed tomography * high-resolution models Subject RIV: FI - Traumatology, Orthopedics

  11. Experimental and numerical study of cemented bone-implant interface behaviour

    Czech Academy of Sciences Publication Activity Database

    Kytýř, Daniel; Doktor, Tomáš; Jiroušek, Ondřej; Zlámal, Petr; Pokorný, D.

    2011-01-01

    Roč. 15, č. 15 (2011), s. 5-13. ISSN 1971-8993 R&D Projects: GA ČR(CZ) GAP105/10/2305 Institutional research plan: CEZ:AV0Z20710524 Keywords : bone-cement interface * computed tomography * hip simulator * crack detection Subject RIV: FI - Traumatology, Orthopedics http://www.gruppofrattura.it/index.php?option=com_content&task=view&id=90&Itemid=284

  12. Experimental and numerical study of cemented bone-implant interface behaviour

    Czech Academy of Sciences Publication Activity Database

    Kytýř, Daniel; Doktor, Tomáš; Jiroušek, Ondřej; Zlámal, Petr; Pokorný, D.

    Trieste : Italian Group of Fracture, 2010 - (Iacoviello, F.; Cosmi, F.), s. 151-154 ISBN 978-88-95940-30-4. [Youth Symposium on Experimental Solid Mechanics /9./. Trieste (IT), 07.07.2010-10.07.2010] R&D Projects: GA ČR(CZ) GAP105/10/2305 Institutional research plan: CEZ:AV0Z20710524 Keywords : bone cement * cyclic loading * X-ray Subject RIV: JJ - Other Materials

  13. Disintegration of High Fatigue G Bone Cement and Palacos R+G® by Pulsating Water Jet

    Czech Academy of Sciences Publication Activity Database

    Hloch, S.; Foldyna, Josef; Hvizdoš, P.; Monka, P.; Ševčíková, X.; Magurová, D.; Kloc, J.; Zeleňák, Michal

    Zagreb : Croatian Assossiation of Production Engineering, 2013 - (Abele, E.; Udiljak, T.; Ciglar, D.), s. 124-127 ISBN 978-953-7689-02-5. [CIM 2013 Computer Integrated Manufacturing and High Speed Maching. Biograd (HR), 19.06.2013-22.06.2013] R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : pulsating water jet * jet bone cement * hardness Subject RIV: JQ - Machines ; Tools

  14. Experimental in-vitro bone cements disintegration with ultrasonic pulsating water jet for revision arthroplasty

    Czech Academy of Sciences Publication Activity Database

    Hloch, Sergej; Foldyna, Josef; Pude, F.; Kloc, J.; Zeleňák, Michal; Hvizdoš, P.; Monka, P.; Smolko, I.; Ščučka, Jiří; Kozak, D.; Sedmak, A.; Mihalčinová, E.

    2015-01-01

    Roč. 22, č. 6 (2015), s. 1609-1616. ISSN 1330-3651 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support : RVO:68145535 Keywords : bone cement * revision arthroplasty * ultrasonic pulsating water jet Subject RIV: JQ - Machines ; Tools Impact factor: 0.579, year: 2014 http://www.tehnicki-vjesnik.com/web/public/archive

  15. Microencapsulation of 2-octylcyanoacrylate tissue adhesive for self-healing acrylic bone cement

    OpenAIRE

    Brochu, Alice B. W.; Chyan, William J.; Reichert, William M

    2012-01-01

    Here, we report the first phase of developing self-healing acrylic bone cement: the preparation and characterization of polyurethane (PUR) microcapsules containing a medical cyanoacrylate tissue adhesive. Capsules were prepared by interfacial polymerization of a toluene-2,4-diisocyanate-based polyurethane prepolymer with 1,4-butanediol to encapsulate 2-octylcyanoacrylate (OCA). Various capsule characteristics, including: resultant morphology, average size and size distribution, shell thicknes...

  16. New starch-based thermoplastic hydrogels for use as bone cements or drug-delivery carriers

    OpenAIRE

    C.S. Pereira; Vásquez, Blanca; A.M. Cunha; Reis, R.L.; San Román, J.

    1998-01-01

    The development of new biodegradable hydrogels, based on corn starch/cellulose acetate blends, produced by free-radical polymerization with methyl methacrylate monomer (MMA) and/or an acrylic acid monomer (AA), is reported. The polymerization was initiated by a redox system consisting of a benzoyl peroxide and 4-dimethlyaminobenzyl alcohol at low temperature. These hydrogels may constitute an alternative to the materials currently used as bone cements or drug-delivery carriers. Swelling studi...

  17. Microstructure engineering of Portland cement pastes and mortars through addition of ultrafine layer silicates

    DEFF Research Database (Denmark)

    Lindgreen, Holger; Geiker, Mette Rica; Krøyer, Hanne;

    2008-01-01

    Pozzolanic submicron-sized silica fume and the non-pozzolanic micron- and nano-sized layer silicates (clay minerals) kaolinite, smectite and palygorskite have been used as additives in Portland cement pastes and mortars. These layer silicates have different particle shape (needles and plates......, in comparison to the pure cement pasta and the paste containing kaolinite, a more open pore structure consisting of fine pores. Silica fume paste contains a significant amount of closed pores. As a secondary result, it is demonstrated that both the degree and duration of sample drying strongly modifies...

  18. Animated sulfonated or sulformethylated lignins as cement fluid loss control additives

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, P.

    1991-05-07

    This patent describes a method of cementing a zone in a well penetrating a subterranean formation comprising injecting down the well and positioning in the zone to be cemented a hydraulic aqueous cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and a fluid loss control additive comprising from about 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been aminated by reacting it with between about 2-5 moles of a polyamine and 2-5 moles of an aldehyde per 1,000g of the lignin, and 0.1 to 1.5 parts of a compound selected from the group consisting of sodium carbonate, sodium metasilicate, sodium phosphate, sodium sulfite and sodium naphthalene sulfonate and a combination thereof.

  19. Antibiotic bone cement and renovation after artificial joint replacement%抗生素骨水泥与人工关节置换后的翻修

    Institute of Scientific and Technical Information of China (English)

    李文成

    2013-01-01

    BACKGROUND:Antibiotic bone cement is the important method for the prevention and treatment of infection after artificial hip replacement and renovation. OBJECTIVE:To review the research progress of antibiotic bone cement. METHODS:A computer-based online search was performed in PubMed database, CNKI database, Chinese Biomedical Literature database, VIP database and Wanfang database for the literatures from 1978 to 2012. The key words were“bone cement, antibiotic bone cement, infection, joint replacement”in English and Chinese. RESUTLS AND CONCLUSION:A total of 335 literatures were screened out. Final y, 29 literatures were included for in-depth analysis after the primary screen through reading the title, abstract and ful-text. Antibiotic bone cement has been widely used in the treatment of infection after artificial joint replacement and renovation as it can reduce the risk of infection after initial joint replacement and renovation. The material properties and mechanical properties wil not change after bone cement mixed with appropriate amount of antibiotic. Different antibiotics in the bone cement have different release rates, which were closely related with the porosity of bone cement. Adding the additive that used for increasing the porosity of bone cement can increase the antibiotic release.%  背景:抗生素骨水泥是预防和治疗人工关节置换以及翻修后感染的重要方法。目的:综述抗生素骨水泥的研究进展以及人工关节置换后翻修。方法:通过计算机检索Pubmed数据库、中国知网数据库、中国生物医学文献数据库、维普期刊全文数据库、万方数据库,时间范围在1978年至2012年,中文检索词“骨水泥”、“抗生素骨水泥”、“感染”、“关节置换”;英文检索词“bone cement”、“antibiotic bone cement”、“infection”、“joint replacement”。结果与结论:共检索到相关文献335篇。通过阅读标题、摘要以及全

  20. Healing of segmental ulnar defects in dog using bioresorbable calcium phosphate cement added with recombinant human bone morphogenetic protein-2

    Energy Technology Data Exchange (ETDEWEB)

    Ohura, K.; Hamanishi, C. [Kinki Univ. School of Medicine, Osaka (Japan). Dept. of Orthopaedic Surgery; Irie, H. [Olympus Optical Co., Ltd., Tokyo (Japan)

    2001-07-01

    Bioresorbable calcium phosphate cement (BCPC) cylinders soaked with 100 {mu}g of rhBMP-2 were implanted into 21 mm segmental ulnar defects in dogs. New bone induced around cylinders united both bone segments in 3 weeks. As the cylinder dissolved, the induced bone was remodeled into the compact bone by 9 weeks. However, the cement cylinder implanted without BMP did not dissolve and that defect did not recover bone continuity in 9 weeks. Mechanical test at 9 weeks showed that the BMP group achieved 71% union and 63% of bone strength compared to normal ulna. However, other two groups, the implantation of the cylinder alone and no implantation, did not unite any case. The implantation of thin cylinders of BCPC soaked with small amount of rhBMP-2 repaired large bone defects of high mammal fast. Added with more BMP, it will be possible to apply this biocompatible composite even in clinical cases. (orig.)

  1. The effect of adding tobramycin to Simplex P cement on femoral stem micromotion as measured by radiostereometric analysis

    OpenAIRE

    Bohm, Eric; Petrak, Martin; Gascoyne, Trevor; Turgeon, Thomas

    2012-01-01

    Background Previous in vitro research on addition of antibiotics to bone cement has found no statistically significant deterioration in mechanical properties. However, no clinical studies have compared the performance of tobramycin-laden bone cement with that of standard bone cement (Simplex P). Patients and Methods 23 patients (25 hips) were randomized to receive an Exeter (Stryker Orthopaedics) femoral stem cemented with either Simplex P (standard) or Simplex T (tobramycin-laden) cement. Th...

  2. Carboxymethylation of ulvan and chitosan and their use as polymeric components of bone cements.

    Science.gov (United States)

    Barros, A A A; Alves, A; Nunes, C; Coimbra, M A; Pires, R A; Reis, R L

    2013-11-01

    Ulvan, extracted from the green algae Ulva lactuca, and chitosan, extracted from Loligo forbesis squid-pen, were carboxymethylated, yielding polysaccharides with an average degree of substitution of ∼98% (carboxymethyl ulvan, CMU) and ∼87% (carboxymethyl chitosan, N,O-CMC). The carboxymethylation was confirmed by Fourier transform infrared spectroscopy and quantified by conductimetric titration and 1H nuclear magnetic resonance. The average molecular weight increased with the carboxymethylation (chitosan, Mn 145→296 kDa and Mw 227→416 kDa; ulvan, Mn 139→261 kDa and Mw 368→640 kDa), indicating successful chemical modifications. Mixtures of the modified polysaccharides were tested in the formulation of polyacrylic acid-free glass-ionomer bone cements. Mechanical and in vitro bioactivity tests indicate that the inclusion of CMU in the cement formulation, i.e. 0.50:0.50 N,O-CMC:CMU, enhances its mechanical performance (compressive strength 52.4±8.0 MPa and modulus 2.3±0.3 GPa), generates non-cytotoxic cements and induces the diffusion of Ca and/or P-based moieties from the surface to the bulk of the cements. PMID:23816652

  3. Towards optimization of the silanization process of hydroxyapatite for its use in bone cement formulations

    Energy Technology Data Exchange (ETDEWEB)

    Cisneros-Pineda, Olga G.; Herrera Kao, Wilberth; Loría-Bastarrachea, María I. [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Veranes-Pantoja, Yaymarilis [Centro de Biomateriales, Universidad de la Habana, Avenida Universidad, s/n, e/G y Ronda, C.P. 10600 C. de La Habana (Cuba); Cauich-Rodríguez, Juan V. [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Cervantes-Uc, José M., E-mail: manceruc@cicy.mx [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico)

    2014-07-01

    The aim of this work was to provide some fundamental information for optimization of silanization of hydroxyapatite intended for bone cement formulations. The effect of 3-(trimethoxysilyl) propyl methacrylate (MPS) concentration and solvent system (acetone/water or methanol/water mixtures) during HA silanization was monitored by X-ray diffraction (XRD), FTIR spectroscopy and EDX analysis. The effect of silanized HA on the mechanical properties of acrylic bone cements is also reported. It was found that the silanization process rendered hydroxyapatite with lower crystallinity compared to untreated HA. Through EDX, it was observed that the silicon concentration in the HA particles was higher for acetone–water than that obtained for methanol–water system, although the mechanical performance of cements prepared with these particles exhibited the opposite behavior. Taking all these results together, it is concluded that methanol–water system containing MPS at 3 wt.% provides the better results during silanization process of HA. - Highlights: • Effect of MPS concentration and solvents during HA silanization was studied. • Silanization rendered HA has lower crystallinity compared to untreated HA. • Silicon concentration was higher for acetone than that obtained using methanol. • Methanol–water system containing MPS at 3 wt.% provides the better results.

  4. Giant Cell Tumor Of The Long Bones: Results With Combination Of Cryosurgery, Curettage, And Cementation

    Directory of Open Access Journals (Sweden)

    Mortazavi S.M.J

    2005-07-01

    Full Text Available Background: In this study we evaluated the treatment of giant cell tumor (GCT of long bones using cryosurgery combined with curettage and polymethylmetacrylate (PMMA cementing. Material and methods: From January 1999 to December 2004, twenty patients (mean age at the time of surgery 29.2 years; 13 females and 7 males; were included in the study. Cortical disruption were presented in 7 patients; 4 with soft tissue extension, but none of them had intra-articular extension of tumor, 3 patients presented with pathologic fracture of distal femoral lesions. These tumors were located in distal femur in 6 patients, proximal tibia in 7, distal radius in 3, proximal femur in 2, and each of proximal humerus and distal ulna in one patient. In each case diagnostic biopsy was done and surgical procedure performed including curettage, power burr of the wall, cryosurgery with liquid nitrogen and finally filling the space with PMMA cementing. The mean follow-up was 34 months (7 to 61 . Results: During follow-up, we observed one recurrence of GCT of proximal tibia. Secondary Aneurysmal bone cyst was reported at the site of one primary distal femoral lesion, without any finding in favor of a recurrence. Neurapraxia of the proneal nerve was occurred in one patient with proximal tibia tumor improved after 8 months. Conclusion: Cryosurgery combined with power burr and PMMA cementing in the treatment of GCT could be an effective approach in tumor eradication. This method obviates the need for extensive resections and reconstructive procedure.

  5. THE STUDY OF OUTCOME OF CHRONIC PYOGEN IC LONG BONE OSTEOMYELITIS TREATED BY ANTIBIOTIC IMPREGNATED BONE CEMENT BEADS AND NAILS

    Directory of Open Access Journals (Sweden)

    Soumyajit

    2015-01-01

    Full Text Available OBJECTIVE: In developing country the incidence of chronic pyogenic infection of long bone is high among children and adults. This entity is difficult to be managed by conventional systemic antibiotics alone. Many treatment methods for long bone osteomyelitis were attempted but unfortunately the eradication of chronic osteomyelitis remains a problem. Local antibiotic therapy has been introduced by arthroplasty surgeons and subsequently this method has been tried for treating chronic osteomyelitis. Treatment of chronic osteomyelitis using antibiotic - impregnated bone cement beads or nail after thorough debride ment has become a good option of treatment. Therefore this prospective study has been designed to evaluate the effect of local antibiotic therapy in the form of bone cement beads or nail for eradication of chronic pyogenic long bone osteomyelitis. METHODS: Thirty patients with chronic osteomyelitis of metaphyseal and diaphyseal area of long bones were studied prospectively about outcome of treatment. The diagnosis of chronic osteomyelitis was made on the basis of clinical and radiological features and confirmed by deep aspiration, staining and culture sensitivity of the aspirate. Patients suffering from fungal or tubercular osteomyelitis were excluded. Also the patients with small bones osteomyelitis or open injury more than Gustilo type 2 were excluded. Antibiotic impregnated polymethylmethacrylate beads or nails were implanted after thorough debridement and wound closed primarily. Two dose of intervenous antibiotic were used, one before and another after operation. Beads or nails were removed at the end of six weeks. Patients were followed up for an average period of two years. RESULT: Out of thirty patients in this study, twenty eight patients were cured completely and two patients had persistent discharge till the last follow up visit. No organism found in six cases. No systemic adverse reactions were seen. CONCLUSION: The present study

  6. Peen treatment on a titanium implant: effect of roughness, osteoblast cell functions, and bonding with bone cement

    Directory of Open Access Journals (Sweden)

    Khandaker M

    2016-02-01

    Full Text Available Morshed Khandaker,1,4 Shahram Riahinezhad,1 Fariha Sultana,1 Melville B Vaughan,2,4 Joshua Knight,2 Tracy L Morris3,4 1Department of Engineering & Physics, 2Department of Biology, 3Department of Mathematics and Statistics, 4Center for Interdisciplinary Biomedical Education and Research, University of Central Oklahoma, Edmond, OK, USA Abstract: Implant failure due to poor integration of the implant with the surrounding biomaterial is a common problem in various orthopedic and orthodontic surgeries. Implant fixation mostly depends upon the implant surface topography. Micron to nanosize circular-shaped groove architecture with adequate surface roughness can enhance the mechanical interlock and osseointegration of an implant with the host tissue and solve its poor fixation problem. Such groove architecture can be created on a titanium (Ti alloy implant by laser peening treatment. Laser peening produces deep, residual compressive stresses in the surfaces of metal parts, delivering increased fatigue life and damage tolerance. The scientific novelty of this study is the controlled deposition of circular-shaped rough spot groove using laser peening technique and understanding the effect of the treatment techniques for improving the implant surface properties. The hypothesis of this study was that implant surface grooves created by controlled laser peen treatment can improve the mechanical and biological responses of the implant with the adjoining biomaterial. The objective of this study was to measure how the controlled laser-peened groove architecture on Ti influences its osteoblast cell functions and bonding strength with bone cement. This study determined the surface roughness and morphology of the peen-treated Ti. In addition, this study compared the osteoblast cell functions (adhesion, proliferation, and differentiation between control and peen-treated Ti samples. Finally, this study measured the fracture strength between each kind of Ti samples

  7. Effect of Carbon Addition on Microstructure and Properties of WC-Co Cemented Carbides

    Institute of Scientific and Technical Information of China (English)

    Chongbin Wei; Xiaoyan Song; Jun Fu; Xiaosen Lv; Haibin Wang; Yang Cao; ShixianZhao; Xuemei Liu

    2012-01-01

    Based on a unique method to synthesize WC-Co composite powder by in-situ reactions of metal oxides and carbon, the effects of the carbon addition in the initial powders on the phase constitution, microstructure and mechanical properties of the cemented carbides were investigated. It is found that with a suitable carbon addition the pure phase constitution can be obtained in the sintered bulk from the composite powder. The mechanical properties of the cemented carbides depend on the phase constitution and the WC grain structure. To obtain the excellent properties of the WC-Co bulk, it is important to obtain the pure phase constitution from the appropriate carbon addition in the initial powders and a suitable grain size.

  8. Addition of cement to lime-based mortars: Effect on pore structure and vapor transport

    International Nuclear Information System (INIS)

    The main focus of this work is to determine the effect of cement addition, a common practice in many restorations, on the pore structure of lime-based mortars. A second target is to establish correlations between microstructure and water vapor transport across the mortar, which is a key characteristic of building decay. In order to achieve these objectives, we prepared a set of mortars consisting of air-hardening lime with a progressively increasing cement content, as well as a mortar containing hydraulic lime. Several different techniques, most notably mercury intrusion porosimetry and scanning electron microscopy in the backscatter mode, were used to investigate the pore structure. The results from these procedures led to the conclusion that porosity and pore size are progressively reduced as cement content increases. Moreover, an excellent correlation between pore radius parameter and the vapor diffusion coefficient was established. Hydraulic lime mortar exhibited textural parameters and diffusivity values halfway between those of the different lime/cement mixes studied

  9. Temperature Measurement During Polymerization of Bone Cement in Percutaneous Vertebroplasty: An In Vivo Study in Humans

    International Nuclear Information System (INIS)

    Aim of the study was to 'in vivo' measure temperature, during percutaneous vertebroplasty (PV), within a vertebral body injected with different bone cements. According to the declaration of Helsinki, 22 women (60-80 years; mean, 75 years) with painful osteoporotic vertebral collapse underwent bilateral transpedicular PV on 22 lumbar vertebrae. Two 10-G vertebroplasty needles were introduced into the vertebra under digital fluoroscopy; a 16-G radiofrequency thermoablation needle (Starburst XL; RITA Medical System Inc., USA), carrying five thermocouples, was than coaxially inserted. Eleven different bone cements were injected and temperatures were measured every 30 s until temperatures dropped under 45oC. After the thermocouple needle was withdrawn, bilateral PV was completed with cement injection through the vertebroplasty needle. Unpaired Student's t-tests, Kruskal-Wallis test, and Wilcoxon signed rank test were used to evaluate significant differences (p oC), B (from 50o to 60oC), and C (below 50oC). Peak temperature in Group A (86.7 ± 10.7oC) was significantly higher (p = 0.0172) than that in Groups B (60.5 ± 3.7oC) and C (44.8 ± 2.6oC). The average of all thermocouples showed an extremely significant difference (p = 0.0002) between groups. None of the tested cements maintained a temperature ≥45oC for more than 30 min. These data suggest that back-pain improvement is obtained not by thermal necrosis but by mechanical consolidation only. The relative necrotic thermal effect in vertebral metastases seems to confirm that analgesia must be considered the main intent of PV.

  10. Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guangyong [Department of Orthopaedics, Taizhou Hospital of Zhejiang Province, Linhai Zhejiang, 317000 (China); Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Liu, Jianli [Trauma Center, Affiliated Hospital of Hainan Medical University, Haikou, Hainan, 570206 (China); Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang, 315201 (China); Li, Fan; Pan, Zongyou; Ni, Xiao; Shen, Yue [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Xu, Huazi, E-mail: spinexu@163.com [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Huang, Qing, E-mail: huangqing@nimte.ac.cn [Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang, 315201 (China)

    2014-02-01

    A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6–12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration. - Highlights: • The mechanical strength and degradation rate of CSMPC composites are discussed. • The CSMPC composites exhibited good bioactivity to form bone-like apatite. • The CSMPC composites also show good biocompatibility.

  11. Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications

    International Nuclear Information System (INIS)

    A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6–12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration. - Highlights: • The mechanical strength and degradation rate of CSMPC composites are discussed. • The CSMPC composites exhibited good bioactivity to form bone-like apatite. • The CSMPC composites also show good biocompatibility

  12. Spatial resolution and measurement uncertainty of strains in bone and bone-cement interface using digital volume correlation.

    Science.gov (United States)

    Zhu, Ming-Liang; Zhang, Qing-Hang; Lupton, Colin; Tong, Jie

    2016-04-01

    The measurement uncertainty of strains has been assessed in a bone analogue (sawbone), bovine trabecular bone and bone-cement interface specimens under zero load using the Digital Volume Correlation (DVC) method. The effects of sub-volume size, sample constraint and preload on the measured strain uncertainty have been examined. There is generally a trade-off between the measurement uncertainty and the spatial resolution. Suitable sub-volume sizes have been be selected based on a compromise between the measurement uncertainty and the spatial resolution of the cases considered. A ratio of sub-volume size to a microstructure characteristic (Tb.Sp) was introduced to reflect a suitable spatial resolution, and the measurement uncertainty associated was assessed. Specifically, ratios between 1.6 and 4 appear to give rise to standard deviations in the measured strains between 166 and 620 με in all the cases considered, which would seem to suffice for strain analysis in pre as well as post yield loading regimes. A microscale finite element (μFE) model was built from the CT images of the sawbone, and the results from the μFE model and a continuum FE model were compared with those from the DVC. The strain results were found to differ significantly between the two methods at tissue level, consistent in trend with the results found in human bones, indicating mainly a limitation of the current DVC method in mapping strains at this level. PMID:26741534

  13. Improved cement mortars by addition of carbonated fly ash from solid waste incinerators

    OpenAIRE

    López-Zaldívar, O.; Mayor-Lobo, P. L.; Fernández-Martínez, F.; Hernández-Olivares, F.

    2015-01-01

    This article presents the results of a research developing high performance cement mortars with the addition of municipal solid waste incineration fly ash (MSWIFA) stabilized as insoluble carbonates. The encapsulation of hazardous wastes in mortar matrixes has also been achieved. The ashes present high concentrations of chlorides, Zn and Pb. A stabilization process with NaHCO3 has been developed reducing 99% the content of chlorides. Developed mortars replace 10% per weight of the aggregates ...

  14. Bone cement enhanced pedicle screw fixation combined with vertebroplasty for elderly patients with malignant spinal tumors

    Institute of Scientific and Technical Information of China (English)

    TAN Jiang-wei; SHEN Bing-hua; DU Wei; LIU Jiang-qing; LU Shi-qiao

    2013-01-01

    Background Older patients with malignant spinal tumors are difficult to treat because they have many co-morbidities including osteoporosis.The purpose of this research is to discuss the technique and clinical outcome of bone cement enhanced pedicle screw fixation combined with vertebroplasty (the Sandwich Procedure) for elderly patients with severe osteoporosis and malignant spinal tumors.Methods This study includes 28 consecutive elderly patients with malignant thoracic or lumbar spinal tumors.There were nine patients with myelomas,and 19 patients with metastatic bone tumors.The Sandwich Procedure began with curettage of the tumor and a vertebroplasty with bone cement (polymethyl methacrylate,PMMA),followed by PMMA enhanced pedicle screw fixation.Patients were evaluated with the visual analogue scale (VAS),oswestry disability index (ODI),American Spinal Cord Injury Association (ASIA) neurological function classification,and the radiographic degree of kyphosis (Cobb angle).Data were analyzed using paired t-test to compare the pre-and post-operative values.The complications,local recurrences,and the survival status were also recorded.Results There was no operative mortality,and the mean operative time was 210 minutes (range 150-250 minutes).The average blood loss was 1550 ml (range 650-3300 ml).The average amount of cement for vertebroplasty was 3.6 ml (range 3-5 ml).The VAS,ODI,and ASIA scores were significantly improved after surgery (P <0.05).However,we found no differences between the pre and post-operative Cobb angles.The shortest survival time was 3 months,and we found no evidence of local recurrence in this group of patients.Conclusion The Sandwich Procedure is a safe operation and provides symptomatic relief in these difficult patients,permitting further treatment with chemotherapy or radiotherapy.

  15. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Verné, Enrica, E-mail: enrica.verne@polito.it [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Bruno, Matteo [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Miola, Marta [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Maina, Giovanni; Bianco, Carlotta [Traumatology Orthopedics and Occupational Medicine Dept., Università di Torino, Via G. Zuretti 29, 10126 Torino (Italy); Cochis, Andrea [Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Rimondini, Lia [Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9, 50121 Firenze (Italy)

    2015-08-01

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO{sub 2}–Na{sub 2}O–CaO–P{sub 2}O{sub 5}–FeO–Fe{sub 2}O{sub 3} and contains magnetite (Fe{sub 3}O{sub 4}) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite – HAp – layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. - Highlights: • An in vitro biological characterization was carried out on ferromagnetic and bioactive composite cements. • No release of iron was revealed in the physiological solution. • Bioactivity tests

  16. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility

    International Nuclear Information System (INIS)

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO2–Na2O–CaO–P2O5–FeO–Fe2O3 and contains magnetite (Fe3O4) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite – HAp – layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. - Highlights: • An in vitro biological characterization was carried out on ferromagnetic and bioactive composite cements. • No release of iron was revealed in the physiological solution. • Bioactivity tests show hydroxyapatite precipitates on the cement

  17. Preliminary analysis of volume material removal at bone cement disintegration by pulsating water jet

    Czech Academy of Sciences Publication Activity Database

    Lehocká, D.; Hloch, S.; Foldyna, Josef; Monka, P.; Monková, K.; Brezíková, K.

    Ostrava : Ústav geoniky AV ČR, 2013 - (Sitek, L.; Klichová, D.), s. 145-153 ISBN 978-80-86407-43-2. [Vodní paprsek 2013 - výzkum, vývoj, aplikace. Soláň, Karolinka (CZ), 22.10.2013-24.10.2013] R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : pulsating water jet * PMMA - bone cement * volume removal Subject RIV: JQ - Machines ; Tools

  18. A new method for identification of cement lines in undecalcified, plastic embedded sections of bone.

    Science.gov (United States)

    Villanueva, A R; Sypitkowski, C; Parfitt, A M

    1986-03-01

    A gallocyanin method for demonstrating cement lines in thin, undecalcified sections of bone has been developed that is compatible with prestaining with osteochrome before plastic embedding. After sectioning at 5 microns on the Jung K heavy duty microtome, the sections are attached to a microslide using Haupt's adhesive mounting medium, placed on a slide warmer at 37 C until completely dry, and deplasticized in xylene at 45 C for 16-24 hr. Sections are stained with 0.15% gallocyanin-5% chrome alum solution for 30 min, followed by staining in buffered Villanueva blood stain for 1-1 1/2 hr, quickly dehydrated, differentiated in equal parts xylene and 100% ethanol, cleared, and mounted in Eukitt's medium. Reversal lines appear as thin, scalloped, blue or purple lines approximately 0.3 micron wide, and arrest lines as thick, homogeneous, straight or evenly curved, dark blue or purple lines approximately 2 microns wide. The method also demonstrates abnormal halo volumes around osteocytes, old and new bone matrix, osteoid seams, and the granular mineralization front at the osteoid-bone interface. It promises to be valuable in the study of age-related bone loss, osteoporosis, and metabolic bone disease. PMID:2424150

  19. Reducing the permeability of cement by the use of commercially available additives

    International Nuclear Information System (INIS)

    The American Nuclear Society, in anticipation of Federal regulations in the area of waste leachability, formed the ANS 16.1 Working Group to develop a standardized leachability test method. In response to these trends Hittman Nuclear and Development Corporation (HITTMAN) has undertaken a substantial Research and Development program for the evaluation and possible improvement in the quality of cement solidified low-level nuclear power plant wastes. Starting with a series of leach tests, the results of which are in general agreement with previously referenced works, the authors embarked on a program to test and evaluate various commercially available additives designed to reduce the permeability of cement. This report discusses why permeability was considered an important factor, the materials tested, the method of testing and their results

  20. Material properties and in vitro biocompatibility of a newly developed bone cement

    Directory of Open Access Journals (Sweden)

    Elke Mitzner

    2009-01-01

    Full Text Available In this study mechanical properties and biocompatibility (In Vitro of a new bone cement were investigated. A new platform technology named COOL is a variable composite of dissolved, chemically modified PMMA and different bioceramics. COOL cures at body temperature via a classical cementation reaction. Compressive strengths ranging from 3.6 ± 0.8 to 62.8 ± 1.3 MPa and bending strengths ranging from 9.9 ± 2.4 to 26.4 ± 3.0 MPa were achieved with different COOL formulations. Porosity varied between 31 and 43%. Varying the components of each formulation mechanical properties and porosity could be adjusted. In Vitro biocompatibility studies with primary human osteoblasts (pHOB in direct contact with different COOL formulations, did not reveal any signs of toxicity. In contrast to Refobacin® R, cells incubated with COOL showed similar density, viability and ALP activity compared to control, if specimen were added immediately to the cell monolayer after preparation. In conclusion, COOL has promising mechanical properties in combination with high biocompatibility In Vitro and combines different advantages of both CPCs and PMMA cements by avoiding some of the respective shortcomings.

  1. Effect of the addition of nanosilica on white cement hydration at 25°C

    Directory of Open Access Journals (Sweden)

    Sáez del Bosque I.F.

    2014-04-01

    Full Text Available The cement industry is keen on reducing natural resource consumption, reusing waste that would otherwise be sent to a rubbish tip and lowering its CO2 emissions. In pursuit of those objectives, the addition of materials such as silica fume, ceramic waste, rice husk and precipitated or colloidal nanosilica, in the various stages of cement manufacture has become increasingly common. That practice inspired the present study (using isothermal conduction calorimetry, 29Si and 27Al MAS NMR, XRD and DTA/TG of the effect of precipitated amorphous nanosilica (10 wt% on white portland cement (WPC hydration. The isothermal conduction calorimetry findings, which were consistent with the NMR and DTA/TG results, showed that adding amorphous nanosilica altered reaction kinetics, expediting alite and belite hydration. The addition also intensified the heat flow attributed to alumina phase hydration and brought the respective peak forward. Although no general consensus has been reached in the literature on the attribution of the third peak appearing on the calorimetric curve for WPC, based on the present findings, the main aluminate hydrate product is monosulfoaluminate. Furthermore, a pre-peak inflection point on the profile of the first exothermal peak on the WPC calorimetric curve was interpreted as the beginning of the pozzolanic reaction, which accelerates alite hydration, consuming portlandite and raising the heat released. C-S-H gel nanostructure was also modified. The results revealed a linear relationship in both the blended and the pure cement pastes between the degree of hydration and the number of Q1 and Q2 units in the gel. The presence of Q2 units was much greater and of Q1 units slightly lower in the former than in the latter.

  2. Improved workability of injectable calcium sulfate bone cement by regulation of self-setting properties

    International Nuclear Information System (INIS)

    Calcium sulfate hemihydrate (CSH) powder as an injectable bone cement was prepared by hydrothermal synthesis of calcium sulfate dihydrate (CSD). The prepared materials showed X-ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from CSD phase to CSH phase. Thermogravimetric (TG) analyses showed the crystal water content of CSH was about 6.0% (wt.), which is near to the theoretic crystal water value of CSH. From scanning electron microscopy (SEM) micrographs, sheet crystal structure of CSD was observed to transform into rod-like crystal structure of CSH. Most interesting and important of all, CSD as setting accelerator was also introduced into CSH powder to regulate self-setting properties of injectable CSH paste, and thus the self-setting time of CSH paste can be regulated from near 30 min to less than 5 min by adding various amounts of setting accelerator. Because CSD is not only the reactant of preparing CSH but also the final solidified product of CSH, the setting accelerator has no significant effect on the other properties of materials, such as mechanical properties. In vitro biocompatibility and in vivo histology studies have demonstrated that the materials have good biocompatibility and good efficacy in bone regeneration. All these will further improve the workability of CSH in clinic applications. Highlights: ► Calcium sulfate hemihydrate (CSH) can be an injectable bone cement. ► CSH was produced by hydrothermal synthesis of calcium sulfate dihydrate (CSD). ► CSD was introduced into CSH powder to regulate self-setting properties of CSH. ► Setting accelerator has no significant effect on the other properties of materials. ► Injectable CSH has good biocompatibility and good efficacy in bone regeneration

  3. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility.

    Science.gov (United States)

    Verné, Enrica; Bruno, Matteo; Miola, Marta; Maina, Giovanni; Bianco, Carlotta; Cochis, Andrea; Rimondini, Lia

    2015-08-01

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO2-Na2O-CaO-P2O5-FeO-Fe2O3 and contains magnetite (Fe3O4) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite - HAp - layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. PMID:26042695

  4. Improved workability of injectable calcium sulfate bone cement by regulation of self-setting properties

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zonggang, E-mail: chenzg@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, Huanye [Department of Orthodontics, School of Stomatology, China Medical University, Shenyang 110001 (China); Liu, Xi [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Lian, Xiaojie [College of Mechanics, Taiyuan University of Technology, Taiyuan 030024 (China); Guo, Zhongwu [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Jiang, Hong-Jiang [Wendeng Hospital of Traditional Chinese Orthopedics and Traumatology, Shandong 264400 (China); Cui, Fu-Zhai, E-mail: cuifz@mail.tsinghua.edu.cn [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2013-04-01

    Calcium sulfate hemihydrate (CSH) powder as an injectable bone cement was prepared by hydrothermal synthesis of calcium sulfate dihydrate (CSD). The prepared materials showed X-ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from CSD phase to CSH phase. Thermogravimetric (TG) analyses showed the crystal water content of CSH was about 6.0% (wt.), which is near to the theoretic crystal water value of CSH. From scanning electron microscopy (SEM) micrographs, sheet crystal structure of CSD was observed to transform into rod-like crystal structure of CSH. Most interesting and important of all, CSD as setting accelerator was also introduced into CSH powder to regulate self-setting properties of injectable CSH paste, and thus the self-setting time of CSH paste can be regulated from near 30 min to less than 5 min by adding various amounts of setting accelerator. Because CSD is not only the reactant of preparing CSH but also the final solidified product of CSH, the setting accelerator has no significant effect on the other properties of materials, such as mechanical properties. In vitro biocompatibility and in vivo histology studies have demonstrated that the materials have good biocompatibility and good efficacy in bone regeneration. All these will further improve the workability of CSH in clinic applications. Highlights: ► Calcium sulfate hemihydrate (CSH) can be an injectable bone cement. ► CSH was produced by hydrothermal synthesis of calcium sulfate dihydrate (CSD). ► CSD was introduced into CSH powder to regulate self-setting properties of CSH. ► Setting accelerator has no significant effect on the other properties of materials. ► Injectable CSH has good biocompatibility and good efficacy in bone regeneration.

  5. Percutaneous vertebroplasty and bone cement leakage: clinical experience with a new high-viscosity bone cement and delivery system for vertebral augmentation in benign and malignant compression fractures.

    Science.gov (United States)

    Anselmetti, Giovanni Carlo; Zoarski, Gregg; Manca, Antonio; Masala, Salvatore; Eminefendic, Haris; Russo, Filippo; Regge, Daniele

    2008-01-01

    The aim of this study was to assess the feasibility of and venous leakage reduction in percutaneous vertebroplasty (PV) using a new high-viscosity bone cement (PMMA). PV has been used effectively for pain relief in osteoporotic and malignant vertebral fractures. Cement extrusion is a common problem and can lead to complications. Sixty patients (52 female; mean age, 72.2 +/- 7.2) suffering from osteoporosis (46), malignancy (12), and angiomas (2), divided into two groups (A and B), underwent PV on 190 vertebrae (86 dorsal, 104 lumbar). In Group A, PV with high-viscosity PMMA (Confidence, Disc-O-Tech, Israel) was used. This PMMA was injected by a proprietary delivery system, a hydraulic saline-filled screw injector. In Group B, a standard low-viscosity PMMA was used. Postprocedural CT was carried out to detect PMMA leakages and complications. Fisher's exact test and Wilcoxon rank test were used to assess significant differences (p < 0.05) in leakages and to evaluate the clinical outcome. PV was feasible, achieving good clinical outcome (p < 0.0001) without major complications. In Group A, postprocedural CT showed an asymptomatic leak in the venous structures of 8 of 98 (8.2%) treated vertebrae; a discoidal leak occurred in 6 of 98 (6.1%). In Group B, a venous leak was seen in 38 of 92 (41.3%) and a discoidal leak in 12 of 92 (13.0%). Reduction of venous leak obtained by high-viscosity PMMA was highly significant (p < 0.0001), whereas this result was not significant (p = 0.14) related to the disc. The high-viscosity PMMA system is safe and effective for clinical use, allowing a significant reduction of extravasation rate and, thus, leakage-related complications. PMID:18389186

  6. Percutaneous bone cement refixation of aseptically loose hip prostheses: the effect of interface tissue removal on injected cement volumes

    Energy Technology Data Exchange (ETDEWEB)

    Malan, Daniel F. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands); Delft University of Technology, Department of Intelligent Systems, Delft (Netherlands); Valstar, Edward R. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands); Delft University of Technology, Department of Biomechanical Engineering, Delft (Netherlands); Nelissen, Rob G.H.H. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands)

    2014-11-15

    To quantify whether injected cement volumes differed between two groups of patients who underwent experimental minimally invasive percutaneous cement injection procedures to stabilize aseptically loose hip prostheses. One patient group was preoperatively treated using gene-directed enzyme prodrug therapy to remove fibrous interface tissue, while the other group received no preoperative treatment. It was hypothesized that cement penetration may have been inhibited by the presence of fibrous interface tissue in periprosthetic lesions. We analyzed 17 patients (14 female, 3 male, ages 72-91, ASA categories 2-4) who were treated at our institution. Osteolytic lesions and injected cement were manually delineated using 3D CT image segmentation, and the deposition of injected cement was quantified. Patients who underwent preoperative gene-directed enzyme therapy to remove fibrous tissue exhibited larger injected cement volumes than those who did not. The observed median increase in injected cement volume was 6.8 ml. Higher cement leakage volumes were also observed for this group. We conclude that prior removal of periprosthetic fibrous interface tissue may enable better cement flow and penetration. This might lead to better refixation of aseptically loosened prostheses. (orig.)

  7. Percutaneous bone cement refixation of aseptically loose hip prostheses: the effect of interface tissue removal on injected cement volumes

    International Nuclear Information System (INIS)

    To quantify whether injected cement volumes differed between two groups of patients who underwent experimental minimally invasive percutaneous cement injection procedures to stabilize aseptically loose hip prostheses. One patient group was preoperatively treated using gene-directed enzyme prodrug therapy to remove fibrous interface tissue, while the other group received no preoperative treatment. It was hypothesized that cement penetration may have been inhibited by the presence of fibrous interface tissue in periprosthetic lesions. We analyzed 17 patients (14 female, 3 male, ages 72-91, ASA categories 2-4) who were treated at our institution. Osteolytic lesions and injected cement were manually delineated using 3D CT image segmentation, and the deposition of injected cement was quantified. Patients who underwent preoperative gene-directed enzyme therapy to remove fibrous tissue exhibited larger injected cement volumes than those who did not. The observed median increase in injected cement volume was 6.8 ml. Higher cement leakage volumes were also observed for this group. We conclude that prior removal of periprosthetic fibrous interface tissue may enable better cement flow and penetration. This might lead to better refixation of aseptically loosened prostheses. (orig.)

  8. Preliminary evaluation of the in vitro cytotoxicity of PMMA-co-EHA bone cement

    International Nuclear Information System (INIS)

    This work reports a preliminary in vitro cytotoxicity assessment of new poly (methyl methacrylate)-co-ethyl hexylacrylate (PMMA-co-EHA) bone cement by evaluating the effect of its leachables on the viability of human osteoblast-like cells (MG63 line) and their progression through the cell cycle. MG63 cells were exposed to 72 h-extract dilutions of PMMA-co-EHA and their viability was tested using the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Also, putative changes in the progression of cells through the cell cycle were monitored using flow cytometry. For that the relative nuclear DNA content and the ratio of cells at G1:S:G2 stages of the cell cycle were measured after three exposure periods (24, 48 and 72 h). The obtained results revealed a dose-dependent influence of the cement extract in MG63 cell metabolism when compared to cells cultivated in a culture medium only. The MTT assay showed that a moderate number of cells died after exposure to the most concentrated extract. The cell cycle analysis revealed that leachables of PMMA-co-EHA led to significant changes in cellular proliferation, with cells exposed for 48 h to the most concentrated extract being arrested in the S phase of the cell cycle. However, despite the initial period of cytotoxicity, the obtained results suggest that after 72 h of exposure, the surviving cells are able to recover from this arresting condition and continue to proliferate. Therefore, this preliminary study indicates that, at the biological level, PMMA-co-EHA may have potential of being used as a bone cement matrix. However, a more detailed research work is needed to fully understand the factors responsible for the initial cytotoxicity observed.

  9. Impact of Nano-Cr2O3 Addition on the Properties of Aluminous Cements Containing Spinel

    Directory of Open Access Journals (Sweden)

    Sasan OTROJ

    2015-05-01

    Full Text Available In this paper, the effect of nano-Cr2O3 addition on the properties of aluminous cement containing MgAl2O4 spinel was investigated. For this reason, the raw dolomite was used as raw material along with calcined alumina for the preparation of the aluminous cement. Then, the compositions containing different amounts of nano-Cr2O3 particles were fired at 1450 °C and their mineralogical compositions and microstructures were investigated. The setting times of prepared cements were measured after grounding and ball-milling. Besides, the slag resistance of refractory castables containing prepared cements was evaluated. The results showed that nano-Cr2O3 addition has effect on the increasing of spinel and CA2 and decreasing of CA and C12A7 phases in the cement composition. The decreasing of C12A7 leads to increasing of setting times of cement. Besides, the slag resistance of refractory castables containing prepared cements is improved due to increasing of spinel and decreasing of C12A7 amount in the cement composition.

  10. Characteristics and propierties of oil-well cements additioned with blast furnace slag

    OpenAIRE

    Sánchez, R.; Palacios, M.; Puertas, F.

    2011-01-01

    The present paper addresses the alkali activation of Portland cements containing blast furnace slag (20 and 30% of the cement by weight) with a view to the possible use of these materials in oil well construction. The hydration studies conducted showed that in cement/slag blends, the sodium silicate activating solution partially inhibited the dissolution of the silicate phases in the Portland cement, retarding cement hydration and reducing the precipitation of reaction products. D...

  11. Using calcium silicate to regulate the physicochemical and biological properties when using β-tricalcium phosphate as bone cement

    International Nuclear Information System (INIS)

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Regarding the formation of bone-like apatite, the diametral tensile strength as well as the ion release and weight loss of composites were compared both before and after immersions in simulated body fluid (SBF). In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on β-TCP/CS composites. The results show that the apatite deposition ability of the β-TCP/CS composites improves as the CS content is increased. For composites with more than a 60% CS content, the samples become completely covered by a dense bone-like apatite layer. At the end of the immersion period, weight losses of 24%, 32%, 34%, 38%, 41%, and 45% were observed for the composites containing 0%, 20%, 40%, 80%, 80% and 100% β-TCP cements, respectively. In addition, the antibacterial activity of CS/β-TCP composite improves as the CS-content is increased. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 60%, the quantity of cells and osteogenesis protein of hDPCs is stimulated by Si released from the β-TCP/CS composites. The degradation of β-TCP and the osteogenesis of CS give strong reason to believe that these calcium-based composite cements will prove to be effective bone repair materials. - Highlights: • CS improved the physicochemical properties and osteogenic activity of β-TCP. • Higher CS in the composite, the shorter setting time and the higher DTS was found. • With a CS more than 40%, the osteogenesis and angiogenesis proteins were promoted by

  12. Using calcium silicate to regulate the physicochemical and biological properties when using β-tricalcium phosphate as bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Chia-Tze; Huang, Tsui-Hsien [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Chen, Yi-Jyun [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Dental Department, Taichung Hospital, Ministry of Health and Welfare, Taichung City, Taiwan (China); Hung, Chi-Jr [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Lin, Chi-Chang, E-mail: chichang31@gmail.com [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China)

    2014-10-01

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Regarding the formation of bone-like apatite, the diametral tensile strength as well as the ion release and weight loss of composites were compared both before and after immersions in simulated body fluid (SBF). In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on β-TCP/CS composites. The results show that the apatite deposition ability of the β-TCP/CS composites improves as the CS content is increased. For composites with more than a 60% CS content, the samples become completely covered by a dense bone-like apatite layer. At the end of the immersion period, weight losses of 24%, 32%, 34%, 38%, 41%, and 45% were observed for the composites containing 0%, 20%, 40%, 80%, 80% and 100% β-TCP cements, respectively. In addition, the antibacterial activity of CS/β-TCP composite improves as the CS-content is increased. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 60%, the quantity of cells and osteogenesis protein of hDPCs is stimulated by Si released from the β-TCP/CS composites. The degradation of β-TCP and the osteogenesis of CS give strong reason to believe that these calcium-based composite cements will prove to be effective bone repair materials. - Highlights: • CS improved the physicochemical properties and osteogenic activity of β-TCP. • Higher CS in the composite, the shorter setting time and the higher DTS was found. • With a CS more than 40%, the osteogenesis and angiogenesis proteins were promoted by

  13. Application of labeled radioimmunoimaging tracing in detecting pulmonary embolism in rabbits after bone cement perfusion and relevant treatment effects

    Institute of Scientific and Technical Information of China (English)

    QI Xiang-bei; ZHANG Ying-ze; PAN Jin-she; MA Li-jie; WANG Jian-zhao; WANG Lin

    2011-01-01

    Background During the process of bone cement joint replacement,some patients show a series of complications,such as a sudden drop in blood pressure or dyspnea.The cause of the complication is considered to be due to emboli caused by the femur prosthesis insertion.The purpose of the present study was to detect the pulmonary embolism in rabbits after bone cement perfusion by radioimmunoimaging,and to explore its protective measures.Methods Forty rabbits,2.5-3.0 kg weight,were randomly assigned to four groups,with ten rabbits in each group.Group Ⅰ (no intervention):Bone cement perfusion was done after medullary cavity reaming and pressurizing.Group Ⅱ (epinephrine hydrochloride intervention):The medullary cavity was rinsed with a 1:10000 normal saline-diluted epinephrine hydrochloride solution followed by bone cement perfusion after medullary cavity reaming and pressurizing.Group Ⅲ (fibrin sealant intervention):The medullary cavity was precoated with fibrin sealant followed by bone cement perfusion after medullary cavity reaming and pressurizing.Group Ⅳ (blank control group):The medullary cavity was not perfused with bone cement after reaming.In each group,the rabbits underwent femoral head resection and medullary cavity reaming.Before bone cement perfusion,2 ml of developing tracer was injected through the ear vein.Radionuclide imaging was performed at 60,120,and 180 minutes after bone cement perfusion,and the pulmonary radioactivity in vivo was measured.The rabbits were immediately sacrificed,and the pulmonary tissue was removed and its radioactivity was measured in vitro.Pulmonary tissue was then fixed and the pulmonary embolism and the associated pathological changes were observed.Results The pulmonary radioactivity in vivo was measured at 60,120,and 180 minutes after bone cement perfusion.The radioactivities of the four groups were 11.67±2.16,14.59±2.92 and 18.43±4.83 in group Ⅰ; 8.37±3.05,10.35±2.24 and 11.48±2.96 in group Ⅱ; 3.91±1.19,5.53±2

  14. Numerical predictions of the thermal behaviour and resultant effects of grouting cements while setting prosthetic components in bone.

    Science.gov (United States)

    Quarini, G L; Learmonth, I D; Gheduzzi, S

    2006-07-01

    Acrylic cements are commonly used to attach prosthetic components in joint replacement surgery. The cements set in short periods of time by a complex polymerization of initially liquid monomer compounds into solid structures with accompanying significant heat release. Two main problems arise from this form of fixation: the first is the potential damage caused by the temperature excursion, and the second is incomplete reaction leaving active monomer compounds, which can potentially be slowly released into the patient. This paper presents a numerical model predicting the temperature-time history in an idealized prosthetic-cement-bone system. Using polymerization kinetics equations from the literature, the degree of polymerization is predicted, which is found to be very dependent on the thermal history of the setting process. Using medical literature, predictions for the degree of thermal bone necrosis are also made. The model is used to identify the critical parameters controlling thermal and unreacted monomer distributions. PMID:16898219

  15. Percutaneous vertebroplasty in the treatment of vertebral body compression fracture with bone cement mixing and injection integrative system

    International Nuclear Information System (INIS)

    Objective: To evaluate the techniques and curative effects of percutaneous vertebroplasty (PVP) in vertebral compression fractures with bone cement mixing and injection integrative system. Methods: 108 patients with painful vertebral compression fractures (VCFs) were undergone PVP treatment in two years. There were 85 patients with osteoporotic VCFs and 31 patients with malignant VCFs. Polymethylmethacrylate (PMMA) were injected into the vertebral bodies via the bipedicular approach under fluoroscopic guidance with bone cement mixing and injection integrative system. Postvertebroplasty follow-up were achieved in six months. Results: Total 116 (100%) vertebral bodies (69 lumbar vertebrae and 47 thoracic vertebrae) were successfully injected with bone cement through bipedicular approach. Marked pain relief was achieved in 99 patients (91.7%). 95 patients (95.6%) had no pain reversion in the next six months. Only 9 patients (8.3%) had no pain relief. The extravasations of bone cement were observed in 12 patients (11%), with only 5(4.6%) had clinical symptoms. Conclusions: Percutaneous minimally vertebroplasty (PVP) is a minimally invasive and low complication method, with high efficacy for pain relief especially promising in the treatment of vertebral compression fractures. (authors)

  16. Antibacterial Efficacy of a New Gentamicin-Coating for Cementless Prostheses Compared to Gentamicin-Loaded Bone Cement

    NARCIS (Netherlands)

    Neut, Danielle; Dijkstra, Rene J. B.; Thompson, Jonathan I.; van der Mei, Henny C.; Busscher, Henk J.

    2011-01-01

    Cementless prostheses are increasingly popular but require alternative prophylactic measures than the use of antibiotic-loaded bone cements. Here, we determine the 24-h growth inhibition of gentamicin-releasing coatings from grit-blasted and porous-coated titanium alloys, and compare their antibacte

  17. A Stress Analysis on Abutment Teeth of Dowel Cemented Fixed Partial Dentures : On the effect of the resorption of alveoar bone

    OpenAIRE

    KATAOKA, SHIGERU; KOSAKA, SHIGERU; TSUCHIYA, SOHICHIRO; AMARI, MITSUHARU

    1995-01-01

    Stress in abutment teeth with cemented dowels and those with crown margins in fixed-fixed and cantilever bridges that resorp alveolar bone were analyzed by a two dimensional finite element method. Stress in all parts of the dentin in both bridges increased with the resorption of alveolar bone. Moreover, in th dentin and apex of the dowel in cantilever bridges, extreme stress when there were large amounts of resorption of alveolar bone, was seen. Therefore, in cantilevers bridges, cemented dow...

  18. An experimental study of domestic bone cement used on percutaneous vertebroplasty

    International Nuclear Information System (INIS)

    Objective: To evaluate the material properties of domestic bone cement (DBC) and imported bone cement (IBC) with different mixing ratio, and to determine whether the biomechanical properties of vertebral bodies (VBs) subjected to compression fractures and subsequently treated by vertebroplasty with DBC or IBC were different. Methods: There were two groups in this study. One was DBC, whose ratio of powder/liquid (g/ml) was 3:2 and the percentage of BaSO4 in powder was 20%, the other was IBC, whose mixing ratio followed manufacturer's recommendation. Polymerization time, strength, and stiffness of bone cement were measured respectively in each group. 20 lumbar VBs from four female cadavers (age, 75 ± 5 years) were disarticulated and compressed in a materials testing machine to determine initial strength and stiffness. The fractures were subsequently repaired using DBCor IBCon vertebroplasty. After augmentation, the VBs were scanned by CT, then recrushed, and stiffness and strength of VBs were measured again. Results: The stiffness of DBC whose mixing ratio was altered was (2711.8 ± 612.3) N/mm, while the stiffness of IBC was (2874.7 ± 457.6) N/mm, there was no significant differences between the two groups (t=0.609, P>0.05). But the strength of DBC (7271.3 ± 365.4) N was lower than that of IBC (8481.3 ± 397.3) N, (t=6.281, P0.05), while the strength of VBs augmentated with DBC and IBC were(1.226 ± 0.44) MPa and (1.202 ± 0.38) Mpa, respectively (F=0.001, P>0.05). CT value of DBC and IBC used on VBs were (2982.9 ± 102.0) Hu and (1554.3 ± 172.7) HU, respectively, and there was significant differences in radiopacity between them (t=22.525, P<0.05). Conclusion: DBC has an excellent radiopacity. VBs augmented by both DBC or IBC could attain satisfactory biomechanical properties, but these results have yet to be substantiated in clinical studies. (authors)

  19. Obtaining a pozzolanic addition from the controlled calcination of paper mill sludge. Performance in cement matrices

    Directory of Open Access Journals (Sweden)

    San José, J. T.

    2006-09-01

    Full Text Available Mineralogically, the paper mill sludge consists essentially of calcite, kaolinite, talc and other philosilicates (illite, chlorite. When such sludge is subjected to controlled thermal treatment, its kaolinite component may be transformed into metakaolin, yielding a product with high pozzolanic reactivity. This study was designed to analyze a number of scientific questions around the production of pozzolanic additions via controlled thermal activation of paper mill sludge and to evaluate the performance of such additions when included in a cement matrix. The findings show that paper mill waste activation is optimal when the sludge is calcined for 2 hours at 700 ºC in the 700-800 ºC interval. A comparative study between the cement made with the new addition and a commercial cement (CEM I-42.5R used as a reference led to highlight the scientific and technical viability of this waste as a cementing secondary material.Los lodos de destintado del papel están constituidos,mineralógicamente, por calcita, caolinita, talco y otros filosilicatos (ilita, clorita. Cuando al lodo se le somete aun tratamiento térmico controlado, la caolinita puede transformarse en metacaolín, dando origen a un producto de alta reactividad puzolánica.El objeto de este trabajo es analizar diferentes aspectos científicos relativos al proceso de obtención de una adiciónpuzolánica a partir de la activación térmica controlada de lodos de destintado del papel, así como evaluar el comportamiento de la nueva adición cuando se incorpora en una matriz de cemento. Los resultados obtenidos ponen de manifiesto la recomendación de utilizar 700 ºC durante 2 horas de permanencia en el horno, como condiciones más óptimas para activar los residuos de lodos de papel en el intervalo 700-800 ºC. Del estudio comparativo del cemento elaborado con la nueva adición con respecto a un cemento comercial (CEM I-42,5R, se puede destacar la viabilidad científica y técnica de

  20. Evaluation of damage progression and mechanical behavior under compression of bone cements containing core-shell nanoparticles by using acoustic emission technique.

    Science.gov (United States)

    Pacheco-Salazar, O F; Wakayama, Shuichi; Sakai, Takenobu; Cauich-Rodríguez, J V; Ríos-Soberanis, C R; Cervantes-Uc, J M

    2015-06-01

    In this work, the effect of the incorporation of core-shell particles on the fracture mechanisms of the acrylic bone cements by using acoustic emission (AE) technique during the quasi-static compression mechanical test was investigated. Core-shell particles were composed of a poly(butyl acrylate) (PBA) rubbery core and a methyl methacrylate/styrene copolymer (P(MMA-co-St)) outer glassy shell. Nanoparticles were prepared with different core-shell ratio (20/80, 30/70, 40/60 and 50/50) and were incorporated into the solid phase of bone cement at several percentages (5, 10 and 15 wt%). It was observed that the particles exhibited a spherical morphology averaging ca. 125 nm in diameter, and the dynamic mechanical analysis (DMA) thermograms revealed the desired structuring pattern of phases associated with core-shell structures. A fracture mechanism was proposed taking into account the detected AE signals and the scanning electron microscopy (SEM) micrographs. In this regard, core-shell nanoparticles can act as both additional nucleation sites for microcracks (and crazes) and to hinder the microcrack propagation acting as a barrier to its growth; this behavior was presented by all formulations. Cement samples containing 15 wt% of core-shell nanoparticles, either 40/60 or 50/50, were fractured at 40% deformation. This fact seems related to the coalescence of microcracks after they surround the agglomerates of core-shell nanoparticles to continue growing up. This work also demonstrated the potential of the AE technique to be used as an accurate and reliable detection tool for quasi-static compression test in acrylic bone cements. PMID:25792411

  1. Injectable citrate-modified Portland cement for use in vertebroplasty

    OpenAIRE

    Wynn-Jones, Gareth; Shelton, Richard M.; Hofmann, Michael P

    2014-01-01

    The injectability of Portland cement (PC) with several citrate additives was investigated for use in clinical applications such as vertebroplasty (stabilization of a fractured vertebra with bone cement) using a syringe. A 2-wt % addition of sodium or potassium citrate with PC significantly improved cement injectability, decreased cement setting times from over 2 h to below 25 min, while increasing the compressive strength to a maximum of 125 MPa. Zeta-potential measurements indicated that the...

  2. Effect of Additives on the Morphology of the Hydrated Product and Physical Properties of a Calcium Phosphate Cement

    Institute of Scientific and Technical Information of China (English)

    Xiupeng WANG; Jiandong YE; Yingjun WANG

    2008-01-01

    The morphology of a hydrated calcium phosphate cement (CPC) doped with several normally used additives was investigated by scanning electron microscopy (SEM) and the compressive strength of the cement was determined in this study. The hydrated products of CPC without additives was rod-like hydroxyapatite (HA) grains with around 2-5 μm in length and 100 nm in width. The addition of Sr obviously decreased the crystal size of the rod-like grains. CPCs containing carbonate, collagen and gelatin showed flake-like crystal morphology. Crylic acid-containing CPC presented flocculus-like structure. And malic acid-containing CPC exhibited oriented flake-like structure. The X-ray diffraction (XRD) analysis showed that the additives used in this study did not alter the hydration products of the cement. The compressive strength tests indicated that the compressive strength of the cement with rod-like morphology HA crystals was much higher than that of the cement with flake-like morphology HA crystals, and the cement with oriented flake-like morphology HA crystals .exhibited the poorest compressive strength.

  3. In vitro characterization and biomechanical optimization of a biodegradable particulate composite bone cement.

    Science.gov (United States)

    Gerhart, T N; Miller, R L; Kleshinski, S J; Hayes, W C

    1988-11-01

    We have developed a biodegradable particulate composite bone cement and used in vitro and in vivo methods for studying its suitability for orthopaedic applications. The composite matrix consists of gelatin, water, and sodium salicylate. The particulate phase is made up of powdered and particulate (355-600 microns diameter) tricalcium phosphate. Paraformaldehyde (0.1% to 0.5% by weight) is used as a matrix cross-linking agent. The effects of incubation time, particulate volume fraction, density of the individual particles, water content, concentration of crosslinking agent, and freeze-drying on the unconfined compressive strength and modulus of the particulate composite were measured. Compressive strengths of 7 MPa and moduli of 65 MPa could be achieved. Mechanical properties depended critically upon the water content of the particulate composite, with values of strength and modulus decreasing rapidly outside a range of 10-14% of specimen dry weight. High-density tricalcium phosphate particulate produced cement with twice the strength found with porous particulate. In a companion study we document in vivo performance of this particulate composite in an animal model system. PMID:3241009

  4. Effect of MgO Additive on Volumetric Expansion of Self-Degradable Cements

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Warren, J.; Butcher, T.

    2011-09-30

    We identified hard-burned magnesium oxide (MgO) as a suitable expansive additive for improving the plugging performance of self-degradable, temporary sodium silicate-activated slag/Class C fly ash (SSASC) blend cement sealers into rock fractures in Enhanced Geothermal Systems (EGSs). MgO extended the volumetric expansion of sealers during their exposure to a hydrothermal environment at 200 C under pressures, ranging from 300 to 1500 psi. A great expansion ratc of 19.3% was observed by adding 3.0 wt% MgO under 300 psi pressure, thus promising to plug thoroughly inner fracture. When the pressure was increased from 300 psi to 1500 psi, the expansion rate of cement markedly reduced, corresponding to the formaLion of crack-free specimens and the improvement of compressive strength. However, with 3.0 wt% MgO, the specimens still engendered the generation of numerous visual cracks, although they were prepared under a high pressure of 1500 psi. The effective content of MgO in minimizing and eliminating the generation of cracks was 2.0 wt%, which provided a moderate expansion of {ge} 0.5%. The compressive strength of 2.0 wt% MgO specimens made under a pressure of 300 psi rose {approx} 1.7-fold to 4816 psi with an increasing pressure to 1500 psi. The in-situ growth of brucite crystal formed by the hydrothermal hydration of MgO was responsive for such an expansion of the SSASC cement; meanwhile. two crystalline hydrothermal reaction products, 1.1 nm tobermorite and calcium silicate hydrated, contributed to the development of the sealer's compressive strength. Thus, the increasing pressure seems to suppress and control a growth rate of brucite crystal in response to a lower extension of expansion. Furthermore, all MgO-conlaining SSASC sealers possessed the water-catalyzed self-degradable properties.

  5. Mid-term study of bone remodeling after femoral cemented stem implantation: comparison between DXA and finite element simulation.

    Science.gov (United States)

    Herrera, Antonio; Rebollo, Sarai; Ibarz, Elena; Mateo, Jesús; Gabarre, Sergio; Gracia, Luis

    2014-01-01

    This five-year prospective study was designed to investigate periprosthetic bone remodeling associated with two cemented stem models, ABG-II (Stryker) and VerSys (Zimmer), randomly implanted in patients older than 75 years. The sample consisted of 64 cases (32, ABG-II; 32, VerSys). Inclusion criterion was diagnosis of osteoarthritis recommended for cemented total hip arthroplasty. Besides clinical study, Finite Element (FE) simulation was used to analyze biomechanical changes caused by hip arthroplasty. Bone Mineral Density (BMD) measurements showed a progressive increase in bone mass throughout the entire follow-up period for both stems, well correlated with FE results except in Gruen zones 4, 5, 6 for ABG-II and in zones 4, 5 for VerSys, denoting that remodeling in those zones does not depend on mechanical factors but rather on biological or physiological ones. PMID:23725926

  6. Improvement of bioactivity, degradability, and cytocompatibility of biocement by addition of mesoporous magnesium silicate into sodium-magnesium phosphate cement.

    Science.gov (United States)

    Wu, Yingyang; Tang, Xiaofeng; Chen, Jie; Tang, Tingting; Guo, Han; Tang, Songchao; Zhao, Liming; Ma, Xuhui; Hong, Hua; Wei, Jie

    2015-09-01

    A novel mesoporous magnesium-based cement (MBC) was fabricated by using the mixed powders of magnesium oxide, sodium dihydrogen phosphate, and mesoporous magnesium silicate (m-MS). The results indicate that the setting time and water absorption of the MBC increased as a function of increasing m-MS content, while compressive strength decreased. In addition, the degradability of the MBC in a solution of Tris-HCl and the ability of apatite formation on the MBC were significantly improved with the increase in m-MS content. In cell culture experiments, the results show that the attachment, proliferation, and alkaline phosphatase activity of the MC3T3-E1 cells on the MBC were significantly enhanced with the increase of the content of m-MS. It can be suggested that the MBC with good cytocompatibility could promote the proliferation and differentiation of the MC3T3-E1 cells. In short, our findings indicate that the MBC containing m-MS had promising potential as a new biocement for bone regeneration and repair applications. PMID:26395363

  7. Implementation of industrial waste ferrochrome slag in conventional and low cement castables: Effect of microsilica addition

    Directory of Open Access Journals (Sweden)

    Pattem Hemanth Kumar

    2014-06-01

    Samples with decreasing cement content 15–05 wt.% were formulated in combination of both slag and calcined bauxite as matrix components. Effects of varying 0–10 wt.% microsilica as a micro-fine additive in these castables were investigated in this work. Pore filling properties of microsilica improved apparent porosity and bulk density. Phase analysis through X-ray diffraction techniques demonstrates successful formation of spinel and mullite crystalline phases. Mechanical behavior was evaluated through cold crushing strength and residual cold crushing strength after five consecutive water quenching cycles. Scanning electron microscopy measurements were carried out in order to better understand the packing density and reaction mechanisms of fired castables. Slag containing castables portrays good thermal properties such as thermal shock resistance, permanent linear change and pyrometric cone equivalent.

  8. The Early Strength of Slag Cements with Addition of Hydrate Microcrystals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effect of hydrate microcrystals such as calcium silicate hydrates (CSH) and ettringite on the early strength of slag cements was studied.The authors explored the possibility of improving the early strength of the slag cement by applying crystal seed technology.It is shown that slag crystal seeds make the early strength of the cement increased due to the action of hydrate crystal seeds,which speed up the hydration of clinker minerals in the nucleation of ettringite.Therefore,the early strength of the slag cement is obviously improved.

  9. Preparation, characterization and investigation of in vitro and in vivo biological properties of strontium-modified calcium phosphate cement for bone defect repair

    Directory of Open Access Journals (Sweden)

    Reza Masaeli

    2015-12-01

    Full Text Available Background and Aims: The aim of this study was to evaluate the invitro and invivo performance of a 3 wt% of strontium additive hydroxyapatite calcium phosphate cements (CPC. Materials and Methods: The prepared calcium phosphate cement was characterized with XRD, FTIR, setting time, STA and in vitro and in vivo biological analyses. The MTT assay ALP activities as in vitro study and radiological and histological examinations as in vivo study between the three groups of 3 wt% Sr-HA/CPC, CPC and control were performed and compared. Data were analyzed using T-test and One-way ANOVA. Results: XRD analysis demonstrated that by increasing the ratio of Powder/Liquid (P/L, the crystallinity of the prepared cement increased. The substitution of strontium instead of calcium in CPC could also alter the crystal structure, including some structural disorder. However, in the CPC with no strontium hydroxyapatite (Sr-HA, no significant increase in the crystallinity was observed. SEM observations revealed CPC with increasing P/L ratio, the formation of hydroxyapatite crystals arising from the interaction of solid and liquid phase of cement was decreased. Also, the addition of Sr within Ca site culminated in a dramatic increase in crystallinity of hydroxyapatite. In vitro biological properties ascertained that addition of 3 wt. % Sr-HA into CPC enhanced MTT assay and ALP activity, which could be due to the presence of strontium ions. The histological study showed that greater remodeling was seen at 4 weeks after implantation when the 3 wt% Sr-HA/CPC was used. Conclusion: The obtained results cleared that CPC can be a potential candidate as a carrier with strontium additives for bone remodeling and regeneration.

  10. Biomechanical effects of bone cement volume on the endplates of augmented vertebral body: a three-dimensional finite element analysis

    Institute of Scientific and Technical Information of China (English)

    Yan Liang; Chang Zhen; Xu Zhengwei; Liu Tuanjiang; He Baorong; Hao Dingjun

    2014-01-01

    Background Previous studies have suggested that percutaneous vertebroplasty might alter vertebral stress transfer,leading to adjacent vertebral failure.However,no three-dimensional finite element study so far accounted for the stress distributions on different cement volumes.The purpose of this study was to evaluate the stress distributions on the endplate under different loading conditions after augmentation with various volumes of bone cement.Methods L2-L3 motion segment data were obtained from CT scans of the lumbar spine from a cadaver of a young man who had no abnormal findings on roentgenograms.Three-dimensional model of L2-L3 was established using Mimics software,and finite element model of L2-L3 functional spinal unit (FSU) was established using Ansys10.0 software.For simulating percutaneous vertebral augmentation,polymethylmethacrylate (PMMA) was deposited into the bipedicle of the L2 vertebra.The percentage of PMMA volume varied between 15% and 30%.The stress distributions on the endplate of the augmented vertebral body were calculated under three different loading conditions.Results In general,the stress level monotonically increased with bone cement volume.Under each loading condition,the stress change on the L2 superior and inferior endplates in three kinds of finite element models shows monotonic increase.Compared with the stress-increasing region of the endplate,the central part of the L2 endplate was subject to the greatest stress under three kinds of loading conditions,especially on the superior endplate and under flexion.Conclusions The finite element models of FSU are useful to optimize the planning for vertebroplasty.The bone cement volume might have an influence on the endplate of the augmentation,especially the superior endplate.It should be noted that the optimization of bone cement volume is patient specific; the volume of the bone cement should be based on the size,body mineral density,and stiffness of the vertebrae of individual

  11. Use of antibiotic cement-impregnated intramedullary nail in treatment of infected non-union of long bone

    Directory of Open Access Journals (Sweden)

    Shyam Ashok

    2009-01-01

    Full Text Available Background: In cases with infected non-union, the primary step is eradication of the infection before attempting to achieve union. Release of antibiotics from the bone cement at a high concentration and its penetration to the surrounding tissues, including cortical and cancellous bone, prompted the use of antibiotic cement in the control of bone infection. The aim of this study is to summarize our experience with the use of antibiotic cement-impregnated intramedullary nail (ACIIN for control of infection in cases of infected non-union with bone defect. Materials and Methods: We prospectively studied 25 cases of infected non-union (23 femora and two tibiae. There were 24 males and one female, with the mean age being 33 years (range, 21-58 years. All patients had high-velocity road traffic accidents except one patient who had farmland injury. There were seven closed fractures, one grade I compound, two grade II compound fractures, five grade IIIA compound fractures, and 10 grade IIIB compound fractures. ACIIN was used in all cases after adequate debridement. Patients were classified according to the amount of bone defect present after debridement: group 1 with bone defect < 4 cm (n=13, group 2 with bone defect ≥4-< 6 cm (n=7, and group 3 with bone defect ≥6 cm (n=5. Infection control was judged on the basis of discharge through the wound and laboratory parameters. All patients were followed-up, with an average follow-up time of 29 months (range, 18-40 months. The mean duration of retention of the intramedullary rod was 8 weeks (range, 6-12 weeks. Results: In group 1, all cases achieved infection control, with three patients achieving bone union without any need of secondary procedure. In group 2, all cases achieved infection control but the time taken was significantly longer than for group 1 (p-value 0.0002. All the cases required a secondary procedure in the form of either interlocking intramedullary nailing with iliac crest bone graft or

  12. Injectable calcium phosphate cement and fibrin sealant recombined human bone morphogenetic protein-2 composite in vertebroplasty: an animal study

    OpenAIRE

    Qian, Guang; Dong, Youhai; Yang, Wencheng; Wang, Minghai

    2012-01-01

    Polymethylmethacrylate (PMMA) is currently the most commonly-used material, but it may induce adjacent vertebral fracture due to low degradation and high strength. Our study evaluated the feasibility of injectable calcium phosphate cement (ICPC) and fibrin sealant (FS) as an injectable compound carrier of human bone morphogenetic protein-2 (rhBMP-2) in New Zealand rabbits for vertebroplasty. Results showed ICPC/FS/rhBMP-2 composites induced alkaline phosphatase most effectively at 2 and 4 wee...

  13. The effect of Al and Cr additions on pack cementation zinc coatings

    International Nuclear Information System (INIS)

    Zinc is widely used as a protective coating material due to its corrosion resistant properties. The structure and oxidation resistance of Al and Cr mixed zinc coatings, deposited by pack cementation process, is thoroughly examined in this work. The morphology and chemical composition of the as-deposited and oxidized samples was accomplished by electron microscopy while the phase identification was performed by XRD diffraction analysis. The experimental results showed that the addition of aluminum or chromium in the pack mixture forms only Al and Cr rich phases on the surface of the specimens without affecting significantly the phase composition of the rest zinc coatings. In the case of Zn-Al coatings, the overlying layer contains high concentrations of Al together with lower amounts of zinc and iron and in Zn-Cr coatings this layer contains Cr, Fe and Zn atoms and has much smaller thickness. The presence of these additional layers promotes significantly the oxidation resistance of the zinc pack coatings and they preserve most of their initial thickness and chemical content when exposed to an aggressive environment while their oxidation mass gain was measured at low levels during the oxidation tests.

  14. Effects of the addition of oil shale ash and coal ash on physic-chemical properties of CPJ45 cement

    Directory of Open Access Journals (Sweden)

    Nabih K.

    2014-04-01

    Full Text Available We focused our research on recycling industrial wastes, fly ash (F.A, bottom ash (B.A and oil shale ash (S.A in cement production. The study concerns physico-chemical characterization of these products and the influence of their addition on the mechanical proprieties of the CPJ45 cement. XRF allowed us to rank the three additives used according to their contents on major oxides. Coal ashes belong to the class F, and thus possess poozzolanic properties and oil shale ash belongs to the class C and possesses hydraulic and poozolanic properties. The crystalline phases constituting each ash were analysed by XRD. We observe in bottom ash the presence of quartz and mullite. The same crystals are found in fly ash with hematite and magnetite. Oil shale ash is composed of quartz, anhydrite, gehlenite, wollastonite and periclase. The microstructures of fly ash and bottom ash were studied using SEM. The bottom ash was composed respectively of fine particles that are generally irregularly shaped, their dimensions are between 5 and 28μm and of big particles(300 μm. The EDX analysis coupled with an electronic microscope provided some information about the major elements that constitute our samples. The dehydrations of anhydrous and three days hydrated cement were examined by DSC. For hydrated cements we noticed endothermic peaks related to the dehydration of CSH, CH and decomposition of carbonates. The study of the mechanical properties of CPJ45 cement by adding different proportions of fly ash, bottom ash and oil shale ash helped clarifying the percentage of ash that leaded to improve the 28 days mechanical strength. The results show that the cements studied have their maximum mechanical resistance with the addition at 7% of fly ash or 10% of oil shale ash.

  15. Microstructure, characterizations, functionality and compressive strength of cement-based materials using zinc oxide nanoparticles as an additive

    International Nuclear Information System (INIS)

    Highlights: • Nano zinc oxide was used as an additive material. • Microstructure and phase characterization of pastes were characterized using SEM and XRD. • TGA and FTIR were also used to determine the hydration reaction. • Compressive strength of ZnO mixes was found to increase at 28 days. - Abstract: Zinc oxide nanoparticles as a nanophotocatalyst has great potential for self-cleaning applications in concrete structures, its effects on the cement hydration, setting time and compressive strength are also important when using it in practice. This paper reports the effects of zinc oxide nanoparticles, as an additive material, on properties of cement-based materials. Setting time, compressive strength and porosity of mortars were investigated. Microstructure and morphology of pastes were characterized using scanning electron microscope and X-ray diffraction (XRD), respectively. Moreover, thermal gravimetric analysis (TGA) and Fourier-transform infrared spectrometer (FTIR) were also used to determine the hydration reaction. The results show that Portland cement paste with additional ZnO was found to slightly increase the water requirement while the setting time presented prolongation period than the control mix. However, compressive strength of ZnO mixes was found to be higher than that of PC mix up to 15% (at 28 days) via filler effect. Microstructure, XRD and TGA results of ZnO pastes show less hydration products before 28 days but similar at 28 days. In addition, FTIR results confirmed the retardation when ZnO was partially added in Portland cement pastes

  16. Improved cement mortars by addition of carbonated fly ash from solid waste incinerators

    Directory of Open Access Journals (Sweden)

    López-Zaldívar, O.

    2015-09-01

    Full Text Available This article presents the results of a research developing high performance cement mortars with the addition of municipal solid waste incineration fly ash (MSWIFA stabilized as insoluble carbonates. The encapsulation of hazardous wastes in mortar matrixes has also been achieved. The ashes present high concentrations of chlorides, Zn and Pb. A stabilization process with NaHCO3 has been developed reducing 99% the content of chlorides. Developed mortars replace 10% per weight of the aggregates by treated MSWIFA. Physical/mechanical properties of these mortars have been studied. Presence of Zn, Pb, Cu and Cd has been also analyzed confirming that leaching of these heavy metal ions is mitigated. Conclusions prove better behavior of CAC and CSA mortars than those of CEM-I and CEM-II cement. Results are remarkable for the CAC mortars, improving reference strengths in more than 25%, which make them a fast-curing product suitable for the repair of structures or industrial pavements.Este artículo presenta los resultados del desarrollo de morteros mejorados con la incorporación de cenizas volantes de residuos sólidos urbanos inertizadas en forma de carbonatos. Además se consigue la encapsulación de un residuo peligroso. Las cenizas presentan una alta concentración de cloruros, Zn y Pb. Se ha desarrollado un proceso de estabilización con NaHCO3 reduciendo en un 99% el contenido de cloruros. Los morteros reemplazan un 10% en peso del árido por cenizas tratadas. Se han analizado sus propiedades físico/mecánicas y la presencia de Zn, Pb, Cu y Cd. Se demuestra un mejor comportamiento de los morteros de CAC y CSA que los de CEM-I y CEM-II y se mitiga el lixiviado de metales pesados. Los resultados son significativos en los morteros CAC al mejorar las resistencias de los de referencia en un 25%. Los morteros desarrollados son de curado rápido adecuados para la reparación de estructuras o soleras industriales.

  17. Effect of additives on the compressive strength and setting time of a Portland cement

    Directory of Open Access Journals (Sweden)

    Desirée Freitas Mryczka Machado

    2010-06-01

    Full Text Available Improvements in strength and setting time of Portland cements (PC are needed to enhance their performance as endodontic and load bearing materials. This study sought to enhance the compressive strength and setting time of a PC by adding one of the following additives: 20% and 30% poly-methylmethacrylate (PMMA, 20% and 30% irregular and spherical amalgam alloys, and 10% CaCl2. The control consisted of unreinforced PC specimens. Setting time was determined using a Gillmore apparatus according to standardized methods while compressive strength was measured using a universal testing machine after 21 hours or 60 days of water storage. Data were analyzed by ANOVA, Tukey and Games-Howell tests (α = 5%. All additives significantly decreased both initial and final setting times as compared with the PC-control (p < .05. 30% PMMA and 30% irregular alloy had the lowest values of initial setting time. 30% irregular alloy also produced the lowest values of final setting time while 30% spherical alloy yielded the highest (p < .05. No differences were detected between the compressive strength values of 21 hours and 60 days. While 10% CaCl2, 20% and 30% PMMA produced values significantly lower than the PC-control, 30% spherical alloy significantly improved the compressive strength of the reinforced PC (p < .05. In summary, all additives significantly reduced the setting time and 30% spherical amalgam alloy yielded a significant increase in compressive strength for the tested PC, which might represent an improved composition for PCs to expand their use as endodontic and potentially load bearing materials.

  18. Physical and mechanical characterization of Portland cement mortars made with expanded polystyrene particles addition (EPS

    Directory of Open Access Journals (Sweden)

    Ferrándiz-Mas, V.

    2012-12-01

    Full Text Available On this work the influence of the addition of different types (commercial and recycled and contents of expanded polystyrene on the physical and mechanical properties of Portland cement mortars has been studied. Variables studied are: workability, air content, bulk density, mechanical strength, porosity, water absorption and sound absorption. Mixtures have been also characterized by scanning electron microscopy. Air-entraining agents, water retainer and superplasticizer additives have been used in order to improve the workability of mortars. The results show that the workability and mechanical strength decreases with increasing content of expanded polystyrene. Additives improve the workability and porosity, allowing manufacture mortars with high levels of recycled material that show mechanical properties suitable for use as masonry mortars, stucco and plaster.

    El objetivo de este estudio es evaluar la influencia de la adición de distintos tipos y dosificaciones de poliestireno expandido, tanto comerciales como procedentes de reciclado, sobre las características físicas y mecánicas de morteros de cemento portland. Las variables estudiadas fueron: consistencia, aire ocluido, densidad aparente, resistencias mecánicas, porosidad, absorción de agua y absorción acústica. Los morteros también se han caracterizado por microscopia electrónica de barrido. Con objeto de mejorar la trabajabilidad de los morteros se ha empleado aditivos aireante, retenedor de agua y fluidificante. Los resultados muestran que al aumentar la cantidad de poliestireno expandido la trabajabilidad y las resistencias mecánicas disminuyen. El empleo de aditivos mejora la trabajabilidad y la porosidad, permitiendo fabricar morteros con altos contenidos de residuo, con propiedades mecánicas adecuadas para su empleo como morteros de albañilería, revoco y enlucido.

  19. Sustainable production of blended cement in Pakistan through addition of natural pozzolana

    OpenAIRE

    Ahmad Muhammad Imran; Sajjad Muhammad; Khan Irfan Ahmed; Durrani Amina; Durrani Ali Ahmed; Gul Saeed; Ullah Asmat

    2016-01-01

    In this work pozzolana deposits of district Swabi, Pakistan were investigated for partial substitution of Portland cement along with limestone filler. The cement samples were mixed in different proportions and tested for compressive strength at 7 and 28 days. The strength activity index (SAI) for 10 % pozzolana, and 5% limestone blend at 7 and 28 days was 75.5% and 85.0% satisfying the minimum SAI limit of ASTM C618. Twenty two percents natural pozzolana an...

  20. Effect of Additives and pH on the Formation of Carbonate Mineral by CO2 Sequestration of Cement Paste

    Science.gov (United States)

    Lee, J. H.; Hwang, J.; Lee, H.; Son, B. S.; Oh, J.

    2015-12-01

    CO2 in the atmosphere causes a global warming that is a big issue nowadays. Many studies of CO2 capture and storage (CCS) technologies have been studied all over the world. Waste cement is a good source for aqueous carbonation because it is rich in calcium. Therefore, this study was performed to develop the aqueous carbonation method for waste cement powder. Cement paste was made with water/cement ratio of 6:4 and cured for 28 days in water bath. The cement paste was pulverized into a fine powder sizing less than 0.15 mm. To study effect of additives and pH on the formation of carbonate minerals, aqueous carbonation experiments were conducted. The mineral compositions and morphology of carbonate mineral were identified by XRD and SEM/EDS analysis. 1.0 M NaCl and 0.25 M MgCl2 were applied as additives. Aqueous carbonation experiment was conducted with injecting pure CO2 gas (99.9%) to a reactor containing 200 ㎖ of reacting solution. The pH of reacting solution was controled to determine formational condition of carbonate minerals. In 0.25 M MgCl2 solution, calcite was dominant mineral at high pH. More aragonite, however, formed as decreasing pH of solution with injection of CO2. The presence of Mg2+ in solution makes aragonite more dominant than calcite. Aragonite was mainly formed at the high pH of solution with 1.0 M NaCl additive, whereas calcite was more preponderant mineral than aragonite as falling pH. It show that unstable aragonite transformed to calcite as decreasing pH. In no additive solution, vaterite was dominantly formed at the initial stage of experiement, but unstable vaterite transformed to well crystallized calcite with further carbonation.

  1. Concrete Durability Properties and Microstructural Analysis of Cement Pastes with Nopal Cactus Mucilage as a Natural Additive

    Directory of Open Access Journals (Sweden)

    Ramírez-Arellanes, S.

    2012-09-01

    Full Text Available The present study evaluated the addition of a 3% nopal cactus mucilage solution to cement pastes, in its effects on setting times, flow, hydration, and microstructure, as well as on capillary water absorption and chloride diffusion in concrete. Hydration was characterized through XRD and microstructure was characterized with SEM. The mucilage solution/cement and water/cement ratios tested were 0.30, 0.45, and 0.60. The results in cement pastes indicate that the addition of mucilage increases setting times, reduces flow, slows cement hydration, and inhibits the formation of calcium hydroxide crystals in comparison with the control. Capillary absorption was significantly reduced in concrete containing mucilage, and chloride diffusion coefficients dropped up to 20% in the mixture with a mucilage/cement ratio = 0.30. The mixture with a mucilage/cement ratio = 0.45 displayed marginal reduction, and the mixture with mucilage/cement ratio = 0.60 exhibited a diffusion coefficient that was greater than the control for the specimens without moist curing.En esta investigación se evaluó el efecto de una solución de mucílago de nopal al 3% en los tiempos de fraguado, fluidez, hidratación y microestructura de pastas de cemento, y absorción capilar de agua y difusión de cloruros en concreto. La hidratación fue caracterizada por XRD y la microestructura por medio de SEM. Las relaciones solución de mucílago/cemento y agua/cemento fueron 0,30; 0,45 y 0,60. Los resultados en las pastas de cemento indican que el mucílago retarda los tiempos de fraguado, reduce la fluidez, retarda la hidratación del cemento, e inhibe la formación de cristales de hidróxido de calcio, comparados con los controles. La absorción capilar en concreto conteniendo mucílago se redujo significativamente y los coeficientes de difusión de cloruros disminuyeron hasta 20% en la mezcla mucílago/cemento = 0.30. En la relación mucílago/cemento = 0.45 la reducción fue marginal y

  2. Adhesive strength of total knee endoprostheses to bone cement - analysis of metallic and ceramic femoral components under worst-case conditions.

    Science.gov (United States)

    Bergschmidt, Philipp; Dammer, Rebecca; Zietz, Carmen; Finze, Susanne; Mittelmeier, Wolfram; Bader, Rainer

    2016-06-01

    Evaluation of the adhesive strength of femoral components to the bone cement is a relevant parameter for predicting implant safety. In the present experimental study, three types of cemented femoral components (metallic, ceramic and silica/silane-layered ceramic) of the bicondylar Multigen Plus knee system, implanted on composite femora were analysed. A pull-off test with the femoral components was performed after different load and several cementing conditions (four groups and n=3 components of each metallic, ceramic and silica/silane-layered ceramic in each group). Pull-off forces were comparable for the metallic and the silica/silane-layered ceramic femoral components (mean 4769 N and 4298 N) under standard test condition, whereas uncoated ceramic femoral components showed reduced pull-off forces (mean 2322 N). Loading under worst-case conditions led to decreased adhesive strength by loosening of the interface implant and bone cement using uncoated metallic and ceramic femoral components, respectively. Silica/silane-coated ceramic components were stably fixed even under worst-case conditions. Loading under high flexion angles can induce interfacial tensile stress, which could promote early implant loosening. In conclusion, a silica/silane-coating layer on the femoral component increased their adhesive strength to bone cement. Thicker cement mantles (>2 mm) reduce adhesive strength of the femoral component and can increase the risk of cement break-off. PMID:25781660

  3. Effect of blastfurnace slag addition to Portland cement for cationic exchange resins encapsulation

    Directory of Open Access Journals (Sweden)

    Stefan L.

    2013-07-01

    Full Text Available In the nuclear industry, cement-based materials are extensively used to encapsulate spent ion exchange resins (IERs before their final disposal in a repository. It is well known that the cement has to be carefully selected to prevent any deleterious expansion of the solidified waste form, but the reasons for this possible expansion are not clearly established. This work aims at filling the gap. The swelling pressure of IERs is first investigated as a function of ions exchange and ionic strength. It is shown that pressures of a few tenths of MPa can be produced by decreases in the ionic strength of the bulk solution, or by ion exchanges (2Na+ instead of Ca2+, Na+ instead of K+. Then, the chemical evolution of cationic resins initially in the Na+ form is characterized in CEM I (Portland cement and CEM III (Portland cement + blastfurnace slag cements at early age and an explanation is proposed for the better stability of CEM III material.

  4. Influence of Geosta Addition on Cement-stabilised Chicoco Mud of the Niger Delta

    Directory of Open Access Journals (Sweden)

    Olujide Omotosho

    2005-01-01

    Full Text Available Chicoco is a very soft and extremely compressible organic marine mud found extensively and to considerable depths within the saline tidal flat or mangrove swamp of the Niger delta in southern Nigeria. Natural chicoco is highly undesirable, barely able to support a human of average weight but air-dried chicoco has been used successfully by the indigeneous people for shore protection, etc. especially if placed above water. Plain cement stabilization of most organic soils (including chicoco is known to be ineffective. In this study, geosta, a chemical stabiliser relatively newly developed for organic soils was combined with ordinary Portland cement to stabilise chicoco. It was observed that neutralisation of acidic "air-dried" chicoco by basic geosta inhibited the expected ion-exchange reaction and its attendant improvement on mechanical properties. As a result and as geosta content increases, maximum dry density (MDD was found to be only marginally improved but better for higher cement contents while optimum moisture content (OMC decreases but with higher values for lower cement contents. Unsoaked CBR (but with samples wax-cured for 3 days on the other hand was found to maximise at low geosta content and thereafter decreases continually - a major cost advantage in earthworks. In fact, the most effective influence was obtained at 4.0% cement plus about 1.5% geosta. This stabilization was also found to produce optimum road sub-base materials.

  5. Development of hydroxyapatite bone cement for controlled drug release via tetracycline hydrochloride

    Indian Academy of Sciences (India)

    Sayed Mahmood Rabiee

    2013-02-01

    The purpose of this work was to study the preparation and characterization of drug–hydroxyapatite cement. The hydroxyapatite (HA) cement has been synthesized by using tricalcium phosphate, calcium carbonate and dicalcium phosphate anhydrous with sodium hydrogen phosphate as liquid phase. The effect of added tetracycline hydrochloride (TCH) as drug on final phases, microstructure, setting behaviour and compressive strength has been studied. The drug release rate was first order within the first day and then was zero order. No obvious difference could be detected in XRD patterns of the TCH–HA cement with various amounts of drug. By increasing the drug concentration, mechanical strength of cement was decreased and its setting time was increased. The results of this study demonstrate the potential of using HA cement as a carrier for drug delivery.

  6. A nonlinear inverse problem in estimating the polymerization heat source of bone cements by an iterative regularization method

    International Nuclear Information System (INIS)

    In the present study, the conjugate gradient method (CGM) using an iterative regularization method (IRM) is used to solve the inverse heat conduction problem (IHCP) in order to estimate the unknown heat generated during polymerization of bone cement. The exothermic chain propagation reaction results in a high local temperature and has a deleterious effect on living tissues and extracellular matrices. Only when such a heat source is estimated accurately, can the influences of the production of bone cements on bone cells be analyzed more clearly. Results obtained by using the CGM to solve this IHCP are justified based on the numerical experiments. It is concluded based on the results of the reported numerical experiments that the accurate polymerization heat source can be estimated by the CGM. Finally, the effects of the simulated measurement errors on the inverse solutions are included and discussed. It is found that when considering a real functional form of heat source, the measurement errors of 1% and 3% will yield the relative average errors for the solution of only less than 2% and 4%, respectively

  7. Characteristics and propierties of oil-well cements additioned with blast furnace slag

    Directory of Open Access Journals (Sweden)

    Sánchez, R.

    2011-06-01

    Full Text Available The present paper addresses the alkali activation of Portland cements containing blast furnace slag (20 and 30% of the cement by weight with a view to the possible use of these materials in oil well construction. The hydration studies conducted showed that in cement/slag blends, the sodium silicate activating solution partially inhibited the dissolution of the silicate phases in the Portland cement, retarding cement hydration and reducing the precipitation of reaction products. Due to such partial inhibition, the cement/slag blends had significantly lower mechanical strength than Portland cements hydrated with water. 29Si and 27Al MAS NMR and BSE/EDX studies, in turn, showed that the C-S-H gel forming in the alkali-activated cement/slag pastes contained Al in tetrahedral positions and low Ca/Si ratios.

    En el presente trabajo se ha estudiado la activación alcalina de cementos Pórtland con incorporación de escoria de horno alto (20% y 30% con respecto al peso de cemento para su posible aplicación en la construcción de pozos petrolíferos. Los estudios de hidratación realizados indican que en mezclas cemento/escoria, la disolución activadora de silicato sódico inhibe parcialmente la disolución de las fases silicato del cemento Pórtland originando un retraso de su hidratación así como la menor precipitación de productos de reacción. Dicha parcial inhibición de los procesos reactivos en las mezclas cemento/escoria originan resistencias mecánicas significativamente inferiores a las pastas de cemento Portland hidratadas con agua. Finalmente, los estudios de 29Si y 27Al RMN MAS y BSE/EDX indican que el gel C-S-H formado en pastas de mezcla cemento/escoria activadas alcalinamente presenta Al en posiciones tetraédricas y bajas relaciones Ca/Si.

  8. Regulation of physicochemical properties, osteogenesis activity, and fibroblast growth factor-2 release ability of β-tricalcium phosphate for bone cement by calcium silicate

    Energy Technology Data Exchange (ETDEWEB)

    Su, Ching-Chuan [Antai Medical Care Cooperation Antai Tian-Sheng Memorial Hospital, Pingtung, Taiwan (China); Kao, Chia-Tze; Hung, Chi-Jr [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Chen, Yi-Jyun [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Dental Department, Taichung Hospital, Ministry of Health and Welfare, Taichung City, Taiwan (China); Huang, Tsui-Hsien, E-mail: thh@csmu.edu.tw [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [Institute of Oral Science, Chung Shan Medical University, Taichung, Taiwan (China)

    2014-04-01

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of bone-like apatite, the diametral tensile strength, and weight loss of composites were considered before and after immersion in simulated body fluid (SBF). In addition, we also examined the effects of fibroblast growth factor-2 (FGF-2) released from β-TCP/CS composites and in vitro human dental pulp cell (hDPC) and studied its behavior. The results showed that the apatite deposition ability of the β-TCP/CS composites was enhanced as the CS content was increased. For composites with more than 50% CS contents, the samples were completely covered by a dense bone-like apatite layer. At the end of the immersion point, weight losses of 19%, 24%, 33%, 42%, and 51% were observed for the composites containing 0%, 30%, 50%, 70% and 100% β-TCP cements, respectively. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 70%, the amount of cells and osteogenesis protein of hDPCs was stimulated by FGF-2 released from β-TCP/CS composites. The combination of FGF-2 in degradation of β-TCP and osteogenesis of CS gives a strong reason to believe that these calcium-based composite cements may prove to be promising bone repair materials. - Highlights: • CS improved physicochemical properties and osteogenic activity of β-TCP. • The higher the CS in the cement, the shorter the setting time and the higher the DTS. • The cell behavior was stimulated by FGF-2 released from composite containing 50% CS. • β-TCP/CS composite with FGF-2 has optimal properties for

  9. Regulation of physicochemical properties, osteogenesis activity, and fibroblast growth factor-2 release ability of β-tricalcium phosphate for bone cement by calcium silicate

    International Nuclear Information System (INIS)

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of bone-like apatite, the diametral tensile strength, and weight loss of composites were considered before and after immersion in simulated body fluid (SBF). In addition, we also examined the effects of fibroblast growth factor-2 (FGF-2) released from β-TCP/CS composites and in vitro human dental pulp cell (hDPC) and studied its behavior. The results showed that the apatite deposition ability of the β-TCP/CS composites was enhanced as the CS content was increased. For composites with more than 50% CS contents, the samples were completely covered by a dense bone-like apatite layer. At the end of the immersion point, weight losses of 19%, 24%, 33%, 42%, and 51% were observed for the composites containing 0%, 30%, 50%, 70% and 100% β-TCP cements, respectively. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 70%, the amount of cells and osteogenesis protein of hDPCs was stimulated by FGF-2 released from β-TCP/CS composites. The combination of FGF-2 in degradation of β-TCP and osteogenesis of CS gives a strong reason to believe that these calcium-based composite cements may prove to be promising bone repair materials. - Highlights: • CS improved physicochemical properties and osteogenic activity of β-TCP. • The higher the CS in the cement, the shorter the setting time and the higher the DTS. • The cell behavior was stimulated by FGF-2 released from composite containing 50% CS. • β-TCP/CS composite with FGF-2 has optimal properties for

  10. Modification of Baksi sloppy hinge elbow to minimize the stresses at the humeral bone cement interface- An early experience

    Directory of Open Access Journals (Sweden)

    Baksi D

    2005-01-01

    Full Text Available Background : Baksi sloppy hinge elbow is an all metal prosthesis having 7 0 - 10 0 varus - valgus inherent laxity at the hinge section with minimal motion bearing contact area. Due to the presence of laxity at it′s hinge section, any strain on the prosthesis dissipates primarily to the surrounding soft tissues thus protecting the cement bone interfaces. However, from our long term clinical experiences on the use of our sloppy hinge design since 1984 and the knowledge of literature review of the results of using other semi-constrained (sloppy or unconstrained designs, it was observed that radiolucency or loosening at the bone-cement interface occurred mainly around the humeral stem in the long run due to the continued effect of rotational torque of forearm and hand. Hence, an attempt in the improvement of the design concept is being made. Methods : In this respect one flange each of one cm height and breadth and three mm thickness has been incorporated on either sides of the shank of humeral stem of the sloppy hinge at medio-lateral (coronal plane which will be seated in the corresponding longitudinal groove cut on either side of humeral shaft extending from its transverse cut end to become single assembly during the rotation of humerus. Results : The preliminary results of clinical application of the modified sloppy hinge elbow in ten cases are found satisfactory. Conclusion : The cyclical compression and distraction forces during flexion and extension of the elbow will be distributed over the larger bony area of lower end of humerus where flanges of the humeral shank being seated. The rotational torque effect of forearm and hand particularly with the arm in abduction will be minimised at the humeral bone cement interface as the humerus and the prosthetic stem act as a single assembly by the snugly fitting of the prosthetic flange in the humural shaft

  11. In situ synchrotron X-ray powder diffraction study of the early hydration of α-tricalcium phosphate/tricalcium silicate composite bone cement

    International Nuclear Information System (INIS)

    Bioactivity, osteogenicity and mechanical properties of α-tricalcium phosphate (α-TCP) based phosphates cements can be improved by adding tricalcium silicate (C3S); however, the addition of C3S delays the precipitation and growth of calcium deficient hydroxyapatite (CDHA). Thus, the aim of this work was the study of in situ setting reaction of α-TCP/C3S composite bone cement under high energy X-ray generated by a synchrotron source within the first 72h. The results showed that the addition of C3S induces the precipitation of nanosized CDHA at early times depending on the added content. Calculated crystallite sizes showed that the higher the content of C3S, the smaller the crystal size at the beginning of the precipitation. These results are different from those obtained by conventional XRD method, suggesting that the proposed technique is a powerful tool in determining the composition and extent of reaction of CPCs surfaces in real time. (author)

  12. In situ synchrotron X-ray powder diffraction study of the early hydration of α-tricalcium phosphate/tricalcium silicate composite bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Morejon-Alonso, Loreley; Correa, Jose Raul, E-mail: lmorejon@fq.uh.cu [Departamento de Quimica General, Facultad de Quimica, Universidad de La Habana, UH (Cuba); Motisuke, Mariana [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil); Carrodeguas, Raul Garcia [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Laboratorio de Avaliacao e Desenvolvimento de Biomateriais do Nordeste; Santos, Luis Alberto dos [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Escola de Engenharia. Departamento de Materiais

    2015-01-15

    Bioactivity, osteogenicity and mechanical properties of α-tricalcium phosphate (α-TCP) based phosphates cements can be improved by adding tricalcium silicate (C{sub 3}S); however, the addition of C{sub 3}S delays the precipitation and growth of calcium deficient hydroxyapatite (CDHA). Thus, the aim of this work was the study of in situ setting reaction of α-TCP/C{sub 3}S composite bone cement under high energy X-ray generated by a synchrotron source within the first 72h. The results showed that the addition of C{sub 3}S induces the precipitation of nanosized CDHA at early times depending on the added content. Calculated crystallite sizes showed that the higher the content of C{sub 3}S, the smaller the crystal size at the beginning of the precipitation. These results are different from those obtained by conventional XRD method, suggesting that the proposed technique is a powerful tool in determining the composition and extent of reaction of CPCs surfaces in real time. (author)

  13. Comparison of sealing ability of bioactive bone cement, mineral trioxide aggregate and Super EBA as furcation repair materials: A dye extraction study

    Directory of Open Access Journals (Sweden)

    Janani Balachandran

    2013-01-01

    Settings and Design: In vitro, dye extraction study. Materials and Methods: Forty mandibular molars were randomly divided according to the material used to repair perforation: Group I-MTA, Group II-bioactive bone cement, Group III-Super EBA, Group IV-Control (furcation left unrepaired. All samples were subject to ortho grade and retrograde methylene blue dye challenge followed by dye extraction with 65% nitric acid. Samples were then analyzed using Ultra violet (UV Visible Spectrophotometer. Statistical Analysis Used: One way analysis of variance (ANOVA, Tukey-Kramer Multiple Comparisons Test. Results: MTA and bioactive bone cement showed almost similar and lower absorbance values in comparison to Super EBA. Conclusions: Bioactive bone cement provi ded an excellent seal for furcal perforation repair and at the same time it provided comfortable handling properties, which could overcome the potential disadvantages as faced with MTA.

  14. In vitro assessment of Function Graded (FG artificial Hip joint stem in terms of bone/cement stresses: 3D Finite Element (FE study

    Directory of Open Access Journals (Sweden)

    Al-Jassir Fawzi F

    2013-01-01

    Full Text Available Abstract Background Stress shielding in the cemented hip prosthesis occurs due to the mismatching in the mechanical properties of metallic stem and bone. This mismatching in properties is considered as one of the main reasons for implant loosening. Therefore, a new stem material in orthopedic surgery is still required. In the present study, 3D finite element modeling is used for evaluating the artificial hip joint stem that is made of Function Graded (FG material in terms of joint stress distributions and stem length. Method 3D finite element models of different stems made of two types of FG materials and traditional stems made of Cobalt Chromium alloy (CoCrMo and Titanium alloy (Ti were developed using the ANSYS Code. The effects on the total artificial hip joint stresses (Shear stress and Von Mises stresses at bone cement, Von Mises stresses at bone and stem due to using the proposed FG materials stems were investigated. The effects on the total artificial hip joint system stresses due to using different stem lengths were investigated. Results Using FG stem (with low stiffness at stem distal end and high stiffness at its proximal end resulted in a significant reduction in shear stress at the bone cement/stem interface. Also, the Von Mises stresses at the bone cement and stem decrease significantly when using FG material instead of CoCrMo and Ti alloy. The stresses’ distribution along the bone cement length when using FG material was found to be more uniform along the whole bone cement compared with other stem materials. These more uniform stresses will help in the reduction of the artificial hip joint loosening rate and improve its short and long term performance. Conclusion FE results showed that using FG stem increases the resultant stresses at the femur bone (reduces stress shielding compared to metallic stem. The results showed that the stem length has significant effects on the resultant shear and Von Mises stresses at bone, stem and

  15. The mechanical and biological studies of calcium phosphate cement-fibrin glue for bone reconstruction of rabbit femoral defects

    Directory of Open Access Journals (Sweden)

    Dong J

    2013-03-01

    Full Text Available Jingjing Dong,1,* Geng Cui,2,* Long Bi,1,* Jie Li,3 Wei Lei11Institute of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China; 2Institute of Orthopedics, General Hospital of PLA, Beijing, People’s Republic of China; 3Institute of Gynecology and Obstetrics, General Hospital of PLA, Beijing, People’s Republic of China*These authors contributed equally to this workAbstract: In order to improve the mechanical and biological properties of calcium phosphate cement (CPC, nanometer-biomaterial for bone reconstruction in the rabbit femoral defect model, fibrin glue (FG, the natural product, purified from the blood was introduced at three different ratios. The CPC powder and the FG solution were mixed, respectively, at the powder/liquid (P/L ratios (g/mL of 1:1, 3:1, and 5:1 (g/mL, and pure CPC was used as a control. After being implanted into the femoral defect in rabbit, the healing process was evaluated by micro-computed tomography scan, biomechanical testing, and histological examination. By micro-computed tomography analysis, the P/L ratio of 1:1 (g/mL group indicated the largest quantity of new bone formation at 4 weeks, 8 weeks, and 12 weeks after implantation, respectively. Bone volume per trabecular volume of the 1:1 group was highest in the four groups, which was 1.45% ± 0.42%, 7.35% ± 1.45%, and 29.10% ± 1.67% at 4 weeks, 8 weeks, and 12 weeks after the operation, respectively. In the biomechanical tests, the compressive strength and the elastic modulus of the three CPC–FG groups were much higher than those of the pure CPC group at the determined time point (P < 0.05. The histological evaluation also showed the best osseointegration in the 1:1 group at 4 weeks, 8 weeks, and 12 weeks after the operation, respectively. In the 1:1 group, the bone grew into the pore of the cement in the laminar arrangement and connected with the cement tightly at the 12th week after the operation

  16. Influence of addition of calcium oxide on physicochemical properties of Portland cement with zirconium or niobium oxide

    Directory of Open Access Journals (Sweden)

    Mario Tanomaru-Filho

    2015-01-01

    Full Text Available Context: Calcium oxide (CaO may be added to mineral trioxide aggregate (MTA or Portland cement (PC to improve physicochemical and biological properties. Aims: To evaluate the physicochemical properties of PC associated with radiopacifiers and CaO. Materials and Methods: MTA Angelus, PC + 30% zirconium oxide (Zr, or 30% niobium oxide (Nb associated with 10 or 20% of CaO were evaluated. Gilmore needles were used to evaluate initial and final setting time. Compressive strength was evaluated after the periods of 24 hours and 21 days. pH was analyzed after 3, 12, 24 hours, 7, 14, 21 days. Solubility and flow tests were performed based on the ISO 6876. The data obtained were submitted to analysis of variance and Tukey tests (P ≤ 0.05. Results: The associations with 10% CaO showed greater strength that the associations with 20% CaO. The shortest initial setting time was observed for the association PC + Zr + 20% CaO and MTA. All the cements presented alkaline pH. The flow of all cements was similar. The highest solubility was found in the associations with 20% CaO. Conclusion: The addition of CaO to PC favored the alkaline property and the PC + Zr + 20% CaO presented setting time similar to MTA.

  17. 骨水泥强化椎弓根螺钉固定对骨质疏松患者有利无弊?★%Pedicle screw fixation augmented with bone cement benefits osteoporosis patients?

    Institute of Scientific and Technical Information of China (English)

    岳文峰; 夏虹; 王建华

    2013-01-01

    BACKGROUND:During the pedicle screw fixation for lumbar disease patients accompanied with osteoporosis, addition of bone cement in osteoporotic vertebral body can significantly increase the stability of internal fixation, but the effect on adjacent segments is not clear. OBJECTIVE:To observe the effect on adjacent segments of osteoporosis patients after pedicle screw fixation augmented with bone cement in early and medium-term fol ow-up period. METHODS:We reviewed the medical information of 87 patients suffering from lumbar disease accompanied with osteoporosis who underwent operation of pedicle screw fixation and posterior lumbar spinal decompression, and the patients were divided into three groups:conventional pedicle screw group, conventional pedicle screw+bone cement group, novel perfusional pedicle screw+bone cement group. The samples were fol owed-up for 6-18 months, averaged 9 months. The Oswestry disability index, intervertebral distance of the upper adjacent segments, deformation index of the upper adjacent vertebral body, concave angle of the fixed lumbar vertebrae superior end-plate and the upper adjacent vertebral body inferior end-plate, and Cobb angle were measured before operation, at 3 days postoperation and during final fol ow-up. RESULTS AND CONCLUSION:The Oswestry disability index of the final fol ow-up in the three groups were decreased when compared with that before operation (P0.05). This showed that in posterior spinal fixation operation, there was no significant difference in the early and medium-term subjective effect between addition of bone cement or not and different adding ways, and addition of bone cement or not and different adding ways could remarkably improve the life quality of the patients. The change of Cobb angle of fixed lumbar vertebrae between the final fol ow-up and 3 days after operation in conventional pedicle screw+bone cement group and novel perfusional pedicle screw+bone cement group was both less than that in the

  18. Simulation of the mechanical behavior of a HIP implant. Implant fixed to bone by cementation under arbitrary load

    Energy Technology Data Exchange (ETDEWEB)

    Oldani, C R [Materials Department - FCEFyN - Universidad Nacional de Cordoba, Av.Velez Sarsfield 1611 (5016) Cordoba (Argentina); Dominguez, A A [INTI Cordoba, Av. Velez Sarsfield 1561 (5016) Cordoba (Argentina)

    2007-11-15

    In a previous work a finite elements model was constructed to simulate a fatigue assay according to the norm IRAM 9422-3. Three materials were studied, two of them are the most used in this type of implant (Stainless steel 3161 and alloy T16A14V) and the third was a new developed titanium alloy (Ti35Nb7Zr5Ta). Static loads were applied to the model according to the highest requirements of the norm and the stress - strain distribution were determined. In this study a simplified analysis of the material's fatigue was done according to the previous work. The best behavior of the titanium alloys vs. the stainless steel was evident. With the objective of studying the behavior of both: the implant and the femur bone, new finite elements models were realized, in which the presence of the bone was considered. Inside the bone, the femoral component of the implant was placed in a similar way of a cemented prosthesis in a total hip arthroplasty. The advantage of the titanium implant related to the stainless steel one, was very clear.

  19. Simulation of the mechanical behavior of a HIP implant. Implant fixed to bone by cementation under arbitrary load

    Science.gov (United States)

    Oldani, C. R.; Dominguez, A. A.

    2007-11-01

    In a previous work a finite elements model was constructed to simulate a fatigue assay according to the norm IRAM 9422-3. Three materials were studied, two of them are the most used in this type of implant (Stainless steel 3161 and alloy T16A14V) and the third was a new developed titanium alloy (Ti35Nb7Zr5Ta). Static loads were applied to the model according to the highest requirements of the norm and the stress - strain distribution were determined. In this study a simplified analysis of the material's fatigue was done according to the previous work. The best behavior of the titanium alloys vs. the stainless steel was evident. With the objective of studying the behavior of both: the implant and the femur bone, new finite elements models were realized, in which the presence of the bone was considered. Inside the bone, the femoral component of the implant was placed in a similar way of a cemented prosthesis in a total hip arthroplasty. The advantage of the titanium implant related to the stainless steel one, was very clear.

  20. Antibiotic-loaded acrylic bone cements: An in vitro study on the release mechanism and its efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Miola, Marta, E-mail: marta.miola@polito.it [Applied Science and Technology Department, Politecnico di Torino (Italy); Bistolfi, Alessandro [Department of Orthopaedics, Traumatology and HM, University of Turin (Italy); AO CTO, M Adelaide Hospital, Turin (Italy); Valsania, Maria Carmen; Bianco, Carlotta [Department of Orthopaedics, Traumatology and HM, University of Turin (Italy); Fucale, Giacomo [Chemical, Clinical and Microbiological Analyses Dept., CTO, Turin (Italy); Verné, Enrica [Applied Science and Technology Department, Politecnico di Torino (Italy)

    2013-07-01

    An in vitro study was carried out in order to investigate the antibiotic release mechanism and the antibacterial properties of commercially (Palacos® R + G and Palacos® LV + G) and manually (Palacos® R + GM and Palacos® LV + GM) blended gentamicin-loaded bone cements. Samples were characterized by means of scanning electron microscopy (SEM) and compression strength was evaluated. The antibiotic release was investigated by dipping sample in simulated body fluid (SBF) and periodically analyzing the solution by means of high pressure liquid chromatography (HPLC). Different antibacterial tests were performed to investigate the possible influence of blending technique on antibacterial properties. Only some differences were observed between gentamicin manually added and commercial ones, in the release curves, while the antibacterial effect and the mechanical properties seem to not feel the blending technique. Highlights: • The efficacy of commercially and manually mixed antibiotic-loaded cements is studied. • Exhaustive mechanical, drug release and antibacterial studies are carried out. • The blending technique does not affect the antibacterial and mechanical properties. • The blending process influences only the release curve, not the released drug amount.

  1. Antibiotic-loaded acrylic bone cements: An in vitro study on the release mechanism and its efficacy

    International Nuclear Information System (INIS)

    An in vitro study was carried out in order to investigate the antibiotic release mechanism and the antibacterial properties of commercially (Palacos® R + G and Palacos® LV + G) and manually (Palacos® R + GM and Palacos® LV + GM) blended gentamicin-loaded bone cements. Samples were characterized by means of scanning electron microscopy (SEM) and compression strength was evaluated. The antibiotic release was investigated by dipping sample in simulated body fluid (SBF) and periodically analyzing the solution by means of high pressure liquid chromatography (HPLC). Different antibacterial tests were performed to investigate the possible influence of blending technique on antibacterial properties. Only some differences were observed between gentamicin manually added and commercial ones, in the release curves, while the antibacterial effect and the mechanical properties seem to not feel the blending technique. Highlights: • The efficacy of commercially and manually mixed antibiotic-loaded cements is studied. • Exhaustive mechanical, drug release and antibacterial studies are carried out. • The blending technique does not affect the antibacterial and mechanical properties. • The blending process influences only the release curve, not the released drug amount

  2. A Novel Injectable Magnesium/Calcium Sulfate Hemihydrate Composite Cement for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Shanchuan Zhang

    2015-01-01

    Full Text Available Objective. A novel injectable magnesium/calcium sulfate hemihydrate (Mg/CSH composite with improved properties was reported here. Methods. Composition, setting time, injectability, compressive strength, and bioactivity in simulated body fluid (SBF of the Mg/CSH composite were evaluated. Furthermore, the cellular responses of canine bone marrow stromal cells (cBMSCs and bone formation capacity after the implantation of Mg/CSH in tibia defects of canine were investigated. Results. Mg/CSH possessed a prolonged setting time and markedly improved injectability and mechanical property p<0.05. Mg/CSH samples showed better degradability than CSH in SBF after 21 days of soaking p<0.05. Moreover, the degrees of cell attachment, proliferation, and capability of osteogenic differentiation on the Mg/CSH specimens were higher than those on CSH, without significant cytotoxicity and with the increased proliferation index, ALP activity, and expression levels of integrin β1 and Coll I in cBMSCs p<0.05. Mg/CSH enhanced the efficiency of new bone formation at the tibia defect area, including the significantly elevated bone mineral density, bone area fraction, and Coll I expression level p<0.05. Conclusions. The results implied that this new injectable bone scaffold exhibited promising prospects for bone repair and had a great potential in bone tissue engineering.

  3. 骨水泥加固椎弓根螺钉的生物力学特性%Biomechanical properties of bone cement injectable canulated pedicle screw

    Institute of Scientific and Technical Information of China (English)

    隆海滨; 孙桂森; 王卫国

    2015-01-01

    BACKGROUND:Bony and structural feature often cause pulout strength decrease of pedicle screw, which induces loosening and pulout, and finaly results in fixation failure. Thus, it is very important to elevate the stability of pedicle screw. OBJECTIVE:To detect the biomechanical stability of bone cement injectable canulated pedicle screw, and to provide reference for bone cement dosage. METHODS: We selected T11-L4 samples of seven fresh adult corpses, containing 40 vertebral bodies. They were randomly divided into bone cement injectable canulated pedicle screw group and DTPSTM pedicle screw group (n=20). After screw implantation, 1, 2, 3 and 5 mL bone cement was injected. The diffuse distribution of bone cement was observed by imaging. The maximum axial pulout strength was measured. RESULTS AND CONCLUSION:When the dose of bone cement was 1-3 mL, the average maximum axial pulout strength was significantly greater in the bone cement injectable canulated pedicle screw group than in the DTPSTM pedicle screw group (P 0.05). The regression equation was Y=25.269X+133.681 (R2=0.837) in the bone cement injectable canulated pedicle screw, and Y=32.039X+99.251 (R2=0.936) in the DTPSTM pedicle screw group. When the dosage of bone cement was 1-5 mL, the maximum axial pulout strength was highly positively correlated with bone cement dosage (|R| > 0.8). These results suggested that bone cement augmentation pedicle screw could apparently elevate the stability of the screw. The maximum axial pulout strength of the pedicle screw was positively correlated with bone cement dosage. After reaching the satisfactory fixation effects, the bone cement injectable canulated pedicle screw can reduce bone cement dosage, diminish the risk of bone cement leakage, and have more advantages than DTPSTM pedicle screw.%背景:由于骨质原因及结构特点导致椎弓根螺钉经常出现把持力下降,从而发生松动、拔出,导致内固定失败,因此提高椎弓根螺钉的稳定

  4. Bone healing response to an injectable calcium phosphate cement with enhanced radiopacity.

    Science.gov (United States)

    Acarturk, Oguz; Lehmicke, Michael; Aberman, Harold; Toms, Derek; Hollinger, Jeffrey O; Fulmer, Mark

    2008-07-01

    The aim of this study was to determine the impact of barium sulfate on remodeling and regeneration in standard tibial defects in rabbits treated with the Norian skeletal repair system (SRS). Two formulations of SRS (with and without barium sulfate) were injected into the medullary canal of the tibia of New Zealand white rabbits. Animals were sacrificed at 6 weeks, 6 months, 1 year, and 2 years. Over the 2-year duration of the study, standard SRS and SRS with barium sulfate appeared to be biocompatible and osteoconductive with no evidence of either inflammation or fibrous tissue around the implant materials or at the bone-material interfaces. This outcome underscores the osteophilic property of the SRS. A difference we observed between the standard SRS and the SRS with barium sulfate was the appearance of acellular material contiguous to the SRS with barium sulfate. Energy dispersive X-ray spectroscopy (EDX) analysis was conducted and confirmed that the acellular material was barium sulfate. Pathological examination of additional tissues including regional lymph nodes revealed neither dissemination of calcium phosphate nor barium sulfate. We concluded that the residual barium sulfate detected by EDX was localized to the intramedullary canal of the tibia. PMID:18098201

  5. Efficiency modeling of solidification/stabilization of multi-metal contaminated industrial soil using cement and additives

    International Nuclear Information System (INIS)

    Highlights: → We assess the feasibility of using soil S/S for industrial land reclamation. → Retarders, accelerators, plasticizers were used in S/S cementitious formulation. → We proposed novel S/S efficiency model for multi-metal contaminated soils. - Abstract: In a laboratory study, formulations of 15% (w/w) of ordinary Portland cement (OPC), calcium aluminate cement (CAC) and pozzolanic cement (PC) and additives: plasticizers cementol delta ekstra (PCDE) and cementol antikorodin (PCA), polypropylene fibers (PPF), polyoxyethylene-sorbitan monooleate (Tween 80) and aqueous acrylic polymer dispersion (Akrimal) were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with up to 157, 32,175, 44,074, 7614, 253 and 7085 mg kg-1 of Cd, Pb, Zn, Cu, Ni and As, respectively. Soils formed solid monoliths with all cementitious formulations tested, with a maximum mechanical strength of 12 N mm-2 achieved after S/S with CAC + PCA. To assess the S/S efficiency of the used formulations for multi-element contaminated soils, we propose an empirical model in which data on equilibrium leaching of toxic elements into deionized water and TCLP (toxicity characteristic leaching procedure) solution and the mass transfer of elements from soil monoliths were weighed against the relative potential hazard of the particular toxic element. Based on the model calculation, the most efficient S/S formulation was CAC + Akrimal, which reduced soil leachability of Cd, Pb, Zn, Cu, Ni and As into deionized water below the limit of quantification and into TCLP solution by up to 55, 185, 8750, 214, 4.7 and 1.2-times, respectively; and the mass transfer of elements from soil monoliths by up to 740, 746, 104,000, 4.7, 343 and 181-times, respectively.

  6. Efficiency modeling of solidification/stabilization of multi-metal contaminated industrial soil using cement and additives

    Energy Technology Data Exchange (ETDEWEB)

    Voglar, Grega E. [RDA - Regional Development Agency Celje, Kidriceva ulica 25, 3000 Celje (Slovenia); Lestan, Domen, E-mail: domen.lestan@bf.uni-lj.si [Agronomy Department, Centre for Soil and Environmental Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana (Slovenia)

    2011-08-30

    Highlights: {yields} We assess the feasibility of using soil S/S for industrial land reclamation. {yields} Retarders, accelerators, plasticizers were used in S/S cementitious formulation. {yields} We proposed novel S/S efficiency model for multi-metal contaminated soils. - Abstract: In a laboratory study, formulations of 15% (w/w) of ordinary Portland cement (OPC), calcium aluminate cement (CAC) and pozzolanic cement (PC) and additives: plasticizers cementol delta ekstra (PCDE) and cementol antikorodin (PCA), polypropylene fibers (PPF), polyoxyethylene-sorbitan monooleate (Tween 80) and aqueous acrylic polymer dispersion (Akrimal) were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with up to 157, 32,175, 44,074, 7614, 253 and 7085 mg kg{sup -1} of Cd, Pb, Zn, Cu, Ni and As, respectively. Soils formed solid monoliths with all cementitious formulations tested, with a maximum mechanical strength of 12 N mm{sup -2} achieved after S/S with CAC + PCA. To assess the S/S efficiency of the used formulations for multi-element contaminated soils, we propose an empirical model in which data on equilibrium leaching of toxic elements into deionized water and TCLP (toxicity characteristic leaching procedure) solution and the mass transfer of elements from soil monoliths were weighed against the relative potential hazard of the particular toxic element. Based on the model calculation, the most efficient S/S formulation was CAC + Akrimal, which reduced soil leachability of Cd, Pb, Zn, Cu, Ni and As into deionized water below the limit of quantification and into TCLP solution by up to 55, 185, 8750, 214, 4.7 and 1.2-times, respectively; and the mass transfer of elements from soil monoliths by up to 740, 746, 104,000, 4.7, 343 and 181-times, respectively.

  7. Surgical treatment of the osteoporotic spine with bone cement-injectable cannulated pedicle screw fixation: technical description and preliminary application in 43 patients

    Directory of Open Access Journals (Sweden)

    Fei Dai

    2015-02-01

    Full Text Available OBJECTIVES: To describe a new approach for the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws. METHODS: Between June 2010 and February 2013, 43 patients with degenerative spinal disease and osteoporosis (T-score <-2.5 underwent lumbar fusion using cement-injectable cannulated pedicle screws. Clinical outcomes were evaluated using a Visual Analog Scale and the Oswestry Disability Index. Patients were given radiographic follow-up examinations after 3, 6, and 12 months and once per year thereafter. RESULTS: All patients were followed for a mean of 15.7±5.6 months (range, 6 to 35 months. The Visual Analog Scale and Oswestry Disability Index scores showed a significant reduction in back pain (p = 0.018 and an improvement in lower extremity function (p = 0.025 in patients who underwent lumbar fusion using the novel screw. Intraoperative cement leakage occurred in four patients, but no neurological complications were observed. Radiological observation indicated no loosening or pulling out of the novel screw, and bone fusion was excellent. CONCLUSIONS: The described polymethylmethacrylate augmentation technique using bone cement-injectable cannulated pedicle screws can reduce pain and improve spinal dysfunction in osteoporotic patients undergoing osteoporotic spine surgery.

  8. Effect of addition of nano-hydroxyapatite on physico-chemical and antibiofilm properties of calcium silicate cements

    Science.gov (United States)

    GUERREIRO-TANOMARU, Juliane Maria; VÁZQUEZ-GARCÍA, Fernando Antonio; BOSSO-MARTELO, Roberta; BERNARDI, Maria Inês Basso; FARIA, Gisele; TANOMARU, Mario

    2016-01-01

    ABSTRACT Objective Mineral Trioxide Aggregate (MTA) is a calcium silicate cement composed of Portland cement (PC) and bismuth oxide. Hydroxyapatite has been incorporated to enhance mechanical and biological properties of dental materials. This study evaluated physicochemical and mechanical properties and antibiofilm activity of MTA and PC associated with zirconium oxide (ZrO2) and hydroxyapatite nanoparticles (HAn). Material and Methods White MTA (Angelus, Brazil); PC (70%)+ZrO2 (30%); PC (60%)+ZrO2 (30%)+HAn (10%); PC (50%)+ZrO2 (30%)+HAn (20%) were evaluated. The pH was assessed by a digital pH-meter and solubility by mass loss. Setting time was evaluated by using Gilmore needles. Compressive strength was analyzed by mechanical test. Samples were radiographed alongside an aluminum step wedge to evaluate radiopacity. For the antibiofilm evaluation, materials were placed in direct contact with E. faecalis biofilm induced on dentine blocks. The number of colony-forming units (CFU mL-1) in the remaining biolfilm was evaluated. The results were submitted to ANOVA and the Tukey test, with 5% significance. Results There was no difference in pH levels of PC+ZrO2, PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p>0.05) and these cements presented higher pH levels than MTA (p<0.05). The highest solubility was observed in PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p<0.05). MTA had the shortest initial setting time (p<0.05). All the materials showed radiopacity higher than 3 mmAl. PC+ZrO2 and MTA had the highest compressive strength (p<0.05). Materials did not completely neutralize the bacterial biofilm, but the association with HAn provided greater bacterial reduction than MTA and PC+ZrO2 (p<0.05) after the post-manipulation period of 2 days. Conclusions The addition of HAn to PC associated with ZrO2 harmed the compressive strength and solubility. On the other hand, HAn did not change the pH and the initial setting time, but improved the radiopacity (HAn 10%), the final setting time

  9. Estudio experimental de la osteosustitución con biomateriales cerámicos formulados como cementos óseos Experimental study of the bone substitution with ceramic biomaterials formulated as bone cements

    Directory of Open Access Journals (Sweden)

    E S Sanzana

    2007-01-01

    Full Text Available Los biomateriales cerámicos presentan interesantes propiedades biológicas, por lo que pueden ser utilizados en la sustitución ósea. En este estudio fueron comparados dos cementos óseos de fosfato de calcio con el autoinjerto óseo esponjoso. Se realizó un defecto cavitario de 6 mm en la metáfisis femoral distal derecha de 36 conejos machos Oryctolagus cuniculi. Los animales fueron divididos en 3 grupos de 12 conejos, que recibieron como implantes cemento de fosfato a tricálcico (TPC, cemento de fosfato monocálcico (MPC y autoinjerto óseo (CON. Los estudios radiológico e histológico han mostrado una correcta sustitución de ambos biomateriales por hueso neoformado. El estudio histomorfométrico ha revelado que la neoformación ósea obtenida con los 2 cementos, tanto a las 4 como las 12 semanas, es equivalente a la generada por el injerto óseo. No se han encontrado diferencias significativas en la reabsorción de los materiales. Finalmente, este trabajo ha concluido que los cementos óseos de fosfato de calcio son materiales osteoconductivos, osteotransductivos y biocompatibles que se comportan como sustitutivos óseos.Ceramic biomaterials have interesting biological properties that can be used in bone substitution. In this study two calcium phosphate bone cements were compared to cancellous bone autograft. A bone cavitary defect of 6 mm in diameter was carried out in the right distal femoral methaphyses of 36 male rabbits Oryctolagus cuniculi. The animals were divided into 3 groups of 12 rabbits receiving a tricalcium phosphate cement (TPC, monocalcium phosphate cement (MPC and autologous bone (CON as implants. The radiological and histological studies showed a correct substitution of both biomaterials with new bone. The histomorphometric study revealed that the bone neoformation obtained with the two cements at 4 and 12 weeks is equivalent to the bone generated by the bone graft. There were no significant differences in the

  10. A correlative imaging based methodology for accurate quantitative assessment of bone formation in additive manufactured implants.

    Science.gov (United States)

    Geng, Hua; Todd, Naomi M; Devlin-Mullin, Aine; Poologasundarampillai, Gowsihan; Kim, Taek Bo; Madi, Kamel; Cartmell, Sarah; Mitchell, Christopher A; Jones, Julian R; Lee, Peter D

    2016-06-01

    A correlative imaging methodology was developed to accurately quantify bone formation in the complex lattice structure of additive manufactured implants. Micro computed tomography (μCT) and histomorphometry were combined, integrating the best features from both, while demonstrating the limitations of each imaging modality. This semi-automatic methodology registered each modality using a coarse graining technique to speed the registration of 2D histology sections to high resolution 3D μCT datasets. Once registered, histomorphometric qualitative and quantitative bone descriptors were directly correlated to 3D quantitative bone descriptors, such as bone ingrowth and bone contact. The correlative imaging allowed the significant volumetric shrinkage of histology sections to be quantified for the first time (~15 %). This technique demonstrated the importance of location of the histological section, demonstrating that up to a 30 % offset can be introduced. The results were used to quantitatively demonstrate the effectiveness of 3D printed titanium lattice implants. PMID:27153828

  11. A laboratory investigation to assess the influence of cement augmentation of screw and plate fixation in a simulation of distal femoral fracture of osteoporotic and non-osteoporotic bone.

    Science.gov (United States)

    Wähnert, D; Lange, J H; Schulze, M; Gehweiler, D; Kösters, C; Raschke, M J

    2013-10-01

    The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017). PMID:24078541

  12. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  13. THE INFLUENCE OF CaO AND P2O5 OF BONE ASH UPON THE REACTIVITY AND THE BURNABILITY OF CEMENT RAW MIXTURES

    Directory of Open Access Journals (Sweden)

    TOMÁŠ IFKA

    2012-03-01

    Full Text Available The influence of CaO and P2O5 upon the reactivity of cement raw meal was investigated in this paper. Ash of bone meal containing Ca3(PO42 - 3CaO·P2O5 was used as the source of P2O5. Two series of samples with different content of the ash of bone meal were prepared. In the first series, the ash of bone was added into cement raw meal. The second series of samples were prepared by considering ash as one of CaO sources. Therefore, the total content of CaO in cement raw meal was kept constant, while the amount of P2O5 increased. These different series of samples were investigated by analyzing free lime content in the clinkers. The XRD analysis and Electron Micro Probe Analyzer analysis of the clinkers were also carried out. Two parameters were used to characterize the reactivity of cement raw meal: content of free lime and Burnability Index (BI calculated from free lime content in both series of samples burnt at 1350 ºC, 1400 ºC, 1450 ºC and 1500 ºC. According to the first parameter, P2O5 content that drastically makes worse the reactivity of cement raw meal was found at 1.11 wt.% in the first series, while this limit has reached 1.52 wt.% in the second one. According to the BI, the limit of P2O5 was found at 1.42 wt. % in the first series and 1, 61 wt.% in the second one. Furthermore, EPMA has demonstrated the presence of P2O5 in both calcium silicate phases forming thus solid solutions.

  14. Effect of Water Addition on Rheological Behaviour of Bauxite Based Low-cement Castables

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xianxin; Michel RIGANU; ZHOU Ningsheng

    2004-01-01

    Water addition has direct impact on castables and needs to be under control placement and properties, In this work, two rheological properties, flow resistance and torque viscosity, have been measured against time, with different water addition in the same bauxile-based LC Castable mix. The flow resistance indicates the mobility,whereas the torque viscosity dictates the stability of a castable during installation. It has been observed that with 6.0 wt % water addition, such a mix possesses good vibration castable characteristics; with 6.5 wt% , it shows good self-flow castable characteristics; and with 7. 0wt %, it can be a good pumpable castable, in every case with comparable mechanical properties. While with 7.5wt % water addition, the properties of such castable aredefinitively impaired.

  15. Influence of Environmentally Friendly and High-Efficiency Composite Additives on Pulverized Coal Combustion in Cement Industry

    Directory of Open Access Journals (Sweden)

    Zhiyong Wang

    2016-01-01

    Full Text Available 4 kinds of chemical reagents and 3 kinds of industrial wastes were selected as burning additives for 2 kinds of coals in cement industry. The work focused on the replacement of partial chemical reagents by industrial wastes, which not only reduced the cost and took full advantage of industrial wastes, but also guaranteed the high combustion efficiency and removed the NOX and SO2 simultaneously. The experiments were carried out in DTF. The combustion residues were analyzed by SEM and XRD. The results showed that the burnout rate was increased after adding the additives; meanwhile, the NOX and SO2 release concentration were reduced, but the degree of action varied for different additives and coals. The substitute of chemical reagents by industrial wastes was very effective; overall, the cold-rolled iron oxide worked better than others; the particles surface was tougher and the peaks of crystalline phase were lower than raw coal, which indicated that the additives played good roles in combustion process.

  16. Effect of mineral additives (natural pozzolana and sand of dunes) by substitution of cement on the performance and durability of mortars

    Science.gov (United States)

    Saidi, M.; Safi, B.

    2016-04-01

    The objective of our work consists of the study of the substitution effects of clinker by mineral additions such as: natural pozzolana (PZ) and the sand of dunes (SD) finely crushed on the mechanical properties and the durability of the mortars worked out according to various combinations containing these additions. The results from this research confirm that the substitution of 20% to 30% of cement APC (Artificial Portland Cement) by additions in binary cement (APC + PZ) or ternary (APC + PZ + SD) contributes positively to the mechanical strength of mortars and resistance to the chemical attacks in various corrosive conditions such as: hydrochloric acid, sulfuric acid and nitric acid. The mechanical strength of the different variants is comparable to those of the APC. The test results of the weight loss and phenolphthalein shows that the chemical resistance of variants (PZ20) and (PZ20 with SD5) are larger compared to the reference mortar APC and other variants. This study shows that adding value by substituting a part of clinker. This substitution can save 20% to 30% of clinker used for the manufacture of cement; this will have a beneficial effect for cement and economically (less energy spent for the clinker burning). This study contributes to the protection of the environment as to produce one ton of clinker generates about one ton of CO2 is harmful to the atmosphere. Based on our results we will reduce from 20% to 30% CO2 gas responsible for the greenhouse effect.

  17. Injectable citrate-modified Portland cement for use in vertebroplasty.

    Science.gov (United States)

    Wynn-Jones, Gareth; Shelton, Richard M; Hofmann, Michael P

    2014-11-01

    The injectability of Portland cement (PC) with several citrate additives was investigated for use in clinical applications such as vertebroplasty (stabilization of a fractured vertebra with bone cement) using a syringe. A 2-wt % addition of sodium or potassium citrate with PC significantly improved cement injectability, decreased cement setting times from over 2 h to below 25 min, while increasing the compressive strength to a maximum of 125 MPa. Zeta-potential measurements indicated that the citrate anion was binding to one or more of the positively charged species causing charged repulsion between cement particles which dispersed aggregates and caused the liquefying effect of the anion. Analysis of the hydrating phases of PC indicated that the early strength producing PC phase (ettringite) developed within the first 2 h of setting following addition of the citrate anion, while this did not occur in the control cement (PC only). Within 24 h ettringite developed in PC as well as calcium-silicate-hydrate (C-S-H), the major setting phase of PC, whereas cements containing citrate did not develop this phase. The evidence suggested that in the presence of citrate the cements limited water supply appeared to be utilized for ettringite formation, producing the early strength of the citrate cements. The present study has demonstrated that it is possible to modify PC with citrate to both improve the injectability and crucially reduce the setting times of PC while improving the strength of the cement. PMID:24711245

  18. Osseointegration of titanium implants by addition of recombinant bone morphogenetic protein 2 (rhBMP-2)

    Energy Technology Data Exchange (ETDEWEB)

    Lichtinger, T.K.; Mueller, R.T.; Schuermann, N.; Oldenburg, M. [Essen Univ. (Germany). Dept. of Orthopaedic Surgery; Wiemann, M. [Inst. of Physiology, Univ. of Essen (Germany); Chatzinikolaidou, M.; Jennissen, H.P. [Inst. of Physiological Chemistry, Univ. of Essen (Germany); Rumpf, H.M.

    2001-12-01

    The osseointegration of long-term implants is often incomplete such that gaps remain between the implant surface and the surrounding hard tissue. This study examines the effect of soluble recombinant human bone morphogenic protein 2 (rhBMP-2) on gap healing and osseous integration. The effect of a single, intraoperative application of soluble rhBMP-2 on the formation of new bone around titanium implants was studied. A total of 8 titanium-alloy cylinders (Ti-6Al-4V) with a plasma spray coating (TPS; 400 {mu}m thickness) were implanted into femoral condyles of mature sheep: rhBMP-2 solution (1 {mu}g) was pipetted into the 1 mm wide cleft around 4 implants; 4 further implants served as rhBMP-2-free controls. Two of these controls exhibited an additional calciumphosphate-coating. The cleft around the implants served as testing zone to study the formation of new bone by microradiographical and histological analyses. The follow-up periods were 4 and 9 weeks, respectively. A significant amount of new bone contacting the implants' surface was detected where rhBMP-2-solution had been used: In 50% a circumferential osseoinduction occurred within 4 weeks and a nearly complete osseointegration was observed after 9 weeks. In all cases bone formation was exaggerated and filled the spongiosa with compact bone. Time matched TPS-controls and controls with calciumphosphate coating showed no notable formation of new bone. The results suggest that a single administration of soluble rhBMP-2 into a bone cavity can augment bone formation and also osseointegration of titanium implants. Further investigations based on these findings are necessary to develop long-term implants (e.g. joint replacements) with rhBMP-2-biocoating for humans. (orig.)

  19. Revision stapes surgery for lysis of the long process of the incus: comparing hydroxyapatite bone cement versus malleovestibulopexy and total ossicular replacement prosthesis.

    Science.gov (United States)

    Pitiot, Vincent; Hermann, Ruben; Tringali, Stéphane; Dubreuil, Christian; Truy, Eric

    2016-09-01

    The objective of the study was to report audiological results in revision stapes surgery, comparing hydroxyapatite (HAP) bone cement, malleovestibular (MV) prosthesis, and total ossicular replacement prosthesis (TORP). The study is a retrospective case review conducted in a tertiary referral center. Patients treated for revision stapes surgery from 2010 to 2014, where a lysis of the long process of the incus (LPI) was observed with the use of HAP bone cement, MV prosthesis, or a TORP were included in the study. The main outcomes measured were pre- and postoperative bone conduction (BC) and air conduction (AC) pure-tone averages (PTA) (0.5, 1, 2, 3 kHz), including high frequencies BC (HFBC) (1, 2, 3, 4 kHz) and air-bone gap (ABG). 107 revision stapes surgery were performed in 96 ears. Main cause of failure was LPI lysis in 38 cases (39.6 %). 31 patients were analyzed: HAP bone cement was used in 11 patients (Group I), MV prosthesis in ten patients (Group II), and TORP in ten patients (Group III). The mean post-operative ABG was 10.7 dB (±7.4) (p = 0.003), 10.7 dB (±8.8) (p = 0.001), and 16.9 dB (±9.8) (p = 0.001), respectively. There were no significant differences between groups. In Group I, the mean change in HFBC revealed an improvement of 5.6 dB (±7.9) (p = 0.03), while in Group III there was a significant deterioration of the thresholds of 5.8 dB (±7.6) (p = 0.04). There were no cases of post-operative anacusis. In revision stapes surgery when LPI is eroded, we recommend to perform a cement ossiculoplasty for stabilizing a standard Teflon piston when LPI is still usable, the LPI lengthening with cement being not recommended. When LPI is too eroded, we prefer performing a malleovestibulopexy, and reserve TORP for cases with a bad anatomical presentation. PMID:26690574

  20. Estimation of the resident's additional dose in bone-coal mining areas of the five provinces

    Institute of Scientific and Technical Information of China (English)

    JIANG Shan; ZHANG Liang; YE Ji-Da; KONG Ling-Li; LI Ying; SHI Jin-Hua; WU Zong-Mei

    2005-01-01

    This paper introduces the resident's additional dose in bone-coal mining areas. The increase of the annual additional effective doses accepted by the residents living in the carbide-brick houses, the staffs working in the carbide-brick houses and the miners working in the bone-coal mining areas of Hubei, Hunan, Jiangxi, Zhejiang and Anhui Provinces is caused by the rising of environmental radioactive level. The investigation of natural background radiation in the bone-coal mining areas indicated that both mining and utilizing bone-coal cause the rise of environmental radioactive level. The ranges of the annual additional effective dose accepted by the residents, staffs and miners is 1.9-6.8 mSv, 0.5-2.0 mSv and 8.2-71 mSv, and with an average of 3.8 mSv, 1 mSv and 40 mSv, respectively. The annual additional effective doses accepted by part residents and staffs exceed the dose limit of 1 mSv for public exposure, and part miners exceed the dose limit of 20 mSv for occupational exposure. And the contribution of dose caused by inhaled radon to the total additional effective dose is over 76%.

  1. Estimation of the resident's additional dose in bone-coal mining areas of the five provinces

    International Nuclear Information System (INIS)

    This paper introduces the resident's additional dose in bone-coal mining areas. The increase of the annual additional effective doses accepted by the residents living in the carbide-brick houses, the staffs working in the carbide-brick houses and the miners working in the bone-coal mining areas of Hubei, Hunan, Jiangxi, Zhejiang and Anhui Provinces is caused by the rising of environmental radioactive level. The investigation of natural background radiation in the bone-coal mining areas indicated that both mining and utilizing bone-coal cause the rise of environ- mental radioactive level. The ranges of the annual additional effective dose accepted by the residents, staffs and miners is 1.9-6.8 mSv, 0.5-2.0 mSv and 8.2-71 mSv, and with an average of 3.8 mSv, 1 mSv and 40 mSv, respectively. The annual additional effective doses accepted by part residents and staffs exceed the dose limit of 1 mSv for public exposure, and part miners exceed the dose limit of 20 mSv for occupational exposure. And the contribution of dose caused by inhaled radon to the total additional effective dose is over 76%. (authors)

  2. Evaluation of the chemical modifications in petroleum asphalt cement with the addition of polypropylene

    International Nuclear Information System (INIS)

    Studies show that the common distress mode in the Brazilian highway network are fatigue cracks and plastic deformation, which are associated with the type of material used in the pavement layers, structural project, excessive traffic load and weathering. To minimize these defects, research on modifiers such as polymers, added to asphalt binders have been developed to provide physical, chemical and rheological improvement. This paper investigates chemical modifications of the binders with the addition of PP by FTIR, NMR and DSC. FTIR spectra of pure and modified binder showed no differences in absorption. NMR analysis showed no strong chemical bonds between the binder and PP. DSC curve of PP showed a melting temperature of 160 deg C (ΔH = 94J/g) and the pure binder presented an endothermic transition between 20 and 40 deg C (ΔH = 2J/g). In the DSC curves of mixtures, these transitions are not significant, indicating possible interactions between asphalt binder and PP. (author)

  3. 水泥与混凝土外加剂适应性地解决%Adaptability solution of cement and concrete additive

    Institute of Scientific and Technical Information of China (English)

    封培然

    2014-01-01

    结合XM水泥厂具体情况,在对影响其水泥与混凝土外加剂适应性因素进行分析,提出改善熟料冷却速度,降低出厂水泥中温度,更换原燃材料,使用助磨剂等建议与措施。在实施部分措施后,XM水泥与外加剂的适应性差的问题得到较好解决。%The factors of compatibility between cement and concrete additive were analysed, combined with particular case of XM ce-ment plant, a series of measures were put forward including clinker cooling speed improvement, reducing finished cement temperature, changing raw material and fuel and using grinding agent, etc. By some measures, the adaptability problems between cement and concret dditive of XM cement plant were solved sucessfully.

  4. EFFECT OF QUARTZ/MULLITE BLEND CERAMIC ADDITIVE ON IMPROVING RESISTANCE TO ACID OF SODIUM SILICATE-ACTIVATED SLAG CEMENT. CELCIUS BRINE.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA, T.; BROTHERS, L.E.; VAN DE PUTTE, T.R.

    2006-06-01

    We evaluated the usefulness of manufactured quartz/mullite blend (MQMB) ceramic powder in increasing the resistance to acid of sodium silicate-activated slag (SSAS) cementitious material for geothermal wells. A 15-day exposure to 90{sup o} CO{sub 2}-laden H{sub 2}SO{sub 4} revealed that the MQMB had high potential as an acid-resistant additive for SSAS cement. Two factors, the appropriate ratio of slag/MQMB and the autoclave temperature, contributed to better performance of MQMB-modified SSAS cement in abating its acid erosion. The most effective slag/MQMB ratio in minimizing the loss in weight by acid erosion was 70/30 by weight. For autoclave temperature, the loss in weight of 100 C autoclaved cement was a less than 2%, but at 300 C it was even lower. Before exposure to acid, the cement autoclaved at 100 C was essentially amorphous; increasing the temperature to 200 C led to the formation of crystalline analcime in the zeolitic mineral family during reactions between the mullite in MQMB and the Na from sodium silicate. In addition, at 300 C, crystal of calcium silicate hydrate (1) (CSH) was generated in reactions between the quartz in MQMB and the activated slag. These two crystalline phases (CSH and analcime) were responsible for densifying the autoclaved cement, conveying improved compressive strength and minimizing water permeability. The CSH was susceptible to reactions with H{sub 2}SO{sub 4}, forming two corrosion products, bassanite and ionized monosilicic acid. However, the uptake of ionized monosilicic acid by Mg dissociated from the activated slag resulted in the formation of lizardite as magnesium silicate hydrate. On the other hand, the analcime was barely susceptible to acid if at all. Thus, the excellent acid resistance of MQMB-modified SSAS cement was due to the combined phases of lizardite and analcime.

  5. Outcome of long-axis percutaneous sacroplasty for the treatment of sacral insufficiency fractures with a radiofrequency-induced, high-viscosity bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, Katrin [University of Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); J. W. Goethe University of Frankfurt, Institute for Diagnostic and Interventional Radiology, Frankfurt (Germany); Zangos, Stephan; Vogl, Thomas J. [University of Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Mack, Martin G. [Radiology Munich, Munich (Germany); Marzi, Ingo [University of Frankfurt, Department of Trauma, Hand and Reconstructive Surgery, Frankfurt (Germany)

    2014-04-15

    Our goal was to assess the technical results in patients who underwent long-axis sacroplasty for the treatment of sacral insufficiency fractures (SIF) by radiofrequency-induced high-viscosity bone cement augmentation. Twelve patients with bilateral sacral fractures were treated by augmentation with radiofrequency-activated, high-viscosity polymethylmethacrylate (PMMA) bone cement under local anesthesia. CT-guided sacroplasty was performed by using a long-axis approach through a single entry point. Thirty-six vertebrae were treated in 12 sessions under a combination of CT and fluoroscopic guidance using a bilateral access and a cavity-creating osteotome prior to remote-controlled, hydraulically driven cement injection. The visual analogue scale (VAS) score before sacroplasty and at 1 and 3 months after the treatment was obtained. PMMA leaks were evaluated retrospectively using the post-interventional CT. The mean amount of high-viscosity PMMA injected per patient was 7.8 ml. No major adverse events were observed. In the first 4 days after the procedure, the mean VAS score decreased from 8.1 ± 1.9 to mean 3.1 ± 1.2 and was followed by a gradual but continuous decrease throughout the rest of the follow-up period at 24 weeks (mean 2.2 ± 1.1) and 48 weeks (mean 2.1 ± 1.4). CT fluoroscopy-guided sacral augmentation was safe and effective in all 12 patients with osteoporotic SIF. (orig.)

  6. Development of highly-filled, bioactive acrylic-based composite bone cements for orthopedic and craniofacial surgery: Tuning of material properties after incorporation of calcium phosphate and antimicrobial fillers

    Science.gov (United States)

    Rodriguez, Lucas Carlos

    Bone cements are used in a variety of healthcare specialties ranging from orthopedics to dentistry to craniofacial surgery to spinal disc reconstruction. These materials need characteristics which mimic their surrounding tissues. Currently available materials have struggled to maintain these necessary characteristics. Poly (methyl methacrylate) is a very high strength bio-inert polymer which has been utilized in healthcare since the 1940's. Calcium phosphate cements are well established as being bone mimicking, but cannot sustain the compressive loads in a weight bearing application. This study sought to solve the problem of currently available bone cements by filling calcium phosphates and antimicrobials into an acrylic polymer matrix. The intended outcome was a material capable of retaining high mechanical stability from the acrylic polymer phase, while becoming sufficiently bone mimicking and antimicrobial. This thesis work presented, characterizes the material properties of the developed materials and eventually isolates a material of interest for future studies.

  7. Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review.

    Science.gov (United States)

    Wang, Xiaojian; Xu, Shanqing; Zhou, Shiwei; Xu, Wei; Leary, Martin; Choong, Peter; Qian, M; Brandt, Milan; Xie, Yi Min

    2016-03-01

    One of the critical issues in orthopaedic regenerative medicine is the design of bone scaffolds and implants that replicate the biomechanical properties of the host bones. Porous metals have found themselves to be suitable candidates for repairing or replacing the damaged bones since their stiffness and porosity can be adjusted on demands. Another advantage of porous metals lies in their open space for the in-growth of bone tissue, hence accelerating the osseointegration process. The fabrication of porous metals has been extensively explored over decades, however only limited controls over the internal architecture can be achieved by the conventional processes. Recent advances in additive manufacturing have provided unprecedented opportunities for producing complex structures to meet the increasing demands for implants with customized mechanical performance. At the same time, topology optimization techniques have been developed to enable the internal architecture of porous metals to be designed to achieve specified mechanical properties at will. Thus implants designed via the topology optimization approach and produced by additive manufacturing are of great interest. This paper reviews the state-of-the-art of topological design and manufacturing processes of various types of porous metals, in particular for titanium alloys, biodegradable metals and shape memory alloys. This review also identifies the limitations of current techniques and addresses the directions for future investigations. PMID:26773669

  8. Study on silicate-calcium phosphate composite bone cement modified by sodium carbonate solution%碳酸钠液相改性硅-磷酸钙复合骨水泥研究

    Institute of Scientific and Technical Information of China (English)

    李青林; 杨帮成

    2014-01-01

    以质量分数70%的硅酸三钙(Ca3 SiO5,C3 S)和30%磷酸氢钙(CaHPO4·2H2 O,DCPD)复合得到的 DCP30粉体材料为固相,以不同浓度碳酸钠溶液为液相,得到碳酸钠改性骨水泥材料。使用 X 射线衍射(XRD)、扫描电镜(SEM)、万能材料试验机等手段对不同浓度改性材料进行表征。结果显示:添加碳酸钠液相,骨水泥初、终凝时间分别缩短至16和55 min;调控碳酸钠液相浓度,可以实现短期抗压强度优化;使用碳酸钠后,固化自发生成羟基磷灰石(HA)。浸泡模拟体液(SBF)7天,材料表面覆盖 HA 沉积层,生物活性优越。碳酸钠液相改性硅-磷酸钙复合骨水泥体系的水化性能、短期力学性能以及生物活性均优于Ca3 SiO5水泥和未改性硅-磷酸钙复合骨水泥,是一种良好的生物活性骨修复材料。%Sodium carbonate solution modified bone cement materials have been prepared using sodium carbonate solution with dif-ferent concentration as liquid phase and DCP30 powder material obtained by 70% mass fraction tricalcium silicate (Ca3 SiO5 ,C3 S) and 30% dicalcium phosphate (CaHPO4 ·2H2 O,DCPD)as the solid phase.The materials were characterized by the means of X-ray diffraction (XRD),scanning electron microscope (SEM)and mechanical test.The results show that the initial and final set-ting time of bone cement is reduced to 16 and 55 min by the addition of sodium carbonate solution.The short-term mechanical strength can be optimized by controlling the concentration of sodium carbonate solution.Hydroxyapatite (HA)can spontaneously form after the use of sodium carbonate solution.HA forms on the surface of bone-cement after immersion in SBF for 7 days,indi-cating its good bioactivity.The modified system shows better hydraulic property,bioactivity and mechanical strength than Ca3 SiO5 cement and unmodifiled silicate-calcium phosphate composite bone cement,suggesting the new system is a

  9. EFFECT OF CALCIUM ADDITION ON THE DEFLUORIDATION CAPACITY OF BONE CHAR

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    Dosage of small amounts of calcium chloride to fluoride water prior to contact with bone char which has already been saturated with fluoride is shown to provide an additional fluoride removal capacity. The additionally obtained removal capacity increases with slower filtration velocities and...... capable of reducing the fluoride concentration form 10 to about 0.5 mgF/L. The additionally saturated column is shown to be regenerated by simple adjustment of the pH of the water to 11 and allowing to flow for a few bed volumes. The useful regeneration capacity, where the fluoride concentration is...

  10. 万古霉素骨水泥治疗骨髓炎的临床分析%Vancomycin analysis of bone cement in the treatment of osteomyelitis

    Institute of Scientific and Technical Information of China (English)

    王立强

    2013-01-01

      目的研究万古霉素骨水泥对骨髓炎患者的临床效果。方法将72例骨髓炎患者随机分为两组各36例,对照组采用常规治疗方式,治疗组采用万古霉素骨水泥治疗。结果治疗组患者骨髓炎症状治疗效果明显优于对照组;症状控制时间和住院治疗时间明显短于对照组。结论应用万古霉素骨水泥对骨髓炎实施治疗的临床效果非常明显。%Objective To application of vancomycin bone cement for the treatment of patients with osteomyelitis is carried out to study the clinical effect. Methods 72 cases of patients with osteomyelitis, randomly divided into control group and treatment group, 36 cases in each group on average. The conventional treatment in patients with the control group; Using vancomycin treatment bone cement for the treatment group patients. Results The treatment group patients with meningitis symptoms treatment effect is better than the control group; Symptom control time and hospitalization time significantly shorter than the control group. Conclusion Application of vancomycin bone cement for the treatment of patients with osteomyelitis implementation effect is very obvious.

  11. Bone Marrow Nails Created by Percutaneous Osteoplasty for Long Bone Fracture: Comparisons Among Acrylic Cement Alone, Acrylic-Cement–Filled Bare Metallic Stent, and Acrylic-Cement–Filled Covered Metallic Stent

    International Nuclear Information System (INIS)

    Purpose: This study was designed to compare the strength among bone marrow nails created to treat long bone fractures using interventional procedures. Methods: Twelve resected intact tibiae of healthy swine were used. A circumferential bone fracture was made in nine tibiae and restored with the following created bone marrow nails: acrylic cement alone (ACA) (n = 3), acrylic-cement–filled bare metallic stent (AC-FBMS) (n = 3), and acrylic-cement–filled covered metallic (AC-FCMS) stent (n = 3). The remaining intact tibiae (n = 3) were used as controls. Results: A bone marrow nail was successfully achieved within 30 min in all swine. The maximum injection volume of acrylic cement for creating ACA, AC-FBMS, and AC-FCMS was 1.7 ± 0.3, 3.2 ± 0.4, and 2.9 ± 0.4 mL, respectively. The thickness of bone marrow nail created in the ACA, AC-FBMS, and AC-FCMS groups was 3.6 ± 1.0, 10.3 ± 0.26, and 9.6 ± 0.32 mm, respectively (AC-FBMS group versus AC-FCMS group, p = 0.038), probably because of leakage of acrylic cement surrounding the interstices. The maximum bending power (kilonewton) and bending strength (newton/mm2) in the normal long bone, ACA, AC-FBMS, and AC-FCMS groups were: 1.70 ± 0.25 and 79.2 ± 16.1; 0.21 ± 0.11 and 8.8 ± 2.8; 0.46 ± 0.06 and 18.2 ± 1.6; and 0.18 ± 0.04 and 7.8 ± 2.7, respectively. Conclusions: Although the maximum bending power and bending strength of AC-FBMS were not satisfactory, it was the most robust of the three marrow nails for restoring fractured long bone.

  12. Influencing the corrosion resistance of cemented carbides by addition of Cr2C3, TiC and TaC

    International Nuclear Information System (INIS)

    Corrosion resistance of different cemented carbides has been investigated. As parameters different binder content and refractory metal carbide additions were studied in various media with different pH values. As media 1n sulphuric acid, sodium sulphate and sodium hydroxide solution were used. An increase of pH shifted corrosion potential to more negative values due to lower current densities of cathodic reaction. Additions of refractory metal carbides such as Cr3C2, TiC and TaC increased corrosion resistance. The effect of carbide addition is discussed. (author)

  13. Development of nanosilica bonded monetite cement from egg shells

    International Nuclear Information System (INIS)

    This work represents further effort from our group in developing monetite based calcium phosphate cements (CPC). These cements start with a calcium phosphate powder (MW-CPC) that is manufactured using microwave irradiation. Due to the robustness of the cement production process, we report that the starting materials can be derived from egg shells, a waste product from the poultry industry. The CPC were prepared with MW-CPC and aqueous setting solution. Results showed that the CPC hardened after mixing powdered cement with water for about 12.5 ± 1 min. The compressive strength after 24 h of incubation was approximately 8.45 ± 1.29 MPa. In addition, adding colloidal nanosilica to CPC can accelerate the cement hardening (10 ± 1 min) process by about 2.5 min and improve compressive strength (20.16 ± 4.39 MPa), which is more than double the original strength. The interaction between nanosilica and CPC was monitored using an environmental scanning electron microscope (ESEM). While hardening, nanosilica can bond to the CPC crystal network for stabilization. The physical and biological studies performed on both cements suggest that they can potentially be used in orthopedics. - Highlights: • Cement raw powder is derived from egg shells. • A microwave assisted system is used for preparing monetite bone cement. • Colloidal silica is used to reinforce cement

  14. Development of nanosilica bonded monetite cement from egg shells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Huan, E-mail: huanzhou@cczu.edu.cn [Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu (China); Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Luchini, Timothy J.F.; Boroujeni, Nariman Mansouri [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Agarwal, Anand K.; Goel, Vijay K. [Department of Bioengineering, The University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Division of Dentistry, The University of Toledo, Toledo, OH (United States)

    2015-05-01

    This work represents further effort from our group in developing monetite based calcium phosphate cements (CPC). These cements start with a calcium phosphate powder (MW-CPC) that is manufactured using microwave irradiation. Due to the robustness of the cement production process, we report that the starting materials can be derived from egg shells, a waste product from the poultry industry. The CPC were prepared with MW-CPC and aqueous setting solution. Results showed that the CPC hardened after mixing powdered cement with water for about 12.5 ± 1 min. The compressive strength after 24 h of incubation was approximately 8.45 ± 1.29 MPa. In addition, adding colloidal nanosilica to CPC can accelerate the cement hardening (10 ± 1 min) process by about 2.5 min and improve compressive strength (20.16 ± 4.39 MPa), which is more than double the original strength. The interaction between nanosilica and CPC was monitored using an environmental scanning electron microscope (ESEM). While hardening, nanosilica can bond to the CPC crystal network for stabilization. The physical and biological studies performed on both cements suggest that they can potentially be used in orthopedics. - Highlights: • Cement raw powder is derived from egg shells. • A microwave assisted system is used for preparing monetite bone cement. • Colloidal silica is used to reinforce cement.

  15. Addition of Adipose-Derived Stem Cells to Mesenchymal Stem Cell Sheets Improves Bone Formation at an Ectopic Site

    Directory of Open Access Journals (Sweden)

    Zhifa Wang

    2016-02-01

    Full Text Available To determine the effect of adipose-derived stem cells (ADSCs added to bone marrow-derived mesenchymal stem cell (MSC sheets on bone formation at an ectopic site. We isolated MSCs and ADSCs from the same rabbits. We then prepared MSC sheets for implantation with or without ADSCs subcutaneously in the backs of severe combined immunodeficiency (SCID mice. We assessed bone formation at eight weeks after implantation by micro-computed tomography and histological analysis. In osteogenic medium, MSCs grew to form multilayer sheets containing many calcium nodules. MSC sheets without ADSCs formed bone-like tissue; although neo-bone and cartilage-like tissues were sparse and unevenly distributed by eight weeks after implantation. In comparison, MSC sheets with ADSCs promoted better bone regeneration as evidenced by the greater density of bone, increased mineral deposition, obvious formation of blood vessels, large number of interconnected ossified trabeculae and woven bone structures, and greater bone volume/total volume within the composite constructs. Our results indicate that although sheets of only MSCs have the potential to form tissue engineered bone at an ectopic site, the addition of ADSCs can significantly increase the osteogenic potential of MSC sheets. Thus, the combination of MSC sheets with ADSCs may be regarded as a promising therapeutic strategy to stimulate bone regeneration.

  16. Additive Effects of Mechanical Marrow Ablation and PTH Treatment on de Novo Bone Formation in Mature Adult Rats

    OpenAIRE

    Jodi A. Carlson Scholz; Agnès Vignery; James Gilligan; Nozer Mehta; Xiaoqing Xu; Christopher Miller; Jesse Bible; Jiliang Li; Qing Zhang,

    2012-01-01

    Mechanical ablation of bone marrow in young rats induces rapid but transient bone growth, which can be enhanced and maintained for three weeks by the administration of parathyroid hormone (PTH). Additionally, marrow ablation, followed by PTH treatment for three months leads to increased cortical thickness. In this study, we sought to determine whether PTH enhances bone formation after marrow ablation in aged rats. Aged rats underwent unilateral femoral marrow ablation and treatment with PTH o...

  17. Improvement of Cracking-resistance and Flexural Behavior of Cement-based Materials by Addition of Rubber,Particles

    Institute of Scientific and Technical Information of China (English)

    KANG Jingfu; JIANG Yongqi

    2008-01-01

    By ring test and bend test,the improvement of waste tire rubber particles on the crack-resistance and flexural behaviors of cement-based materials were investigated.Test results show that the cracking time of the ring specimens can be retarded by the incorporation of rubber particles in the cement paste and mortar.The improvement in the crack-resistance depended on the rubber fraction.When the rubber fraction was 20%in volume,the cracking time was retarded about 15 h for the paste and 24 d for the mortar respectively.Flexural properties were evaluated based on the bend test results for both mortar and concrete containing different amount of rubber particles.Test results show that rubberized mortar and concrete specimens exhibit ductile failure and significant deformation before fracture.The ultimate deformations of both mortar and concrete specimen increase more than 2-4 times than control specimens.

  18. 高黏度骨水泥与传统骨水泥治疗骨质疏松性椎体压缩性骨折的疗效比较%Comparison of high viscosity bone cement and traditional bone cement for osteoporotic vertebral compression fractures

    Institute of Scientific and Technical Information of China (English)

    彭昊; 谭俊峰; 刘洋; 李明辉; 陈方舟; 张觅; 郑先念

    2014-01-01

    目的:比较高黏度骨水泥与传统聚甲基丙烯酸甲酯(PMMA)骨水泥治疗骨质疏松性椎体压缩性骨折的疗效,探讨高黏度骨水泥在临床应用中的优势。方法选择2009年7月~2013年7月治疗并获得随访160例骨质疏松性椎体压缩性骨折患者,其中男性64例,女性96例;年龄61~88岁,平均年龄69.1岁。分高黏度骨水泥组[91例(112个椎体)]和传统骨水泥组[69例(86个椎体)]。高黏度骨水泥组,采用以色列Disc-O-Tech公司Confidence骨水泥,施行经皮椎体成形术(PVP);传统骨水泥组,采用PMMA骨水泥,施行PVP。术后对比两组患者视觉疼痛模拟评分(VAS)、责任椎Cobb角的恢复情况及术后骨水泥渗漏情况,并随访观察。结果高黏度骨水泥组与传统骨水泥组VAS评分(1.5±0.8 vs 1.4±0.9)比较差异无统计学意义(P >0.05);高黏度骨水泥组Cobb角恢复优于传统骨水泥组(13.6°±3.1° vs 19.8°±3.0°),差异有统计学意义(P0.05);The recovery of Cobb angle in high viscosity bone cement was superior to that in the traditional bone cement group(13.6°± 3.1° vs 19.8° ± 3.0°), the difference was statistically significant(P<0.05);The leakage rate in high viscosity bone cement was much lower than that in the traditional bone cement group (19.6%vs 41.9%), the difference was statistically significant (P<0.05). All the patients were obtained follow-up of 16 months(3-48 months). The radicular symptoms were observed in 3 patients, and no infection and pulmonary embolism occurred in all patients. Conclusion It is demonstrated that compared with traditional PMMA bone cement, high viscosity bone cement makes significant improvement in correction of Cobb angle and the reduction of cement leakage. It is increased the efficacy and safety of PVP obviously.

  19. Design and biomechanical study of bone cement injectable canulated pedicle screw%新型可注射骨水泥椎弓根螺钉的设计及生物力学研究

    Institute of Scientific and Technical Information of China (English)

    刘瑶瑶; 孙东; 罗飞; 张泽华; 代飞; 许建中

    2012-01-01

    目的 探讨一种新型可注射骨水泥椎弓根螺钉(bone cement injectable canulated pedicle screw,CICPS)的设计和生物力学性能,为骨质疏松脊柱疾病的内固定治疗提供一种安全有效的新选择. 方法 (1)在体外、骨质疏松松质骨模型和椎体标本内行骨水泥注射实验,X线片、CT观察骨水泥分布和钉-骨界面情况.(2)取10枚灌注骨水泥后的CICPS和普通椎弓根螺钉行剪切力试验.(3)在松质骨模型中用2~3ml骨水泥强化CICPS行轴向拔出力试验,与普通椎弓根螺钉进行比较. 结果 CICPS各个侧孔均有骨水泥流出,且仅分布于螺钉前部,弥散均匀广泛,未见骨水泥渗漏.CICPS的剪切力为(10600.8±360.1)N,普通螺钉为(15 458.1±311.4)N(P<0.05).CICPS的最大轴向拔出力为(209.3±13.3)N,普通螺钉为(27.0±5.0)N(P<0.05).结论 CICPS使骨水泥弥散均匀一致,减少骨水泥渗漏风险,并可显著提高骨质疏松椎体中椎弓根螺钉的把持力.CICPS具有良好的有效性和安全性,为其临床应用提供了理论基础.%Objective To investigate the design and mechanical properties of bone cement injectable canulated pedicle screw (CICPS) so as to provide a safe and effective internal fixation for osteoporotic spinal disorder. Methods ( 1 ) Bone cement injection test was performed in vitro,and within osteoporotic cancellous bone models and osteoporotic vertebrae respectively.The distribution of bone cement and screw-bone interface were observed by X-ray films and CT.(2) Ten CICPSs already injected with bone cement and ten conventional pedicle screws were respectively examined by shear strength test.(3) CICPS in the cancellous bone models was augmented with 2-3 ml of bone cement.Then,the maximum axial pull-out strength of the CICPS was measured and were compared with that of conventional screws. Results Bone cement overflowed from each side hole of the CICPS and distributed only around the front of screws in an even and extensive

  20. Biomechanical evaluation of dynamic hip screw with bone cement augmentation in normal bone%骨水泥强化正常骨质DHS固定的生物力学研究

    Institute of Scientific and Technical Information of China (English)

    黎宁; 彭阿钦; 聂喜增; 李锋; 赵永涛; 毕靖博; 韩长伶

    2008-01-01

    背景:DHS是治疗股骨转子间骨折的标准内固定,对于伴有骨质疏松的骨折,容易发生拉力螺钉切割.国内外文献建议骨水泥强化DHS以达到坚强内固定,但是对于正常骨质,骨水泥强化是否有效还缺少报道.目的:选取正常骨密度的股骨转子间骨折标本,观察骨水泥强化对DHS固定的生物力学影响.设计、时间及地点:同一标本两侧对比观察实验,于2005-03/05在河北省骨科研究所生物力学实验室完成.材料:选取河北医科大学解剖教研室提供的成年男性防腐尸体双侧股骨上段标本.X射线证实无结核、畸形、肿瘤.方法:取成年男性防腐尸体双侧股骨上段标本24对48侧,制备A2型股骨转子间骨折模型.右侧标本行骨水泥强化DHS固定(在股骨头近端钉道用刮匙扩大.股骨头朝下,注入2mL低黏稠度骨水泥,拧入拉力螺钉,保持位置不变直至骨水泥凝固.置入套筒,拧紧尾钉适当加压,皮质骨螺钉固定钢板),为强化组;左侧行DHS常规固定,为对照组.两组标本进行弯曲强度试验及扭转强度试验.主要观察指标:两组标本的最大负荷及最大扭矩.结果:强化组最大负荷及最大扭矩与对照组比较,差异均无统计学意义[最大负荷分别为:(3852.1602±143.6031)N和(3702.9667±133.8601)N;最大扭矩分别为(15.5±2.6)N·m,(14.7±3.4)N·m, P>0.0⑤.结论:对于正常骨密度的股骨转子间骨折,骨水泥强化对DHS固定强度及骨折整体稳定性无显著的影响.%BACKGROUND: Dynamic hip screw (DHS) is a standard internal fixation for intertrochanteric fracture, whereas the patient combined with osteoporosis, cut-out incidence of lag screw is common. The articles in China and abroad indicate bone cement augmentation of DHS to achieve firm fixation. As for normal bone, no reports is published that whether bone cement augmentation is effective.OBJECTIVE: To investigate the biomechanics of DHS with bone cement augmentation for

  1. MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ULTRAFINE WC/Co CEMENTED CARBIDES WITH CUBIC BORON NITRIDE AND Cr₃C₂ ADDITIONS

    OpenAIRE

    Genrong Zhang; Haiyan Chen; Dong Lihua; Yin,; Li Kun

    2016-01-01

    This study investigates the microstructure and mechanical properties of ultrafine tungsten carbide and cobalt (WC/Co) cemented carbides with cubic boron nitride (CBN) and chromium carbide (Cr₃C₂) fabricated by a hot pressing sintering process. This study uses samples with 8 wt% Co content and 7.5 vol% CBN content, and with different Cr₃C₂ content ranging from 0 to 0.30 wt%. Based on the experimental results, Cr₃C₂ content has a significant influence on inhibiting abnormal grain growth and dec...

  2. Portland cement with additives in the repair of furcation perforations in dogs Cimento Portland com aditivos na reparação de perfurações radiculares em cães

    Directory of Open Access Journals (Sweden)

    José Dias da Silva Neto

    2012-11-01

    Full Text Available PURPOSE: To evaluate the use of Portland cements with additives as furcation perforation repair materials and assess their biocompatibility. METHODS: The four maxillary and mandibular premolars of ten male mongrel dogs (1-1.5 years old, weighing 10-15 kg received endodontic treatment (n=80 teeth. The furcations were perforated with a round diamond bur (1016 HL. The perforations involved the dentin, cementum, periodontal ligament, and alveolar bone. A calcium sulfate barrier was placed into the perforated bone to prevent extrusion of obturation material into the periradicular space. The obturation materials MTA (control, white, Type II, and Type V Portland cements were randomly allocated to the teeth. Treated teeth were restored with composite resin. After 120 days, the animals were sacrificed and samples containing the teeth were collected and prepared for histological analysis. RESULTS: There were no significant differences in the amount of newly formed bone between teeth treated with the different obturation materials (p=0.879. CONCLUSION: Biomineralization occurred for all obturation materials tested, suggesting that these materials have similar biocompatibility.OBJETIVO: Avaliar o uso de cimentos Portland aditivados na reparação de perfurações radiculares e a biocompatibilidade destes materiais. MÉTODOS: Oitenta pré-molares, quatro da arcada dentária superior e quatro da arcada inferior de 10 cães machos, sem raça definida, com idade em torno de um a um ano e meio, pesando entre 10 e 15 kg foram submetidos a tratamento endodôntico, sendo realizadas perfurações nas furcas com broca de diamante 1016 HL. A cavidade envolveu dentina e cemento, como também periodonto e o osso alveolar. Na porção óssea da obturação, barreira de sulfato de cálcio foi utilizada evitando extravasamento do cimento para o espaço periodontal. Foi realizada a distribuição randomizada dos cimentos MTA (controle, Portland tipo II, Portland tipo V e

  3. Current status of the application of antibiotic-loaded bone cements in primary arthroplasty%初次关节置换中抗生素骨水泥的应用现状

    Institute of Scientific and Technical Information of China (English)

    王晓楠; 王金成

    2013-01-01

    Infection is considered to be a serious complication of artificial arthroplasty. Accordingly, infection control becomes a research focus in recent years. In order to reduce its incidence, many doctors use antibiotic-loaded bone cements in primary arthroplasty, especially in those special cases, such as surgery with a long period, or with a high risk of pollution, revision surgery, and for patients with idiopathic or acquired immunodeficiency, patients with rheumatoid diseases or systemic lupus erythematosus, patients treated with radiotherapy or chemotherapy, obese patients, diabetic patients, especially patients with poor glucose control, and patients with previous joint infection or malignancy. However, there exists such problems as higher costs and a single kind of antibiotics in use. At the same time, the release time of antibiotics in bone cements is limited, which determines that the infection is mainly prevented in the introduced pathway after artificial arthroplasty. So it is uncertain whether all types of bacteria entering the human body through the introduced pathway can be included by the antibacterial spectrum of antibiotics in bone cements, and further experiments and studies are needed for doctors to verify the results. In this article, we reviewed the application of antibiotic-loaded bone cements in primary arthroplasty for reference.

  4. Progress in the related factors of vertebral refracture after bone cement augmentation%骨水泥强化术后椎体再骨折的相关因素研究进展

    Institute of Scientific and Technical Information of China (English)

    贾璞; 唐海

    2013-01-01

    With the advances in medical technology, the use of bone cement augmentation in the treatment of osteoporotic vertebral compression fractures has been widely used to get a satisfactory effect. However, refractures after bone cement augmentation have also obtained more and more attention. Nowadays, there are a lot of studies on the risk factors of vertebral refractures, including biomechanics, bone cement leakage, osteoporosis and other factors. In this paper, the related factors of vertebral refracture after bone cement augmentation were reviewed.%骨水泥强化术已被广泛用于骨质疏松性椎体压缩骨折的治疗.骨水泥强化术后椎体再骨折也受到越来越多的关注.国内外研究认为椎体再骨折的危险因素包括生物力学、骨水泥渗漏、骨质疏松等.本文就骨水泥强化术后椎体再骨折的相关因素进行综述

  5. MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ULTRAFINE WC/Co CEMENTED CARBIDES WITH CUBIC BORON NITRIDE AND Cr₃C₂ ADDITIONS

    Directory of Open Access Journals (Sweden)

    Genrong Zhang

    2016-03-01

    Full Text Available This study investigates the microstructure and mechanical properties of ultrafine tungsten carbide and cobalt (WC/Co cemented carbides with cubic boron nitride (CBN and chromium carbide (Cr₃C₂ fabricated by a hot pressing sintering process. This study uses samples with 8 wt% Co content and 7.5 vol% CBN content, and with different Cr₃C₂ content ranging from 0 to 0.30 wt%. Based on the experimental results, Cr₃C₂ content has a significant influence on inhibiting abnormal grain growth and decreasing grain size in cemented carbides. Near-full densification is possible when CBN-WC/Co with 0.25 wt% Cr₃C₂ is sintered at 1350°C and 20 MPa; the resulting material possesses optimal mechanical properties and density, with an acceptable Vickers hardness of 19.20 GPa, fracture toughness of 8.47 MPa.m1/2 and flexural strength of 564 MPa.u̇ Å k⃗

  6. Photocurable bioactive bone cement based on hydroxyethyl methacrylate-poly(acrylic/maleic) acid resin and mesoporous sol gel-derived bioactive glass.

    Science.gov (United States)

    Hesaraki, S

    2016-06-01

    This paper reports on strong and bioactive bone cement based on ternary bioactive SiO2-CaO-P2O5 glass particles and a photocurable resin comprising hydroxyethyl methacrylate (HEMA) and poly(acrylic/maleic) acid. The as-cured composite represented a compressive strength of about 95 MPa but it weakened during soaking in simulated body fluid, SBF, qua its compressive strength reached to about 20 MPa after immersing for 30 days. Biodegradability of the composite was confirmed by reducing its initial weight (~32%) as well as decreasing the molecular weight of early cured resin during the soaking procedure. The composite exhibited in vitro calcium phosphate precipitation in the form of nanosized carbonated hydroxyapatite, which indicates its bone bonding ability. Proliferation of calvarium-derived newborn rat osteoblasts seeded on top of the composite was observed during incubation at 37 °C, meanwhile, an adequate cell supporting ability was found. Consequently, it seems that the produced composite is an appropriate alternative for bone defect injuries, because of its good cell responses, high compressive strength and ongoing biodegradability, though more in vivo experiments are essential to confirm this assumption. PMID:27040248

  7. Cement Conundrum

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China aims to streamline the crowded cement industry Policymakers are looking to build a concrete wall around the cement-making industry as they seek to solidify the fluid cement market and cut excessive production.

  8. Effect of Raw Bauxite Addition on Thermal Behaviour of Ultra-low Cement Al2O3-SiO2 Castables

    Institute of Scientific and Technical Information of China (English)

    HOU Wanguo; ZHOU Ningsheng

    2009-01-01

    This work investigated the thermo-gravimetric (TG) change and explosion resistance of ultra-low cement Al2O3 -SiO2 castables added with 0, 5%, 10%, 15% and 20% of ≤74 μm raw bauxite powders containing 72. 8% Al2O3, respectively. The castables were prepared using white fused alumina as aggregate, powders of white fused alumina, fused mullite, α-Al2O3 ultrafines, 3% CA cement and 5% microsilica as the matrix portion. TG change of the castables was investi-gated by a thermo-gravimetric analyzer for large size specimen. When the raw bauxite addition is less than 10%, the mass-losing behavior of the castables is simi-lar to that without raw bauxite, tending to reach a con-stant mass around 400 ℃ , before which the mass-loss is mild and producing little destructive influence. With more than 10% raw bauxite addition, however, the mass-loss increases significantly, and the temperature to reach a constant mass increases to 600 ℃ or higher, unfavorable to structural stabilization. With the raw bauxite addition up to 20%, no negative influence on explosion resistance is found.

  9. 单纯骨水泥椎体成形治疗胸椎症状性血管瘤%Bone cement vertebroplasty for symptomatic thoracic vertebral hemangioma

    Institute of Scientific and Technical Information of China (English)

    晏雄伟; 张洪燕

    2013-01-01

    背景:自从经皮穿刺注射骨水泥椎体成形技术成功用于脊柱骨折的治疗后,一直在尝试用于椎体血管瘤的治疗。  目的:评价经皮穿刺单纯骨水泥椎体成形治疗症状性椎体血管瘤的安全性和有效性。  方法:9例胸椎症状性椎体血管瘤患者,男2例,女7例,均有背部疼痛等症状,其中2例有神经根刺激症状。采用经皮穿刺单纯骨水泥椎体成形治疗,治疗后进行临床和影像学随访。  结果与结论:操作成功率100%,均未出现肺栓塞、神经损伤等并发症,治疗后影像学检查示均无椎管内或椎间孔渗漏。治疗后24 h症状均有缓解,9例均获得随访,随访时间3-36个月,显示原有症状体征消失或基本消失,血管瘤无复发。结果可见经皮穿刺注射骨水泥椎体成形治疗症状性椎体血管瘤安全有效,它不仅可以缓解症状,还可以增加椎体的稳定性,预防压缩性骨折、防止复发。%BACKGROUND:Since percutaneous injection of bone cement vertebroplasty has been successful y used in treatment of spine fracture, percutaneous vertebroplasty is trying to be utilized in the treatment of vertebral hemangiomas. OBJECTIVE:To evaluate the safety and effectiveness of percutaneous injection of bone cement vertebroplasty in the treatment of symptomatic vertebral hemangiomas. METHODS:Total y nine patients with symptomatic thoracic vertebral hemangioma patients, including two males and seven females, had back pain. Of them, two cases suffered from nerve root irritation. Percutaneous vertebroplasty with bone cement was used alone. Postoperative clinical and radiographic fol ow-up was conducted. RESULTS AND CONCLUSION:The success rate was 100%, and no pulmonary embolism or nerve injury appeared. Postoperative imaging showed no leakage of spinal canal or foramen. At 24 hours after treatment, the symptoms had eased;nine cases were fol owed up for 3 to 36 months

  10. Fixation of non-cemented total hip arthroplasty femoral components in a simulated proximal bone defect model.

    Science.gov (United States)

    Sangiorgio, Sophia N; Ebramzadeh, Edward; Knutsen, Ashleen R; Borkowski, Sean L; Kalma, Jeremy J; Bengs, Benjamin C

    2013-10-01

    An accelerated sequential proximal femoral bone loss model was used to measure the initial stability of three noncemented femoral stem designs: fully porous-coated, proximally porous-coated, and dual-tapered, diaphyseal press-fit (N=18). Only dual-tapered, diaphyseal press-fit stems remained stable with as much as 105 mm of bone loss, with average cyclic micromotion remaining below 25 μm in ML and below 10 μm in AP planes. In contrast, with proximally coated and fully coated stem designs with circular or oval cross-sections, 60mm of bone loss, resulting in lower than 10 cm of diaphyseal bone contact length, led to gross instability, increasing average cyclic micromotions to greater than 100 μm prior to failure. Therefore, the results provide support for using a dual-tapered stem in revision cases with proximal bone loss. PMID:23523487

  11. The effect of pulsed jet lavage in vertebroplasty on injection forces of PMMA bone cement: an animal study

    OpenAIRE

    Boger, Andreas; Benneker, Lorin M.; Krebs, Jörg; Boner, Vanessa; Heini, Paul F.; Gisep, Armando

    2009-01-01

    Percutaneous vertebroplasty, comprising of the injection of polymethylmethacrylate (PMMA) into vertebral bodies, is an efficient procedure to stabilize osteoporotic compression fractures as well as other weakening lesions. Besides fat embolism, cement leakage is considered to be one of the major and most severe complications during percutaneous vertebroplasty. The viscosity of the PMMA during injection plays a key role in this context. It was shown in vitro that the best way to lower the risk...

  12. Additive Effects of Mechanical Marrow Ablation and PTH Treatment on de Novo Bone Formation in Mature Adult Rats

    Directory of Open Access Journals (Sweden)

    Jodi A. Carlson Scholz

    2012-12-01

    Full Text Available Mechanical ablation of bone marrow in young rats induces rapid but transient bone growth, which can be enhanced and maintained for three weeks by the administration of parathyroid hormone (PTH. Additionally, marrow ablation, followed by PTH treatment for three months leads to increased cortical thickness. In this study, we sought to determine whether PTH enhances bone formation after marrow ablation in aged rats. Aged rats underwent unilateral femoral marrow ablation and treatment with PTH or vehicle for four weeks. Both femurs from each rat were analyzed by X-ray and pQCT, then analyzed either by microCT, histology or biomechanical testing. Marrow ablation alone induced transient bone formation of low abundance that persisted over four weeks, while marrow ablation followed by PTH induced bone formation of high abundance that also persisted over four weeks. Our data confirms that the osteo-inducive effect of marrow ablation and the additive effect of marrow ablation, followed by PTH, occurs in aged rats. Our observations open new avenues of investigations in the field of tissue regeneration. Local marrow ablation, in conjunction with an anabolic agent, might provide a new platform for rapid site-directed bone growth in areas of high bone loss, such as in the hip and wrist, which are subject to fracture.

  13. Physical and chemical characterization of pastes of bone cements with ZrO{sub 2}; Caracterizacion fisica y quimica de pastas de cementos oseos con ZrO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Quinto H, A. [Instituto Tecnologico de Zacatepec, A.P. 45, 62900 Zacatepec, Morelos (Mexico); Pina B, M.C. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, A.P. 70-360, 04510 Mexico D.F. (Mexico)

    2003-07-01

    Setting times and temperature of sixteen calcium phosphate cements added with ZrO{sub 2} were evaluated. Their behaviors were analysed to be used like injectable formulations in surgery of bone. Two cements of calcium phosphates enriched with ZrO{sub 2} with the best characteristics in setting times and temperature, were mechanically tested after 1 and 7 days of prepared. Density was determined using a pycnometer, chemical composition was determined by X-ray diffraction and the molecular structure was determined by infrared spectroscopy. (Author)

  14. Mechanical property and in vitro biocompatibility of brushite cement modified by polyethylene glycol

    International Nuclear Information System (INIS)

    Brushite (dicalcium phosphate dihydrate, DCPD) cement, owing to its high solubility in physiological condition and ability to guide new bone formation, is widely used to treat bone defects. In the present study, we have evaluated the effects of poly ethylene glycol (PEG) addition on the setting time, compressive strength and in vitro biocompatibility of brushite cement. The brushite cements were prepared by mixing β-tricalcium phosphate [β-TCP, Ca3(PO4)2] and monocalcium phosphate monohydrate [MCPM, Ca(H2PO4)2 ⋅ H2O]. PEG was introduced at 2.0 and 5.0 wt% with the liquid. Introduction of PEG resulted in marginal increase in both initial and final setting time, however, significantly affected the compressive strength. Effects of PEG incorporation on in vitro biocompatibility of brushite cements were studied by using human fetal osteoblast cells (hFOB) cells. Field emission scanning electron microscope (FESEM) images and immunohistochemical analysis indicated that pure and PEG incorporated brushite cement facilitates cell adhesion, proliferation and differentiation. Fewer cells expressed vinculin protein with increased PEG content in the cement. Cell proliferation was found to decrease with increased PEG concentration while the cell differentiation increased with PEG content. Our results provide a better understanding of in vitro biocompatibility of PEG added brushite cements that can be used to customize the cement compositions based on application need. - Highlights: ► Setting time was not altered for brushite cement with PEG addition. ► hFOB cell proliferation was found to decrease with increased PEG concentration in brushite cement. ► Enhanced ALP activity was noticed with addition of PEG in brushite cements.

  15. Sealing ability of mineral trioxide aggregate, calcium phosphate and polymethylmethacrylate bone cements on root ends prepared using an Erbium: Yttriumaluminium garnet laser and ultrasonics evaluated by confocal laser scanning microscopy

    Directory of Open Access Journals (Sweden)

    C Sabari Girish

    2013-01-01

    Full Text Available Background: Surgical endodontic therapy comprises of exposure of the involved root apex, resection of the apical end of the root, preparation of a class I cavity, and insertion of a root end filling material. Mineral trioxide aggregate (MTA is now the gold standard among all root end filling materials. MTA is however difficult to handle, expensive and has a very slow setting reaction. Aim: (1 To compare the sealing ability of MTA, polymethylmethacrylate (PMMA bone cement and CHITRA Calcium phosphate cement (CPC when used as root end filling material using Rhodamine B dye evaluated under a confocal laser scanning microscope. (2 To compare the seal of root ends prepared using an ultrasonic retroprep tip and an Er: YAG laser using three different root end filling materials. Statistical Analysis: Statistical analysis was performed using a one-way ANOVA and a two-way ANOVA, independent samples t-test and Scheffe′s post hoc test using SPSS Version 16 for Windows. Results: All the three materials, namely MTA, PMMA BONE CEMENT and CHITRA CPC, showed microleakage. Comparison of microleakage showed maximum peak value of 0.86 mm for MTA, 0.24 mm for PMMA bone cement and 1.37 mm for CHITRA CPC. The amount of dye penetration was found to be lesser in root ends prepared using Er: YAG laser when compared with ultrasonics, but the difference was found to be not statistically significant. Conclusion: PMMA bone cement is a better material as root end filling material to prevent apical microleakage. MTA still continues to be a gold standard root end filling material showing minimum microleakage. Er: YAG laser is a better alternative to ultrasonics for root end preparations.

  16. Synthesis and characterization of cement slurries additives with epoxy resins - kinetics, thermodynamic and calorimetric analysis; Sintese e caracterizacao de pastas de cimento aditivadas com resinas epoxi - analises cineticas, termodinamicas e calorimetricas

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, A.M.G.; Andrade Junior, M.A.S.; Cestari, A.R.; Vieira, E.F.S., E-mail: macleybiane@gmail.co [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil)

    2010-07-01

    Cement has been used in the world, presenting a wide versatility. However, due to its chemical nature, it is subject to several types of chemical damages, especially for agents of acidic nature. With the purpose of increase its life-time, new cement slurries have been modified with the addition of specific additives. The objective of this work is to modify cement slurries with epoxy resins, which promote higher resistance of those materials in relation to acid attacks. Three cement slurries were synthesized with epoxy resins and a standard slurries, which was composed by cement and water. After 30 days of hydration, the samples were characterized by XDR, FTIR and thermal analysis (TG and DSC). The hydration processes of the cement slurries were studied by heat-conduction microcalorimetry. A kinetic study of HCl interaction with the new slurries were performed by the batch methodology at 25, 35, 45 e 55 deg C. It was verified that the addition of the polymers delayed the processes of hydration of the slurries, decreasing the flow of heat released as a function of the amount of added resin and, increased the resistance of those slurries to the acid attack. (author)

  17. Evaluation of compressive strength and water absorption of soil-cement bricks manufactured with addition of pet (polyethylene terephthalate wastes

    Directory of Open Access Journals (Sweden)

    João Alexandre Paschoalin Filho

    2016-04-01

    Full Text Available This paper presents the evaluation of compressive strength of soil-cement bricks obtained by the inclusion in their mixture of PET flakes through mineral water bottles grinding. The Polyethylene Terephthalate (PET has been characterized by its difficulty of disaggregation in nature, requiring a long period for this. On the other hand, with the increase in civil construction activities the demand for raw material also increases, causing considerable environmental impacts. In this context, the objective of this research is to propose a simple methodology, preventing its dumping and accumulation in irregular areas, and reducing the demand of raw materials by the civil construction industry. The results showed that compressive strengths obtained were lower than recommended by NBR 8491 (Associação Brasileira de Normas Técnicas [ABNT], 2012b at seven days of curing time. However, they may be used as an alternative solution in masonry works in order to not submit themselves to great loads or structural functions. The studied bricks also presented water absorption near to recommended values by NBR 8491 (ABNT, 2012b. Manufacturing costs were also determined for this brick, comparing it with the costs of other brick types. Each brick withdrew from circulation approximately 300 g of PET waste. Thus, for an area of 1 m2 the studied bricks can promote the withdrawal of approximately 180 beverage bottles of 2 L capacity.

  18. Bone cement infusion and complications during percutaneous vertebroplasty%经皮椎体成形过程中骨水泥注入及其并发症

    Institute of Scientific and Technical Information of China (English)

    程少丹; 莫文; 胡志俊; 徐华

    2009-01-01

    Percutaneous vertebroplasty has many advantages such as minimal trauma, simple mode of operation, rapid and correct therapeutic effect, high safety, and wide indications. Therefore it has been generally paid close attention and accepted. Percutaneous vertebroplasty has conspicuous curative effect, especially in vertebral compression fracture. Polymethyl methacrylate is the most used filling materials at present; There is not significant difference between unipedicular and bipedicular vertebroplasty; Using vertebral body venography and appropriate dense bone cement can reduce leakage of bone cement; Bolster for self-replacement can rebound vertebral body height, and balloon kyphoplasty and sky bone expander kyphoplasty can be avoided; In order to reduce refracture of vertebral body, anti-osteoporosis drugs should be used in the treatment of percutaneous vertebroplasty.%经皮椎体成肜以其创伤小、操作方式简单、疗效快且确切、安全性高、适应证广等优点,很快受到广泛关注和接受,尤其是在治疗椎体压缩性骨折方面取得了明显的疗效.聚甲基丙烯酸甲酯是目前最常用的填充物;单侧注射和双侧沣射疗效没有明显差别;应用对比剂及掌握合适的骨水泥黏稠度可以减少骨水泥的渗漏率;成形前腰部垫枕自身复位可以恢复椎体的高度,避免采用操作复杂及价格昂贵的球囊后凸成形及骨膨胀椎体后凸成形;进行经皮椎体成形时应该配合应用抗骨质疏松药物,以减少椎体再骨折的发生.

  19. Spinal Epidural Abscess with Pyogenic Arthritis of Facet Joint Treated with Antibiotic-Bone Cement Beads - A Case Report -

    OpenAIRE

    Lee, Bong-Jin; Lee, Sung-Rak; Kim, Seong-Tae; Kim, Tae-Ho; Lee, Sang-Hoon

    2007-01-01

    Most epidural abscesses are a secondary lesion of pyogenic spondylodiscitis. An epidural abscess associated with pyogenic arthritis of the facet joint is quite rare. To the best of our knowledge, there is no report of the use of antibiotic-cement beads in the surgical treatment of an epidural abscess. This paper reports a 63-year-old male who sustained a 1-week history of radiating pain to both lower extremities combined with lower back pain. MRI revealed space-occupying lesions, which were l...

  20. Cement penetration after patella venting.

    Science.gov (United States)

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

  1. Advanced cementation concepts

    International Nuclear Information System (INIS)

    The purpose of this programme of work was to investigate whether improvements could be made to existing formulations for cement suitable for the immobilization of intermediate level radioactive waste. Two additives were selected, microsilica and limestone flour. Improvements to the cement were only slight. (author)

  2. Reaction kinetics of dual setting α-tricalcium phosphate cements.

    Science.gov (United States)

    Hurle, Katrin; Christel, Theresa; Gbureck, Uwe; Moseke, Claus; Neubauer, Juergen; Goetz-Neunhoeffer, Friedlinde

    2016-01-01

    Addition of ductile polymers to calcium-deficient hydroxyapatite (CDHA)-forming bone cements based on α-tricalcium phosphate (α-TCP) is a promising approach to improve the mechanical performance of α-TCP cements and extend their application to load-bearing defects, which is else impeded by the brittleness of the hardened cement. One suitable polymer is poly-(2-hydroxyethylmethacrylate) (p-HEMA), which forms during cement setting by radical polymerisation of the monomer. In this study the hydration kinetics and the mechanical performance of α-TCP cements modified with addition of different HEMA concentrations (0-50 wt% in the cement liquid) was investigated by quantitative in situ XRD and four-point bending tests. Morphology of CDHA crystals was monitored by scanning electron microscopy. The hydration of α-TCP to CDHA was increasingly impeded and the visible crystal size of CDHA increasingly reduced with increasing HEMA concentration. Modification of the cements by adding 50 wt% HEMA to the cement liquid changed the brittle performance of the hardened cement to a pseudoplastic behaviour, reduced the flexural modulus and increased the work of fracture, while lower HEMA concentrations had no significant effect on these parameters. In such a composite, the extent of CDHA formation was considerably reduced (34.0 ± 1.8 wt% CDHA with 50 % HEMA compared to 54.1 ± 2.4 wt% CDHA in the reference formed after 48 h), while the general reaction kinetics were not changed. In conclusion, while the extent of CDHA formation was decreased, the mechanical properties were noticeably improved by addition of HEMA. Hence, α-TCP/HEMA composites might be suitable for application in some load-bearing defects and have adequate properties for mechanical treatment after implantation, like insertion of screws. PMID:26610924

  3. Virtopsy -- noninvasive detection of occult bone lesions in postmortem MRI: additional information for traffic accident reconstruction.

    Science.gov (United States)

    Buck, Ursula; Christe, Andreas; Naether, Silvio; Ross, Steffen; Thali, Michael J

    2009-05-01

    In traffic accidents with pedestrians, cyclists or motorcyclists, patterned impact injuries as well as marks on clothes can be matched to the injury-causing vehicle structure in order to reconstruct the accident and identify the vehicle which has hit the person. Therefore, the differentiation of the primary impact injuries from other injuries is of great importance. Impact injuries can be identified on the external injuries of the skin, the injured subcutaneous and fat tissue, as well as the fractured bones. Another sign of impact is a bone bruise. The bone bruise, or occult bone lesion, means a bleeding in the subcortical bone marrow, which is presumed to be the result of micro-fractures of the medullar trabeculae. The aim of this study was to prove that bleeding in the subcortical bone marrow of the deceased can be detected using the postmortem noninvasive magnetic resonance imaging. This is demonstrated in five accident cases, four involving pedestrians and one a cyclist, where bone bruises were detected in different bones as a sign of impact occurring in the same location as the external and soft tissue impact injuries. PMID:19034476

  4. Osteogenic capacity of nanocrystalline bone cement in a weight-bearing defect at the ovine tibial metaphysis

    Directory of Open Access Journals (Sweden)

    Mittlmeier T

    2012-06-01

    Full Text Available Christoph Harms,1 Kai Helms,1 Tibor Taschner,1 Ioannis Stratos,1 Anita Ignatius,5 Thomas Gerber,2 Solvig Lenz,3 Stefan Rammelt,6 Brigitte Vollmar,4 Thomas Mittlmeier11Department of Trauma and Reconstructive Surgery, 2Department for Materials Research and Nanostructures, Institute for Physics, 3Department of Oral and Maxillofacial Plastic Surgery, 4Institute for Experimental Surgery, University of Rostock, Rostock, 5Institute of Orthopaedic Research and Biomechanics, University of Ulm, Ulm, 6Clinic of Trauma and Reconstructive Surgery, University Hospital "Carl Gustav Carus", Dresden, GermanyAbstract: The synthetic material Nanobone® (hydroxyapatite nanocrystallines embedded in a porous silica gel matrix was examined in vivo using a standardized bone defect model in the ovine tibial metaphysis. A standardized 6 × 12 × 24-mm bone defect was created below the articular surface of the medial tibia condyles on both hind legs of 18 adult sheep. The defect on the right side was filled with Nanobone®, while the defect on the contralateral side was left empty. The tibial heads of six sheep were analyzed after 6, 12, and 26 weeks each. The histological and radiological analysis of the defect on the control side did not reveal any bone formation after the total of 26 weeks. In contrast, the microcomputed tomography analysis of the defect filled with Nanobone® showed a 55%, 72%, and 74% volume fraction of structures with bone density after 6, 12, and 26 weeks, respectively. Quantitative histomorphological analysis after 6, and 12 weeks revealed an osteoneogenesis of 22%, and 36%, respectively. Hematoxylin and eosin sections demonstrated multinucleated giant cells on the surface of the biomaterial and resorption lacunae, indicating osteoclastic resorptive activity. Nanobone® appears to be a highly potent bone substitute material with osteoconductive properties in a loaded large animal defect model, supporting the potential use of Nanobone® also in

  5. Bone scanning a useful addition in the diagnosis of ankle joint trauma

    International Nuclear Information System (INIS)

    A retrospective study of the indication in 169 scintigraphic examinations of the ankle joint was made. Usually joints respond to trauma with a generalized increase of the concentration of the radiopharmaceutical. By using a highly performed technique the focal hot spot caused by the fracture can be seen in the bone scan. The focal accumulation of the radioactive material must not correspond to a bone fracture in any case. The ligamentous avulsion of a bone chip and/or the periosteum can yield the same image but it cannot be diagnosed by radiographic techniques. Initially the routine radiograph and even the tomograph often are interpreted as normal or equivocal. In these cases of ankle trauma bone scanning completes the clinical evaluation. Although bone scanning is very important in the diagnosis of any traumatic lesion of the ankle joints it cannot replace the conventional X-ray technique. (orig.)

  6. Bone cement implantation during percutaneous vertebroplasty for the treatment of thoracolumbar vertebral fractures%骨水泥植入经皮椎体成形治疗胸腰椎体骨折

    Institute of Scientific and Technical Information of China (English)

    柳申鹏; 刘中何; 赵斌; 徐海斌

    2012-01-01

    BACKGROUND: In recent years, percutaneous vertebroplasty as a safe and effective minimally invasive surgery has been widely used in the treatment of osteoporotic compression fractures and vertebral tumor-induced osteolytic bone destruction, and has obtained satisfactory results. OBJECTIVE: To explore the correlation between bone cement and the curative effect of thoracolumbar vertebral fractures by percutaneous vertebroplasty. METHODS: The VIP database and PubMed database were used to search the articles related to the clinical research of percutaneous vertebroplasty and bone cement implantation with the key words of "pereutaneous vertebroplasty, PVP, thoracic vertebra, lumbar vertebra, vertebral fracture, bone cement" in Chinese and English, respectively. A total of 22 articles were included to review. Forty cases (56 vertabral bodies) with the pain induced by thoracolumbar vertebral fractures were selected from the Department of Orthopedics, the First Affiliated Hospital of Xinxiang Medical University for the clinical validation. The percutaneous vertebroplasty was completed under the guidance of C-arm X-ray machine. The improvement of pain was observed after surgery, and the occurrence of the complications was analyzed. RESULTS AND CONCLUSION: At present, the commonly used pereutaneous vertebroplasty bone cement includes polymethyl methacrylate bone cement, calcium phosphate cement and calcium sulfate bone cement. The volume and the composition of bone cement required for the sufficient stability of fracture healing and prevention of pain is remains unclear, but we should try to use small doses of bone cement and make the bone cement evenly distributed. Meanwhile, we should select an appropriate injection method based on different situations of the vertebra in order to prevent the leakage of bone cement and new vertebral fractures. The clinical validation results show that percutaneous vertebroplasty is an effective analgesic method, and postoperative follow

  7. 骨水泥和纳米骨浆强化椎弓根螺钉植入固定骨质疏松椎体的生物力学特点%Bone cement and nano bone putty strengthen pedicle screw implantation in the fixation of osteoporotic vertebral body:biomechanical characteristics

    Institute of Scientific and Technical Information of China (English)

    卢小兵; 孟祥翔

    2015-01-01

    BACKGROUND:Nano bone putty and bone cement injection are two common methods to strengthen the fixation of pedicle screws, but there are relatively few reports on the comparison of their strengthening effects. OBJECTIVE:To compare the biomechanical characteristics of bone cement and nano bone putty strengthening pedicle screw implantation in the fixation of osteoporotic vertebral body. METHODS: Totaly 24 human cadaveric pedicles were obtained, which were al in line with osteoporosis standards, and randomly divided into 3 groups: control group (only implanted pedicle screws), bone cement group (first injected bone cement in the nail channel, and then implanted pedicle screws) and nano bone putty group (first injected nano bone putty in the nail channel, and then implanted pedicle screws). After 2 hours of implantation, the maximum axial pulout strength and the maximum rotation torque of specimens in each group were determined. RESULTS AND CONCLUSION:The maximum axial pulout strength and maximum rotation torque of the bone cement and the nano bone putty groups were greater than those of the control group (P < 0.05), and the maximum axial pulout strength and the maximum rotation torque of the bone cement group were greater than those of the nano bone putty group (P < 0.05). These results demonstrate that the maximum axial pulout strength and the maximum rotation torque of pedicle screw implantation in the fixation of osteoporotic vertebral body can be effectively improved by injection of bone cement and nano bone putty, and the strengthening effect of bone cement is more obvious. %背景:纳米骨浆和骨水泥注入是强化椎弓根螺钉固定的两种常用方法,但目前关于两种加强方法的强化效果比较的报道相对较少。目的:对比骨水泥或纳米骨浆强化椎弓根螺钉植入固定骨质疏松椎体的生物力学特点。方法:取24个人尸体椎弓根,均符合骨质疏松标准,随机均分为3组,对照组仅植

  8. Continuous Digital Light Processing (cDLP): Highly Accurate Additive Manufacturing of Tissue Engineered Bone Scaffolds.

    Science.gov (United States)

    Dean, David; Jonathan, Wallace; Siblani, Ali; Wang, Martha O; Kim, Kyobum; Mikos, Antonios G; Fisher, John P

    2012-03-01

    Highly accurate rendering of the external and internal geometry of bone tissue engineering scaffolds effects fit at the defect site, loading of internal pore spaces with cells, bioreactor-delivered nutrient and growth factor circulation, and scaffold resorption. It may be necessary to render resorbable polymer scaffolds with 50 μm or less accuracy to achieve these goals. This level of accuracy is available using Continuous Digital Light processing (cDLP) which utilizes a DLP(®) (Texas Instruments, Dallas, TX) chip. One such additive manufacturing device is the envisionTEC (Ferndale, MI) Perfactory(®). To use cDLP we integrate a photo-crosslinkable polymer, a photo-initiator, and a biocompatible dye. The dye attenuates light, thereby limiting the depth of polymerization. In this study we fabricated scaffolds using the well-studied resorbable polymer, poly(propylene fumarate) (PPF), titanium dioxide (TiO(2)) as a dye, Irgacure(®) 819 (BASF [Ciba], Florham Park, NJ) as an initiator, and diethyl fumarate as a solvent to control viscosity. PMID:23066427

  9. Cement embolism into the venous system after pedicle screw fixation: case report, literature review, and prevention tips

    Directory of Open Access Journals (Sweden)

    Ghassan Kerry

    2013-09-01

    Full Text Available The strength of pedicle screws attachment to the vertebrae is an important factor affecting their motion resistance and long term performance. Low bone quality, e.g. in osteopenic patients, keeps the screw bone interface at risk for subsidence and dislocation. In such cases, bone cement could be used to augment pedicle screw fixation. But its use is not free of risk. Therefore, clinicians, especially spine surgeons, radiologists, and internists should become increasingly aware of cement migration and embolism as possible complications. Here, we present an instructive case of cement embolism into the venous system after augmented screw fixation with fortunately asymptomatic clinical course. In addition we discuss pathophysiology and prevention methods as well as therapeutic management of this potentially life-threatening complication in a comprehensive review of the literature. However, only a few case reports of cement embolism into the venous system were published after augmented screw fixation.

  10. Effect of cementing technique and cement type on thermal necrosis in hip resurfacing arthroplasty - a numerical study

    NARCIS (Netherlands)

    Janssen, D.; Srinivasan, P.; Scheerlinck, T.; Verdonschot, N.J.J.

    2012-01-01

    Femoral fractures within resurfacing implants have been associated with bone necrosis, possibly resulting from heat generated by cement polymerization. The amount of heat generated depends on cement mantle volume and type of cement. Using finite element analysis, the effect of cement type and volume

  11. 骨水泥强化治疗骨质疏松症伴脊柱侧弯疗效分析%Effects of pedicle screw fixation with bone cement tract augmentation on scoliolosis accompanying osteoporosis

    Institute of Scientific and Technical Information of China (English)

    丁金勇; 洪少勇; 晋大祥; 梁德; 江晓兵

    2012-01-01

    incision infection,or no screw rod breakage, screw extraction,loosening,pseudoarticulation formation were found. The postoperative Cobb's angle in coronal plane was significantly lower than preoperative angle (P<0. 05),and lordosis angle in sagittal plane was significantly higher than preoperative angle(P<0.05)In addition, the post-operative ODI score was remarkably lower than preoperative score (P<0.05). Conclusion Degenerative scoliolosis accompanying by osteoporosis were well and long time retained of spine balance by part or full laminectomy and posterior long segment pedicle screw/rod internal fixation system by augmentation and restoration with bone cement in the screw tract and posterolateral spinal or intervertebral fusion.

  12. Effect of Selected Alternative Fuels and Raw Materials on the Cement Clinker Quality

    Directory of Open Access Journals (Sweden)

    Strigáč Július

    2015-11-01

    Full Text Available The article deals with the study of the effects of alternative fuels and raw materials on the cement clinker quality. The clinker quality was expressed by the content of two principal minerals alite C3S and belite C2S. The additions of alternative fuels ashes and raw materials, in principle, always increased the belite content and conversely reduced the amount of alite. The alternative fuels with high ash content were used such as the meat-bone meal, sewage sludge from sewage treatment plants and paper sludge and the used alternative raw materials were metallurgical slags - granulated blastfurnace slag, air cooled blastfurnace slag and demetallized steel slag, fluidized bed combustion fly ash and waste glass. Meat-bone meal, sewage sludge from sewage treatment plants and paper sludge were evaluated as moderately suitable alternative fuels which can be added in the amounts of 2.8 wt. % addition of meat-bone meals ash, 3.64 wt. % addition of sewage sludge ash and 3.8 wt. % addition of paper sludge ash to the cement raw mixture. Demetallised steel slag is suitable for production of special sulphate resistant cement clinker for CEM I –SR cement with addition up to 5 wt. %. Granulated blastfurnace slag is a suitable alternative raw material with addition 4 wt. %. Air cooled blastfurnace slag is a suitable alternative raw material with addition 4.2 wt. %. Waste glass is not very appropriate alternative raw material with addition only 1.16 wt. %. Fluidized bed combustion fly ash appears not to be equally appropriate alternative raw material for cement clinker burning with less potential utilization in the cement industry and with addition 3.41 wt. %, which forms undesired anhydrite CaSO4 in the cement clinker.

  13. Assessment of the value of anorganic bone additives in sinus floor augmentation: a review of clinical reports.

    NARCIS (Netherlands)

    Merkx, M.A.W.; Maltha, J.C.; Stoelinga, P.J.W.

    2003-01-01

    In order to objectively assess the value of anorganic bone additives in sinus floor augmentation, a review of the English literature till May 2002 was carried out. The studies or parts of studies had to include at the least two patients, with a follow-up of at least 3 months, whilst histomorphometri

  14. Bone regeneration effect after the addition of a vitamin complex in two bio ceramics

    International Nuclear Information System (INIS)

    One of the goals of the Biomaterials research is the development of devices that help bone regeneration. Two synthetic ceramics has been widely used with that purpose: hydroxyapatite (HAp) and beta tricalcium phosphate (β-TCP). In many situations it is desirable that the resorption rate of these materials by the body matches the bone growth rate. In these cases, the use of a mixture between the two phases is beneficial. The material resorption and bone growth are complexes physiological processes, influenced amongst other things by the inflammatory response of the surgical site. That being said, an exacerbated inflammatory response is potentially hazardous, since it may induce an increase of the oxidative stress due to the free radicals production. The free radicals attack causes, amongst other hazardous effects, the cell membrane degeneration which in turn may lead to cell necrosis and/or apoptosis within the surgical site. In this work, two ceramics were implanted in rats femora: β-TCP or the biphasic mixture of 60:40% in mass of HAp:β-TCP. The bone growth was assessed by both optical and fluorescence microscopy, using fluorescent bone markers. Moreover, it was also evaluated the effect of the presence of a vitamin complex, mediator of the inflammatory response. It was concluded that the pure β-TCP was more readily absorbed when compared with the mixture β-TCP-HAp, and there it was signs that the presence of the vitamin complex may have helped in a favorable way the bone neo formation. (author)

  15. Fabrication of an Interlocked Antibiotic/Cement-Coated Carbon Fiber Nail for the Treatment of Long Bone Osteomyelitis.

    Science.gov (United States)

    Mauffrey, Cyril; Butler, Nathan; Hake, Mark E

    2016-08-01

    Successful management of intramedullary long bone osteomyelitis remains a challenge for both surgeons and patients. Patients are often immune compromised and have endured multiple surgeries. Treatment principles include antibiotic administration (systemically ± locally), surgical debridement of the infection site, and stabilization. Since their description in 2002, antibiotic-coated nails have become part of the armamentarium for the treatment of osteomyelitis allowing both local elution of antibiotics and stabilization of a debrided long bone. Limitations to their utilization have remained, in part from the technical difficulty of fabrication and magnetic resonance imaging artifacts. We describe a new surgical technique of fabrication that has the advantages of being simple, reproducible, with an end product free of magnetic resonance imaging artifacts. PMID:27441930

  16. THE EFFECT OF NANO-TITANIA ADDITION ON THE PROPERTIES OF HIGH-ALUMINA LOW-CEMENT SELF-FLOWING REFRACTORY CASTABLES

    Directory of Open Access Journals (Sweden)

    Sasan Otroj

    2011-12-01

    Full Text Available The self-flow characteristics and properties of high-alumina low-cement refractory castables added with nano-titania particles are investigated. For this reason, the reactive alumina in the castable composition is substituted by nano-titania powder in 0-1 %wt. range. The microstructures, phase composition, physical and mechanical properties of these refractory castables at different temperatures are studied. The results show that the addition of nano-titania particles has great effect on the self-flow characteristics, phase composition, physical and mechanical properties of these refractory castables. With increase of nano-titania particles in castable composition, the self-flow value and working time tend to decrease. With addition of 0.5 wt.% nano-titania in the castable composition, the mechanical strength of castable in all firing temperatures tends to increase. It is attributed to the formation of CA6 phase and enhanced ceramic bonding. Nano-titania particles can act as a nucleating agent for hibonite phase and decrease the formation temperature of hibonite. Because of perovskite phase formation, the addition of 1 wt.% nano-titania can decrease the mechanical strength of castable after firing.

  17. Effect of pore size on bone ingrowth into porous titanium implants fabricated by additive manufacturing: An in vivo experiment.

    Science.gov (United States)

    Taniguchi, Naoya; Fujibayashi, Shunsuke; Takemoto, Mitsuru; Sasaki, Kiyoyuki; Otsuki, Bungo; Nakamura, Takashi; Matsushita, Tomiharu; Kokubo, Tadashi; Matsuda, Shuichi

    2016-02-01

    Selective laser melting (SLM) is an additive manufacturing technique with the ability to produce metallic scaffolds with accurately controlled pore size, porosity, and interconnectivity for orthopedic applications. However, the optimal pore structure of porous titanium manufactured by SLM remains unclear. In this study, we evaluated the effect of pore size with constant porosity on in vivo bone ingrowth in rabbits into porous titanium implants manufactured by SLM. Three porous titanium implants (with an intended porosity of 65% and pore sizes of 300, 600, and 900μm, designated the P300, P600, and P900 implants, respectively) were manufactured by SLM. A diamond lattice was adapted as the basic structure. Their porous structures were evaluated and verified using microfocus X-ray computed tomography. Their bone-implant fixation ability was evaluated by their implantation as porous-surfaced titanium plates into the cortical bone of the rabbit tibia. Bone ingrowth was evaluated by their implantation as cylindrical porous titanium implants into the cancellous bone of the rabbit femur for 2, 4, and 8weeks. The average pore sizes of the P300, P600, and P900 implants were 309, 632, and 956μm, respectively. The P600 implant demonstrated a significantly higher fixation ability at 2weeks than the other implants. After 4weeks, all models had sufficiently high fixation ability in a detaching test. Bone ingrowth into the P300 implant was lower than into the other implants at 4weeks. Because of its appropriate mechanical strength, high fixation ability, and rapid bone ingrowth, our results indicate that the pore structure of the P600 implant is a suitable porous structure for orthopedic implants manufactured by SLM. PMID:26652423

  18. Influence of additives for concrete on the containment of radio-elements and strength under radiation of 'cement' matrices

    International Nuclear Information System (INIS)

    In order to improve the durability of cement-based materials used for the storage of radioactive wastes, fluidizers are generally introduced into these materials during their preparation. Thus, Naphtalene Sulfonate Formaldehyde (NSF) and Melamine Sulfonate Formaldehyde (MSF) are used as fluidizers in concrete which therefore presents good rheological properties when fresh, and a high compactness when hardened. This research study aims at investigating what happens to the fluidizer in a hardened cement paste, how this fluidizer affects the durability (mechanical strength, porosity, apparent diffusion coefficient) of a cement paste in absence of irradiation, what is the behaviour of these organic compounds under irradiation (reticulation or degradation, nature of radiolysis gases), how these organic compounds affects the durability (dimension, porosity, mechanical strength) of a cement paste under cobalt 60 gamma radiation, and how apparent solubilities of the different isotopes vary in cement water in presence of these organic compounds

  19. Acute intraoperative reactions during the injection of calcium sulfate bone cement for the treatment of unicameral bone cysts: a review of four cases.

    Science.gov (United States)

    Nystrom, Lukas; Raw, Robert; Buckwalter, Joseph; Morcuende, Jose A

    2008-01-01

    Unicameral bone cysts can predispose patients to pathologic fracture and deformities of growth. Treatment options vary from continuous decompression with transcortical placement of a cannulated screw to percutaneous aspiration and injection of medical-grade calcium sulfate. From 2005 to 2007, we treated 22 patients with unicameral bone cysts using aspiration and injection of calcium sulfate. Three patients experienced acute laryngospasm and one patient developed tachyarrhythmia, temporarily, associated with injection of calcium sulfate. All reactions occurred in patients under age 18 without predisposing risk factors and resolved spontaneously with supportive care. Although the mechanism is unclear, we hypothesize that these reactions are either due to the nociceptive stimulus of the calcium sulfate injection or a systemic calcium bolus. Clinicians using this product for this indication should be aware that such reactions may occur. We suggest endotracheal intubation and communication to the anesthesiologist about the time of the injection in preparation for these idiopathic responses. Further research is necessary to determine exactly how this reaction occurs and how it can be avoided. PMID:19223954

  20. CPC/PMMA双向骨水泥性能及生物相容性的初步研究%Preliminary study on properties and biocompatibility of CPC/PMMA dual-phase bone cement

    Institute of Scientific and Technical Information of China (English)

    包利; 唐海; 王炳强; 朱富强; 董益鹏; 邓介超

    2012-01-01

    Objective To develop an injective mixture of bone cement made with polymethylmethacrylate cement ( PMMA) and calcium phosphate cement ( CPC) and to become an ideal filling material for vertebroplasty and kyphoplasty based on the advantages of each material. Methods The experimental materials were injective bone cement PMMA and CPC. Firstly, the combined bone cement was made using the different mass ratio of PMMA and CPC, 1:2, 1:1, or2:1. Secondly, the standard test pieces with 6mm in diameter and 12mm in hight were made using the combined bone cement. Finally, a preliminary evaluation of physical and chemical properties of the mixed bone cement was carried out, I. E. , mechanical property, solidification temperature, solidification time, electron microscope scanning, X-ray diffraction, and animal muscle implantation experiment. Results The mixed bone cement (1: 1) had better physical and chemical properties than other proportions. Its compressive strength increased by about 120% higher than that of CPC. The solidification temperature was lower than 45℃ , and solidification time was about 12-14 min. The microscopic structure of this mixed bone cement (1: 1) was similar to that of CPC. Seventy percent of the total pores were between 100-300μm and eyelet penetrations between the pores was mainly 10-20μm. The results of animal intramuscular implantation experiment demonstrated that the mixed bone cement (1: 1 ) had good biocompatibility, but the degeneration speed was slow. Conclusion The mixed bone cement (1:1) can overcome the shortcomings of PMMA and CPC and have the advantage of each material. So this mixed bone cement is an ideal filling material for vertebroplasty and kyphoplasty.%目的 将聚甲基丙烯酸甲酯骨水泥(PMMA)与磷酸钙骨水泥(CPC)制成一种注射型混合骨水泥,利用各自的特性,优势互补,从而使该混合骨水泥成为理想的椎体成形术及椎体后凸成形术填充材料.方法 实验材料为注射型PMMA骨水

  1. Cement Formation

    DEFF Research Database (Denmark)

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten;

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including an...... overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid...

  2. The novel fluid loss additive HTF-200C for oil field cementing%新型固井降失水剂HTF-200C

    Institute of Scientific and Technical Information of China (English)

    郭锦棠; 卢海川; 刘硕琼; 靳建州; 于永金

    2012-01-01

    The domestic fluid loss additives often have lower thermal stability and poor salt-tolerance and their comprehensive properties are not good enough. To solve the problems, a novel cement fluid loss additive HTF-200C. Which can resist high temperature and high salt content, was synthesized using the monomers of 2-acrylamido-2-methyl-propane sulphonic acid (AMPS), N, N-dimethyl acrylamide (DMAA) and a new compound with double carboxyl by the method of aqueous solution polymerization. The microstructural characterization and application performance of HTF-200C show that the polymer with the structure of all the monomers has an excellent thermal stability and strong salt tolerance, and can be used in 200 "C or in saturated brine. And the problem of the normal fluid loss additive being easy to hydrolyze due to high temperature can be solved with HTF-200C. What's more, it can also deal with the bulge of thickening curve in consistency test. The cement slurry prepared mainly by HTF-200C presents good comprehensive properties such as low filtration, high thermal stability, strong salt tolerance, rapid development of strength in low temperature, without far delayed solidification, short transit time during thickening process, and so on. The cementing job quality of Well Chengu 1-3 in the Liaohe Oilfield is excellent after it is used.%针对目前中国常规固井降失水剂抗温抗盐能力差、综合性能欠佳的问题,以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、N,N-二甲基丙烯酰胺(DMAA)、新型双羧基化合物为单体,采用水溶液自由基聚合的方法合成了耐盐、抗高温的共聚物型固井水泥降失水剂HTF-200C.HTF-200C微观结构表征和应用性能综合评价表明,各单体成功参与聚合,共聚物热稳定性良好;该降失水剂控失水耐温可达200℃,抗盐达饱和,可解决常规降失水剂高温下易水解、稠化实验“鼓包”等问题;以HTF-200C为主剂的水泥浆体系失水量低、抗盐耐温

  3. Bone

    International Nuclear Information System (INIS)

    Bone scanning provides information on the extent of primary bone tumors, on possible metastatic disease, on the presence of osteomyelitis prior to observation of roentgenographic changes so that earlier therapy is possible, on the presence of collagen diseases, on the presence of fractures not disclosed by x-ray films, and on the evaluation of aseptic necrosis. However, the total effect and contribution of bone scanning to the diagnosis, treatment, and ultimate prognosis of pediatric skeletal diseases is, as yet, unknown. (auth)

  4. Physicochemical properties and biocompatibility of chitosan oligosaccharide/gelatin/calcium phosphate hybrid cements

    International Nuclear Information System (INIS)

    A bone substitute material was developed consisting of a chitosan oligosaccharide (COS) solution in a liquid phase and gelatin (GLT) containing calcium phosphate powder in a solid phase. The physicochemical and biocompatible properties of the hybrid cements were evaluated. The addition of COS to cement did not affect the setting time or diametral tensile strength of the hybrid cements, whereas GLT significantly prolonged the setting time and decreased the strength slightly. The setting reaction was inhibited by the addition of GLT to the initial mixture, but not by COS. However, the presence of GLT appreciably improved the anti-washout properties of the hybrid cement compared with COS. COS may promote the cement's biocompatibility as an approximate twofold increase in cell proliferation for 10% COS-containing cements was observed on day 3 as compared with the controls. The combination of GLT and COS was chosen due to the benefits achieved from several synergistic effects and for their clinical applications. Cement with 5% GLT and 10% COS may be a better choice among cements in terms of anti-washout properties and biological activity.

  5. Biological characteristics of a novel pourable pedicle bone cement%新型设计可灌注骨水泥椎弓根螺钉的生物力学特性

    Institute of Scientific and Technical Information of China (English)

    马江卫; 刘烈东; 杜耿; 高光明; 刘育

    2015-01-01

    BACKGROUND:In senile osteoporosis patients, capacity of pedicle screw fixation is relatively poor due to fragile bone substance. Currently, augmentation of pedicle screw fixation with bone cement can improve the ability of screw fixation, but bone cement leakage and difficulties in screw removal become the problem to be solved. OBJECTIVE:To develop a novel pourable pedicle bone cement and to investigate its biomechanical properties, safety and practicality, thus providing the basis for clinical treatment of osteoporosis and spinal diseases. METHODS:Six cases of complete wetting spines were colected at the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine from December 2013 to January 2015, including 42 vertebrae. Pedicle screw fixation with X-ray assisted bone cement injection (2 mL) was performed unilateraly as experimental group, and conventional pedicle screw fixation was done contralateraly as control group. Bone cement dispersion was observed in the two groups. RESULTS AND CONCLUSION:It was 3-4 minutes for bone cement to agglomerate. Injection of bone cement paste into the infusion cylinder using a syringe was more convenient. The cylinder was connected tightly with the tail-end of the screw with no leakage. The push bar could provide sufficient perfusion force. Bone cement dispersion was found in the holow part and side holes of the screw. Side holes arranged regularly, and the hole pitch was equal. Compared with the control group, the yield load and yield displacement were significantly higher in the experimental group (P < 0.05), but the ultimate strength and ultimate displacement were significantly lower in the experimental group (P < 0.05). Bone cement around the pourable cement screw dispersed regularly, which was diffused into the surround cancelous bone and integrated with adjacent bone cement mass. The axial withdrawal force was increased by 114% in the experimental group compared with the control group (P < 0.05). The maximum

  6. Polyelectrolyte addition effect on the properties of setting hydraulic cements based on calcium phosphate; Efeito da adicao de polieletrolitos sobre as propriedades de cimentos de fosfato de calcio de pega hidraulica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Luis A. dos; Oliveira, Luci C. de; Rigo, Eliana C.S.; Boschi, Anselmo Ortega [Sao Carlos Univ., SP (Brazil). Dept. de Engenharia de Materiais; Carrodeguas, Raul Gracia [Universidad de La Habana, Habana, (Cuba). Centro de Biomateriales

    1997-12-31

    In the present work the effects of the addition of some poly electrolytes (sodium alginate and poly acrylic acid) on the solubility, crystalline phases, pH and mechanical strength under compression of three calcium phosphate cements were studied. (author) 10 refs., 2 figs., 4 tabs.

  7. 13C chemical shift anisotropies for carbonate ions in cement minerals and the use of 13C, 27Al and 29Si MAS NMR in studies of Portland cement including limestone additions

    International Nuclear Information System (INIS)

    13C isotropic chemical shifts and chemical shift anisotropy parameters have been determined for a number of inorganic carbonates relevant in cement chemistry from slow-speed 13C MAS or 13C(1H) CP/MAS NMR spectra (9.4 T or 14.1 T) for 13C in natural abundance. The variation in the 13C chemical shift parameters is relatively small, raising some doubts that different carbonate species in Portland cement-based materials may not be sufficiently resolved in 13C MAS NMR spectra. However, it is shown that by combining 13C MAS and 13C(1H) CP/MAS NMR carbonate anions in anhydrous and hydrated phases can be distinguished, thereby providing valuable information about the reactivity of limestone in cement blends. This is illustrated for three cement pastes prepared from an ordinary Portland cement, including 0, 16, and 25 wt.% limestone, and following the hydration for up to one year. For these blends 29Si MAS NMR reveals that the limestone filler accelerates the hydration for alite and also results in a smaller fraction of tetrahedrally coordinated Al incorporated in the C-S-H phase. The latter result is more clearly observed in 27Al MAS NMR spectra of the cement–limestone blends and suggests that dissolved aluminate species in the cement–limestone blends readily react with carbonate ions from the limestone filler, forming calcium monocarboaluminate hydrate. -- Highlights: •13C chemical shift anisotropies for inorganic carbonates from 13C MAS NMR. •Narrow 13C NMR chemical shift range (163–171 ppm) for inorganic carbonates. •Anhydrous and hydrated carbonate species by 13C MAS and 13C(1H) CP/MAS NMR. •Limestone accelerates the hydration for alite in Portland – limestone cements. •Limestone reduces the amount of aluminium incorporated in the C-S-H phase

  8. Continuous Digital Light Processing (cDLP): Highly Accurate Additive Manufacturing of Tissue Engineered Bone Scaffolds

    OpenAIRE

    Dean, David; Wallace, Jonathan; Siblani, Ali; Wang, Martha O.; Kim, Kyobum; Mikos, Antonios G.; Fisher, John P.

    2012-01-01

    Highly accurate rendering of the external and internal geometry of bone tissue engineering scaffolds effects fit at the defect site, loading of internal pore spaces with cells, bioreactor-delivered nutrient and growth factor circulation, and scaffold resorption. It may be necessary to render resorbable polymer scaffolds with 50 μm or less accuracy to achieve these goals. This level of accuracy is available using Continuous Digital Light processing (cDLP) which utilizes a DLP® (Texas Instrumen...

  9. Addition of Fructooligosaccharides and Dried Plum to Soy-Based Diets Reverses Bone Loss in the Ovariectomized Rat

    Directory of Open Access Journals (Sweden)

    Catherine D. Johnson

    2011-01-01

    Full Text Available Dietary bioactive components that play a role in improving skeletal health have received considerable attention in complementary and alternative medicine practices as a result of their increased efficacy to combat chronic diseases. The objectives of this study were to evaluate the additive or synergistic effects of dried plum and fructooligosaccharides (FOS and to determine whether dried plum and FOS or their combination in a soy protein-based diet can restore bone mass in ovarian hormone deficient rats. For this purpose, 72 3-month-old female Sprague-Dawley rats were divided into six groups (n = 12 and either ovariectomized (Ovx, five groups or sham-operated (sham, one group. The rats were maintained on a semipurified standard diet for 45 days after surgery to establish bone loss. Thereafter, the rats were placed on one of the following dietary treatments for 60 days: casein-based diet (Sham and Ovx, soy-based diet (Ovx + soy or soy-based diet with dried plum (Ovx + soy + plum, FOS (Ovx + soy + FOS and combination of dried plum and FOS (Ovx + soy + plum + FOS. Soy protein in combination with the test compounds significantly improved whole-body bone mineral density (BMD. All test compounds in combination with soy protein significantly increased femoral BMD but the combination of soy protein, dried plum and FOS had the most pronounced effect in increasing lumbar BMD. Similarly, all of the test compounds increased ultimate load, indicating improved biomechanical properties. The positive effects of these test compounds on bone may be due to their ability to modulate bone resorption and formation, as shown by suppressed urinary deoxypyridinoline excretion and enhanced alkaline phosphatase activity.

  10. Changes in bone mineral density (BMD) around the cemented Exeter stem: a prospective study in 18 women with 5 years follow-up

    DEFF Research Database (Denmark)

    Damborg, Frank; Nissen, Nis; Jørgensen, Hans R I;

    2008-01-01

    BACKGROUND AND PURPOSE: THA changes the pattern of strain distribution in the proximal femur. We quantified the changes in BMD for 5 years after insertion of the cemented Exeter stem in women. METHODS: 18 women aged 55-79 years, undergoing unilateral THA with the cemented Exeter stem, were included...

  11. 水泥与混凝土外加剂(减水剂)适应性问题探析%Inquiry on the adaptability of cement and concrete additives

    Institute of Scientific and Technical Information of China (English)

    王庆

    2016-01-01

    With an introduction of technological and economic effects of water-reducing agent,starting from aspects of cement clinker mineral composition,gypsum compositions,alkali contents and cement fineness and so on,the thesis analyzes factors influencing cement and concrete additive adaptability,and puts forward measures of solving cement and additives adaptability problems,so as to meet the engineering demands for concrete technology performance.%介绍了减水剂的技术经济效果,从水泥熟料矿物成分、石膏成分、碱含量、水泥细度等方面,分析了影响水泥与混凝土外加剂适应性的因素,提出了解决水泥与外加剂适应性问题的措施,从而满足工程对混凝土技术性能的要求.

  12. Additional Detection of Multiple Osteomas in a Patient with Gardner's Syndrome by Bone SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woo Hyoung; Kim, Daeweung; Kim, Chang Guhn; Kim, Myoung Hyoun [Wonkwang Univ. School of Medicine, Iksan (Korea, Republic of)

    2013-12-15

    Familial adenomatous polyposis (FAP) is an autosomal dominant disorder which generally develops numerous polyps in the colon and rectum during the second decade of life. Gardner's syndrome is a variant of FAP which has multiple osteomas, dental abnormalities, and fibromas, with incidence ranging between 1 in 4,000 and 1 in 40,000, depending on the region. We present the case of a 35-year-old man referred to our department for bone scintigraphy who was shown to have multiple colon polyps and nuchal type fibroma. In this patient, planar image showed intensely increased uptakes of bone agent in the maxilla and mandible, which are typical findings of Gardner's syndrome. Single photon emission computed tomography/computed tomography (SPECT/CT) was acquired to accurately identify and locate abnormal uptakes detected on planar images. SPECT/CT showed numerous osteomas in the maxilla and mandible where intense uptakes of bone agent were seen. Mildly asymmetrical, focally increased uptake in the superomedial aspect of the left orbit on anterior planar image was shown to be a fontal sinus osteoma on SPECT/CT. Enhanced sensitivity of detecting lesions of SPECT/CT superior to planar scintigraphy has been reported in previous studies. In this report, additional osteomas of sphenoidal and ethmoidal sinuses, which were not seen on planar scintigraphy, were detected by SPECT/CT. This case emphasizes that nuclear physicians should be aware of the typical findings of bone scintigraphy for Gardner's syndrome and also that SPECT/CT could be helpful to diagnose additional lesions not seen on planar images.

  13. Use of polymethylmethacrylate to enhance screw fixation in bone.

    Science.gov (United States)

    Cameron, H U; Jacob, R; Macnab, I; Pilliar, R M

    1975-07-01

    Pull-out testing of screws inserted into cement and bone under various conditions showed that the cement-screw complex was significantly stronger when the screw was placed in soft cement and the cement was allowed to polymerize without further manipulation. When screw fixation in osteoporotic bone was reinforced with cement, the bone was the weakest component in the system. Fixation under these conditions should be enhanced by increasing the area of contact between the cement and bone. By cooling the cement to prolong its working time, it could be injected with a syringe in such a way that maximum endosteal and periosteal contact was provided. PMID:1150708

  14. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    OpenAIRE

    Nediljka Gaurina-Međimurec; Davorin Matanović; Gracijan Krklec

    1994-01-01

    During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures) and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production...

  15. Health hazards of cement dust

    International Nuclear Information System (INIS)

    ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

  16. Oil-Well Cement and C3S Hydration Under High Pressure as Seen by In Situ X-Ray Diffraction, Temperatures ;= 80 degrees C with No Additives

    Energy Technology Data Exchange (ETDEWEB)

    Jupe, Andrew C.; Wilkinson, Angus P.; Funkhouser, Garry P. (Halliburton); (GIT)

    2012-06-28

    The hydration kinetics of a white cement and batches of both Class G and H oil-well cements were examined between 0 and 60 MPa, at {le}80 C, using in situ synchrotron X-ray diffraction. This gives a continuous measure of the C{sub 3}S (Ca{sub 3}SiO{sub 5}), CH (Ca(OH){sub 2}), C{sub 4}AF (Ca{sub 2}FeAlO{sub 5}), ettringite, and other phases in the hydrating slurries. Slurries prepared from single-phase C{sub 3}S; synthetic C{sub 4}AF, and gypsum; and white cement, synthetic C{sub 4}AF and gypsum were also examined. An increasing pressure enhanced the rate of hydration for all slurries. Analysis of the data, using a kinetic model, provided rate constants that were used to obtain activation volumes for C{sub 3}S hydration. For all the cement and C{sub 3}S slurries studied, similar activation volumes were obtained (average {Delta}V{double_dagger}{sup -}-35 cm{sup 3}/mol), indicating that the presence of cement phases other than C{sub 3}S has a modest influence on the pressure dependence of C{sub 3}S hydration. An alternative analysis, using the time at which 90% of the initial C{sub 3}S remained, gave similar activation volumes. Pressure accelerated the formation of ettringite from synthetic C{sub 4}AF in the presence of gypsum. However, in slurries containing cement, the pressure dependence of C{sub 3}S hydration plays a major role in determining the pressure dependence of ettringite formation.

  17. Prevention of postmenopausal bone loss - effects of alternative administration forms of estrogens, alternative gestagens and calcium addition

    International Nuclear Information System (INIS)

    Calcium metabolism was examined in 133 healthy postmenopausal women every three months during two years of treatment with oral or percutaneous 17β-estradiol combined with different doses of calcium supplementation and/or different gestagens. Bone mineral content measured in the forearm (single photon absorptiometry), in the spine and in the total skeleton (dual photon absorptiometry) was unchanged in all estrogen-treated groups during the two years of treatment, and the responses in the groups with and without calcium supplementation and with different gestagens were not significantly different. Furthermore, the responses were independent of route of administration of the estrogen. Biochemical indices of bone turnover (serum alkaline phosphatase and fasting urinary hydroxyproline/creatinine) decreased highly significantly during estrogen treatment (p<0.001) independent of route of administration of the estrogen, of calcium supplementation, and of gestagen agent. We conclude that estrogen treatment independently of route of administration, prevents postmenopausal bone loss. The gestagen agents used here do not affect calcium metabolism, and calcium supplementation has no additive effect to estrogen therapy. (orig.)

  18. Prevention of postmenopausal bone loss - effects of alternative administration forms of estrogens, alternative gestagens and calcium addition

    Energy Technology Data Exchange (ETDEWEB)

    Riis, B.J.; Christiansen, C.

    1987-02-01

    Calcium metabolism was examined in 133 healthy postmenopausal women every three months during two years of treatment with oral or percutaneous 17..beta..-estradiol combined with different doses of calcium supplementation and/or different gestagens. Bone mineral content measured in the forearm (single photon absorptiometry), in the spine and in the total skeleton (dual photon absorptiometry) was unchanged in all estrogen-treated groups during the two years of treatment, and the responses in the groups with and without calcium supplementation and with different gestagens were not significantly different. Furthermore, the responses were independent of route of administration of the estrogen. Biochemical indices of bone turnover (serum alkaline phosphatase and fasting urinary hydroxyproline/creatinine) decreased highly significantly during estrogen treatment (p<0.001) independent of route of administration of the estrogen, of calcium supplementation, and of gestagen agent. We conclude that estrogen treatment independently of route of administration, prevents postmenopausal bone loss. The gestagen agents used here do not affect calcium metabolism, and calcium supplementation has no additive effect to estrogen therapy.

  19. Effect of ZrO2 addition on the mechanical properties of porous TiO2 bone scaffolds.

    Science.gov (United States)

    Tiainen, Hanna; Eder, Georg; Nilsen, Ola; Haugen, Håvard J

    2012-08-01

    This study aimed at the investigation of the effect of zirconium dioxide (ZrO2) addition on the mechanical properties of titanium dioxide (TiO2) bone scaffolds. The highly biocompatible TiO2 has been identified as a promising material for bone scaffolds, whereas the more bioinert ZrO2 is known for its excellent mechanical properties. Ultra-porous TiO2 scaffolds (>89% porosity) were produced using polymer sponge replication with 0-40 wt.% of the TiO2 raw material substituted with ZrO2. Microstructure, chemical composition, and pore architectural features of the prepared ceramic foams were characterised and related to their mechanical strength. Addition of 1 wt.% of ZrO2 led to 16% increase in the mean compressive strength without significant changes in the pore architectural parameters of TiO2 scaffolds. Further ZrO2 additions resulted in reduction of compressive strength in comparison to containing no ZrO2. The appearance of zirconium titanate (ZrTiO4) phase was found to hinder the densification of the ceramic material during sintering resulting in poor intergranular connections and thus significantly reducing the compressive strength of the highly porous ceramic foam scaffolds. PMID:24364936

  20. Bone cement and bone grafting in nail path to strengthen dynamic hip screw fixation for senile osteoporotic intertrochanteric fracture%骨水泥、钉道植骨强化动力髋螺钉固定修复老年骨质疏松性股骨转子间骨折

    Institute of Scientific and Technical Information of China (English)

    林周胜; 孙鸿涛; 夏雄智; 江成; 黎飞猛

    2015-01-01

    背景:对于老年骨质疏松性髋部骨折的动力髋螺钉固定,如能避免使用过程中造成的骨量丢失,或是采用其他手段增加固定螺钉把持力,将改善动力髋螺钉固定的治疗效果。目的:对比研究3种固定方式修复老年骨质疏松性股骨转子间骨折的效果。方法:回顾性分析近5年来采用常规动力髋螺钉内固定、骨水泥强化后动力髋螺钉固定及主钉道压配植骨配合动力髋螺钉固定3种固定方式治疗老年骨质疏松性股骨转子间骨折患者的资料,分别设为对照组、骨水泥组和植骨组。结果与结论:经固定后2年随访,植骨组、骨水泥组和对照组Harris髋关节功能评分优良率分别为95%,80%,70%。植骨组骨折临床愈合时间明显缩短(P <0.05),出现螺钉固定失败情况与骨水泥组相当。对照组较其他2组相对更多出现退钉等内固定失败情况。结果表明,与其他常规动力髋螺钉内固定、骨水泥强化后动力髋螺钉固定方式相比较,主钉道压配植骨配合动力髋螺钉内固定的疗效及安全性更好。%BACKGROUND:In dynamic hip screw fixation for treating aged osteoporotic intertrochanteric fracture, avoiding the loss of bone mass, or by other means that can increase the fixed screw pulout strength, wil improve the therapeutic effect of dynamic hip screw fixation. OBJECTIVE: To compare the effects of three kinds of repair methods on aged osteoporotic intertrochanteric fracture. METHODS:Data of aged osteoporosis intertrochanteric fracture patients, who received conventional dynamic hip screw fixation, bone cement augmentation with dynamic hip screw fixation and bone grafting with dynamic hip screw fixation, were retrospectively analyzed. They were divided into control group, bone cement group and bone grafting group. RESULTS AND CONCLUSION:After two years of folow-up, the excelent and good rates of Harris hip function were 95%, 80% and 70% in

  1. Numerical investigation of the mechanical properties of the additive manufactured bone scaffolds fabricated by FDM: The effect of layer penetration and post-heating.

    Science.gov (United States)

    Naghieh, S; Karamooz Ravari, M R; Badrossamay, M; Foroozmehr, E; Kadkhodaei, M

    2016-06-01

    In recent years, thanks to additive manufacturing technology, researchers have gone towards the optimization of bone scaffolds for the bone reconstruction. Bone scaffolds should have appropriate biological as well as mechanical properties in order to play a decisive role in bone healing. Since the fabrication of scaffolds is time consuming and expensive, numerical methods are often utilized to simulate their mechanical properties in order to find a nearly optimum one. Finite element analysis is one of the most common numerical methods that is used in this regard. In this paper, a parametric finite element model is developed to assess the effects of layers penetration׳s effect on inter-layer adhesion, which is reflected on the mechanical properties of bone scaffolds. To be able to validate this model, some compression test specimens as well as bone scaffolds are fabricated with biocompatible and biodegradable poly lactic acid using fused deposition modeling. All these specimens are tested in compression and their elastic modulus is obtained. Using the material parameters of the compression test specimens, the finite element analysis of the bone scaffold is performed. The obtained elastic modulus is compared with experiment indicating a good agreement. Accordingly, the proposed finite element model is able to predict the mechanical behavior of fabricated bone scaffolds accurately. In addition, the effect of post-heating of bone scaffolds on their elastic modulus is investigated. The results demonstrate that the numerically predicted elastic modulus of scaffold is closer to experimental outcomes in comparison with as-built samples. PMID:26874065

  2. Effect of addition of sugar cane biomass ash in properties of fresh state in cement slurries for oil wells; Efeito da adicao de cinza de biomassa de cana-de-acucar nas propriedades no estado fresco de pastas de cimento para pocos de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, Lornna L.A.; Santos, Herculana T.; Souza, Pablo Diego Pinheiro; Freitas, Julio Cezar Oliveira [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil); Nascimento, Julio Cesar S. [Universidade Federal da Bahia (UFBA), BA (Brazil); Amorim, Natalia M.M. [Universidade Potiguar (UNP), RN (Brazil); Martinell, Antonio E. [Mcgill University (MCGILL) (Canada); Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2012-07-01

    Recent studies have shown that ashes from biomass, in particular those generated by the alcohol industry have pozzolanic activity and can replace cement in many applications, reducing the consumption of cement and, consequently, the environmental impact caused by the production of this material. The present work evaluated the behavior of ash sugarcane biomass partially replacing Portland cement in concentrations of 10, 20 and 40% BWOC in oil well slurries. The results of rheology, thickening time and stability showed that the addition of 40% of biomass ash in oil well slurries significantly improves their properties, enabling the replacement of cement by ash. (author)

  3. Application of bone cement in the posterior approach surgical treatment for metastatic tumor of the thoracolumbar spine%胸腰椎转移瘤后路手术中骨水泥的应用

    Institute of Scientific and Technical Information of China (English)

    毛宁方; 朱晓东; 张晔; 吴云刚; 白玉树; 李明; 石志才

    2009-01-01

    目的:探讨骨水泥在胸腰椎转移瘤后路手术中的应用价值.方法:2004年3月~21208年12月,后方入路手术治疗胸腰椎转移性肿瘤患者26例,原发肿瘤:肺癌9例,乳腺癌7例,肝癌4例,前列腺癌2例,肾癌1例,来源不明3例.病灶累及单节段17例,两节段9例.23例伴不同程度的腰背部疼痛:神经功能按Frankel分级:B级6例,C级7例,D级11例,E级2例.术中采用骨水泥联合椎弓根螺钉重建脊柱稳定性,其中骨水泥填塞15个椎体,骨水泥前方重建9个椎体,骨水泥椎体成形11个椎体,10例合并骨质疏松患者同时采用骨水泥加强椎弓根钉道.结果:术中未发现骨水泥放热效应引起的神经功能受损.24例患者获得完整随访,随访时间3~42个月,平均18.2个月,23例术前有不同程度腰背疼痛者术后疼痛消失6例,缓解14例;术前伴神经功能障碍者17例(77%)获得神经功能改善.随访期间未发现骨水泥下沉、椎节塌陷及向前成角.1例骨水泥填塞术后3个月骨水泥界面出现松动,但未引起神经压迫症状.15例随访期间死亡.结论:在胸腰椎转移性肿瘤后路手术治疗中,根据患者的全身情况、预期寿命、肿瘤类型、转移椎体位置及骨密度,充分利用骨水泥独特的理化特性,进行多种不同方式的应用,可以减小手术创伤,提高生存质量.%Objective:To explore the clinic effects of the bone cement utilized in the posterior approach surgical treatment of the thoracic and lumbar spinal metastatic tumor.Method:26 patients with the thoracolumbar spinal metastatic tumors who underwent posterior approach surgical treatment from March 2004 to December 2008 were reviewed retrospectively.There were lung carcinoma in 9 cases, breast carcinoma in 7 cases, hepato-carcinoma in 4 cases,prostate carcinoma in 2 cages,kidney carcinoma in 1 case,and 3 cases with unknown origin.Tumor involved single vertebral body in 17 cases,two vertebral bodies in 9 cases.23

  4. Metaphyseal bone loss in revision knee arthroplasty.

    Science.gov (United States)

    Ponzio, Danielle Y; Austin, Matthew S

    2015-12-01

    The etiology of bone loss encountered during revision total knee arthroplasty (TKA) is often multifactorial and can include stress shielding, osteolysis, osteonecrosis, infection, mechanical loss due to a grossly loose implant, and iatrogenic loss at the time of implant resection. Selection of the reconstructive technique(s) to manage bone deficiency is determined by the location and magnitude of bone loss, ligament integrity, surgeon experience, and patient factors including the potential for additional revision, functional demand, and comorbidities. Smaller, contained defects are reliably managed with bone graft, cement augmented with screw fixation, or modular augments. Large metaphyseal defects require more extensive reconstruction such as impaction bone grafting with or without mesh augmentation, prosthetic augmentation, use of bulk structural allografts, or use of metaphyseal cones or sleeves. While each technique has advantages and disadvantages, the most optimal method for reconstruction of large metaphyseal bone defects during revision TKA is not clearly established. PMID:26362647

  5. Injectability, microstructure and release properties of sodium fusidate-loaded apatitic cement as a local drug-delivery system.

    Science.gov (United States)

    Noukrati, Hassan; Cazalbou, Sophie; Demnati, Imane; Rey, Christian; Barroug, Allal; Combes, Christèle

    2016-02-01

    The introduction of an antibiotic, sodium fusidate (SF), into the liquid phase of calcium carbonate-calcium phosphate (CaCO3-CaP) bone cement was evaluated, considering the effect of the liquid to powder ratio (L/P) on the composition and microstructure of the set cement and the injectability of the paste. In all cases, we obtained set cements composed mainly of biomimetic carbonated apatite analogous to bone mineral. With this study, we evi-denced a synergistic effect of the L/P ratio and SF presence on the injectability (i.e., the filter-pressing pheno-menon was suppressed) and the setting time of the SF-loaded cement paste compared to reference cement (without SF). In addition, the in vitro study of SF release, according to the European Pharmacopoeia recommendations, showed that, regardless of the L/P ratio, the cement allowed a sustained release of the antibiotic over 1month in sodium chloride isotonic solution at 37°C and pH7.4; this release is discussed considering the microstructure characteristics of SF-loaded cements (i.e., porosity, pore-size distribution) before and after the release test. Finally, modelling antibiotic release kinetics with several models indicated that the SF release was controlled by a diffusion mechanism. PMID:26652362

  6. Low-Temperature Additive Manufacturing of Biomimic Three-Dimensional Hydroxyapatite/Collagen Scaffolds for Bone Regeneration.

    Science.gov (United States)

    Lin, Kai-Feng; He, Shu; Song, Yue; Wang, Chun-Mei; Gao, Yi; Li, Jun-Qin; Tang, Peng; Wang, Zheng; Bi, Long; Pei, Guo-Xian

    2016-03-23

    Low-temperature additive manufacturing (AM) holds promise for fabrication of three-dimensional (3D) scaffolds containing bioactive molecules and/or drugs. Due to the strict technical limitations of current approaches, few materials are suitable for printing at low temperature. Here, a low-temperature robocasting method was employed to print biomimic 3D scaffolds for bone regeneration using a routine collagen-hydroxyapatite (CHA) composite material, which is too viscous to be printed via normal 3D printing methods at low temperature. The CHA scaffolds had excellent 3D structure and maintained most raw material properties after printing. Compared to nonprinted scaffolds, printed scaffolds promoted bone marrow stromal cell proliferation and improved osteogenic outcome in vitro. In a rabbit femoral condyle defect model, the interconnecting pores within the printed scaffolds facilitated cell penetration and mineralization before the scaffolds degraded and enhanced repair, compared to nonprinted CHA scaffolds. Additionally, the optimal printing parameters for 3D CHA scaffolds were investigated; 600-μm-diameter rods were optimal in terms of moderate mechanical strength and better repair outcome in vivo. This low-temperature robocasting method could enable a variety of bioactive molecules to be incorporated into printed CHA materials and provides a method of bioprinting biomaterials without compromising their natural properties. PMID:26930140

  7. Alternative Fuels in Cement Production

    DEFF Research Database (Denmark)

    Larsen, Morten Boberg

    The substitution of alternative for fossil fuels in cement production has increased significantly in the last decade. Of these new alternative fuels, solid state fuels presently account for the largest part, and in particular, meat and bone meal, plastics and tyre derived fuels (TDF) accounted for...... the most significant alternative fuel energy contributors in the German cement industry. Solid alternative fuels are typically high in volatile content and they may differ significantly in physical and chemical properties compared to traditional solid fossil fuels. From the process point of view......, considering a modern kiln system for cement production, the use of alternative fuels mainly influences 1) kiln process stability (may accelerate build up of blockages preventing gas and/or solids flow), 2) cement clinker quality, 3) emissions, and 4) decreased production capacity. Kiln process stability in...

  8. Osteogenesis and angiogenesis properties of dental pulp cell on novel injectable tricalcium phosphate cement by silica doped

    International Nuclear Information System (INIS)

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material in clinical. In this study, we have doped silica (Si) into β-TCP and enhanced its bioactive and osteostimulative properties. To check its effectiveness, a series of Si-doped with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of the diametral tensile strength, ions released and weight loss of cements was considered after immersion. In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on Si-doped β-TCP cements. The results showed that setting time and injectability of the Si-doped β-TCP cements were decreased as the Si content was increased. At the end of the immersion point, weight losses of 30.1%, 36.9%, 48.1%, and 55.3% were observed for the cement doping 0%, 10%, 20%, and 30% Si into β-TCP cements, respectively. In vitro cell experiments show that the Si-rich cements promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the Si-doped in the cement is more than 20%, the amount of cells and osteogenesis protein of hDPCs was stimulated by Si released from Si-doped β-TCP cements. The degradation of β-TCP and osteogenesis of Si gives a strong reason to believe that these Si-doped β-TCP cements may prove to be promising bone repair materials. - Highlights: • The higher the Si in the cement, the shorter the setting time and the higher the DTS. • Si20-doped in TCP improved cell adhesion, proliferation and differentiation. • The Si ion stimulated collagen secreted from cells. • The Si released from substrate can promote osteogenic and angiogenic

  9. Osteogenesis and angiogenesis properties of dental pulp cell on novel injectable tricalcium phosphate cement by silica doped

    Energy Technology Data Exchange (ETDEWEB)

    Su, Ying-Fang [Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan (China); Department of Stomatology, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Lin, Chi-Chang, E-mail: chichang31@gmail.com [Department of Anatomy, Chung Shan Medical University, Taichung City, Taiwan (China); Huang, Tsui-Hsien; Chou, Ming-Yung [Department of Stomatology, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Yang, Jaw-Ji, E-mail: jjyang@csmu.edu.tw [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [Department of Anatomy, Chung Shan Medical University, Taichung City, Taiwan (China)

    2014-09-01

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material in clinical. In this study, we have doped silica (Si) into β-TCP and enhanced its bioactive and osteostimulative properties. To check its effectiveness, a series of Si-doped with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of the diametral tensile strength, ions released and weight loss of cements was considered after immersion. In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on Si-doped β-TCP cements. The results showed that setting time and injectability of the Si-doped β-TCP cements were decreased as the Si content was increased. At the end of the immersion point, weight losses of 30.1%, 36.9%, 48.1%, and 55.3% were observed for the cement doping 0%, 10%, 20%, and 30% Si into β-TCP cements, respectively. In vitro cell experiments show that the Si-rich cements promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the Si-doped in the cement is more than 20%, the amount of cells and osteogenesis protein of hDPCs was stimulated by Si released from Si-doped β-TCP cements. The degradation of β-TCP and osteogenesis of Si gives a strong reason to believe that these Si-doped β-TCP cements may prove to be promising bone repair materials. - Highlights: • The higher the Si in the cement, the shorter the setting time and the higher the DTS. • Si20-doped in TCP improved cell adhesion, proliferation and differentiation. • The Si ion stimulated collagen secreted from cells. • The Si released from substrate can promote osteogenic and angiogenic.

  10. Effect of ZrO2 addition on the mechanical properties of porous TiO2 bone scaffolds

    International Nuclear Information System (INIS)

    This study aimed at the investigation of the effect of zirconium dioxide (ZrO2) addition on the mechanical properties of titanium dioxide (TiO2) bone scaffolds. The highly biocompatible TiO2 has been identified as a promising material for bone scaffolds, whereas the more bioinert ZrO2 is known for its excellent mechanical properties. Ultra-porous TiO2 scaffolds (> 89% porosity) were produced using polymer sponge replication with 0–40 wt.% of the TiO2 raw material substituted with ZrO2. Microstructure, chemical composition, and pore architectural features of the prepared ceramic foams were characterised and related to their mechanical strength. Addition of 1 wt.% of ZrO2 led to 16% increase in the mean compressive strength without significant changes in the pore architectural parameters of TiO2 scaffolds. Further ZrO2 additions resulted in reduction of compressive strength in comparison to containing no ZrO2. The appearance of zirconium titanate (ZrTiO4) phase was found to hinder the densification of the ceramic material during sintering resulting in poor intergranular connections and thus significantly reducing the compressive strength of the highly porous ceramic foam scaffolds. - Highlights: ► Open porous scaffold with porosity in the range of 89.0 to 92.8% produced. ► Adding 1 wt.% of ZrO2 led to 16% increase in strength without changing porosity. ► Further ZrO2 additions resulted in reduced compressive strength versus no ZrO2. ► Presence of zirconium titanate (ZrTiO4) phase found to hinder the densification. ► Appearance of ZrTiO4 resulted in poor intergranular connections.

  11. Performance of Cement Containing Laterite as Supplementary Cementing Material

    Directory of Open Access Journals (Sweden)

    Abbas Bukhari, Z. S.

    2013-03-01

    Full Text Available The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplemen- tary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM. The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced. Key words: Portland cement, supplementary cementing materials (SCM, laterite, compressive strength KUI – 6/2013 Received January 4, 2012 Accepted February 11, 2013

  12. Graded infusion of bone cement in percutanceous vertebroplasty for osteoporotic vertebral compression fractures%分次灌注骨水泥技术治疗骨质疏松性椎体压缩骨折疗效观察

    Institute of Scientific and Technical Information of China (English)

    耿家金; 赵平; 牛和明; 张永强; 张强; 解平锋

    2013-01-01

    Objective To explore the safety and efficacy of graded infusion of bone cement in percutanceous vertebroplasty for osteoporotic vertebral compression fractures. Methods A total of 60 patients with osteoporotic vertebral compression fractures were treated by percutanceous vertebroplasty from March 2009 to March 2011. The cases were randomly and equally assigned to a group of once infusion of bone cement (n=30)(group A) and a control group of graded infusion of bone cement (n=30) in percutanceous vertebroplasty(group B). Results The duration of mean follow-up was 18 months (range from 12 to 24 months). Compared with those before operation, the general condition and symptoms were significantly improved, and the ODI and VAS of two group were dramatically reduced in three days of postoperative and final follow-up(P 0.05). Group comparison of two group did not find significant difference (P >0.05). Compared with group A, the rate of bone cement leakage of group B was lower (P <0.05). But there were no other complications. Conclusion Percutanceous vertebroplasty, with easy performance and safely, can effectively release the pain resulted from osteoporotic vertebral compression fractures and the short-term outcome is favorable. But the long-term effects need to be further observed. Graded infusion of bone cement in percutanceous vertebroplaty can reduce the leakage rate.%目的 探讨经皮椎体成形术中采用分次灌注骨水泥技术治疗骨质疏松性椎体压缩骨折的安全性与疗效.方法 自2009年3月~2011年3月对60例骨质疏松性椎体压缩骨折采用经皮椎体成形术治疗,随机分为一次灌注骨水泥技术组(A组)30例和分次灌注骨水泥技术组(B组)30例.结果 本组获随访12~24个月,平均18个月.两组术后症状均明显改善,VAS评分及ODI评分:术后3d及末次随访与术前比较,差异均有统计学意义(P<0.01),末次随访与术后3d比较,差异无统计学意义(P>0.05),两组组间比

  13. Fabrication of HA/PLLA Composite Scaffolds for Bone Tissue Engineering Using Additive Manufacturing Technologies

    OpenAIRE

    Cruz, Fernando

    2010-01-01

    The main goal of the experimental work was to demonstrate the feasibility of producing HA/PLLA parts by selective laser sintering. The results were successful in proving that feasibility. In fact, the main results of the trials performed, have shown that: It is possible to produce bioceramic parts (HA based) by means of AMT - Additive Manufacturing Technologies, namely the Selective Laser Sintering (SLS) process, using a biocompatible/biodegradable polymer as binder; For that purpose it is ne...

  14. Biofabrication of customized bone grafts by combination of additive manufacturing and bioreactor knowhow

    International Nuclear Information System (INIS)

    This study reports on an original concept of additive manufacturing for the fabrication of tissue engineered constructs (TEC), offering the possibility of concomitantly manufacturing a customized scaffold and a bioreactor chamber to any size and shape. As a proof of concept towards the development of anatomically relevant TECs, this concept was utilized for the design and fabrication of a highly porous sheep tibia scaffold around which a bioreactor chamber of similar shape was simultaneously built. The morphology of the bioreactor/scaffold device was investigated by micro-computed tomography and scanning electron microscopy confirming the porous architecture of the sheep tibiae as opposed to the non-porous nature of the bioreactor chamber. Additionally, this study demonstrates that both the shape, as well as the inner architecture of the device can significantly impact the perfusion of fluid within the scaffold architecture. Indeed, fluid flow modelling revealed that this was of significant importance for controlling the nutrition flow pattern within the scaffold and the bioreactor chamber, avoiding the formation of stagnant flow regions detrimental for in vitro tissue development. The bioreactor/scaffold device was dynamically seeded with human primary osteoblasts and cultured under bi-directional perfusion for two and six weeks. Primary human osteoblasts were observed homogenously distributed throughout the scaffold, and were viable for the six week culture period. This work demonstrates a novel application for additive manufacturing in the development of scaffolds and bioreactors. Given the intrinsic flexibility of the additive manufacturing technology platform developed, more complex culture systems can be fabricated which would contribute to the advances in customized and patient-specific tissue engineering strategies for a wide range of applications. (paper)

  15. Correlation of pull-out strength of cement-augmented pedicle screws with CT-volumetric measurement of cement.

    OpenAIRE

    Fölsch, Christian; Goost, Hans; Figiel, Jens; Paletta, Jürgen R. J.; Schultz, Wolfgang; Lakemeier, Stefan

    2012-01-01

    BACKGROUND: Cement augmentation of pedicle screws increases fixation strength in an osteoporotic spine. This study was designed to determine the cement distribution and the correlation between the pull-out strength of the augmented screw and the cement volume within polyurethane (PU) foam. METHODS: Twenty-eight cannulated pedicle screws (6×45 mm) (Peter Brehm, Erlangen, Germany) with four holes at the distal end of the screw were augmented with the acrylic Stabilit ER Bone Cement Vertebr...

  16. The influence of cement mantle thickness and stem geometry on fatigue damage in two different cemented hip femoral prostheses.

    Science.gov (United States)

    Ramos, A; Simões, J A

    2009-11-13

    Experimental models can be used for pre-clinical testing of cemented and other type of hip replacements. Total hip replacement (THR) failure scenarios include, among others, cement damage accumulation and the assessment of accurate stress and strain magnitudes at the cement mantle interfaces (stem-cement and cement-bone) can be used to predict mechanical failure. The aseptic loosening scenario in cemented hip replacements is currently not fully understood, and methods of evaluating medical devices must be developed to improve clinical performance. Different results and conclusions concerning the cement micro-cracking mechanism have been reported. The aim of this study was to verify the in vitro behavior of two cemented femoral stems with respect to fatigue crack formation. Fatigue crack damage was assessed at the medial, lateral, anterior and posterior sides of the Lubinus SPII and Charnley stems. All stems were loaded and tested in stair climbing fatigue loading during one million cycles at 2 Hz. After the experiments each implanted synthetic femur was sectioned and analyzed. We observed more damage (cracks per area) for the Lubinus SPII stem, mainly on the proximal part of the cement mantle. The micro-cracking formation initiated in the stem-cement interface and grew towards the direction of cortical bone of the femur. Overall, the cement-bone interface seems to be crucial for the success of the hip replacement. The Charnley stem provoked more damage on the cement-bone interface. A failure index (maximum length of crack/maximum thickness of cement) considered was higher for the cement-stem interface of the Lubinus SPII stem. For a cement mantle thickness higher than 5 mm, cracking initiated at the cement-bone interface and depended on the opening canal process (reaming procedure and instrumentation). The analysis also showed that fatigue-induced damage on the cement mantle, increasing proximally, and depended on the axial position of the stem. The cement

  17. Biomechanical effects of kyphoplasty-assisted versus traditional bone cement augmentation on the loosened sacral screws%后凸成形和传统钉道骨水泥强化对骶骨钉松动的生物力学作用

    Institute of Scientific and Technical Information of China (English)

    周冬长; 王丽冰; 曾丽雯; 黄阳亮; 于滨生

    2011-01-01

    BACKGROUND: Kyphoplasty-assisted bone cement augmentation can be used in lumbar pedicle screw fixation of osteoporotic patients.OBJECTIVE: To assess the fixation strengths of loosened sacral screws augmented with kyphoplasty-assisted and traditional bone cement techniques.METHODS: Fresh sacra were harvested from nine osteoporotic cadavers. After testing bilaterally placed unicortical and bicortical pedicle screws, two unicortical pedicle screws with the traditional and kyphoplasty-assisted cement augmentations were established on the same sacrum. Following 2000 cyclic compression loading to screw head on a MTS machine, their maximum pull-out forces were recorded and compared. RESULTS AND CONCLUSION: The bone mineral densities of nine specimens were ranged from 0.61 to 0.77 g/cm2 (0.71 g/cm2 in average). The mean maximum pull-out forces of unicortical and bicortical screws, and traditional and kyphoplasty-assisted cement screws were 203, 325, 437, and 565 N, respectively. The pull-out force was significantly higher in bicortical screw compared with unicortical (P < 0.05); however, these two fixations exhibited markedly lower pull-out strength compared with two cement augmentation techniques (P < 0.05). The pull-out strength was significantly higher in kyphoplasty-assisted cement augmentation group compared with traditional bone cement technique (P < 0.05). In addition, a significant positive correlation was exhibited between bone mineral density and pull-out force for the four fixations (P < 0.05). Results demonstrated that traditional and kyphoplasty-assisted cement augmentations can serve as the salvage technique for loosening sacral screw. However, kyphoplasty-assisted augmentation can provide higher stability.%背景:后凸成形骨水泥强化可应用于骨质疏松患者的腰椎椎弓根钉固定.目的:评价松动的骶骨钉经后凸成形和传统钉道骨水泥强化后的固定强度.方法:纳入9具骨质疏松症患者的新鲜尸体标本.在同

  18. 注入骨水泥治疗胸腰椎骨质疏松性骨折:成熟技术中的常见问题%Bone cement injection for the treatment of thoracolumbar osteoporotic fractures:Common problems in the mature technology

    Institute of Scientific and Technical Information of China (English)

    韩卫东; 黄爱军; 陈丽萍

    2013-01-01

      背景:注入骨水泥是胸腰椎骨质疏松性骨折常用的固定方法之一。目的:评估注入骨水泥内固定胸腰椎骨质疏松性骨折的生物力学性能以及固定效果。方法:选取骨质疏松胸腰椎标本,测定骨密度以及最大压力载荷、位移、刚度等力学性能指标,建立骨折模型,注入骨水泥固定后,再次测定最大压力载荷、位移、刚度指标,比较注入骨水泥固定前后生物性能的变化,同时与椎弓根螺钉固定胸腰椎骨质疏松性骨折的生物学性能进行比较。对注入骨水泥固定胸腰椎骨质疏松性骨折的患者进行随访观察,通过评估患者缓解疼痛程度、胸腰椎体高度恢复程度以及骨水泥注入量和骨水泥外渗等情况,明确注入骨水泥固定治疗的效果。结果与结论:生物力学实验测定注入骨水泥固定胸腰椎骨质疏松性骨折后的最大载荷为2285 N,比骨折前承受的最大载荷1954 N强度增加了近16.9%,注入骨水泥固定胸腰椎骨质疏松性骨折后的刚度为427 N,比骨折前刚度349 N增加了近22.1%,显示出良好的生物性能。对应用注入骨水泥固定胸腰椎骨质疏松性骨折的患者以及应用闭合复位注入骨水泥固定胸腰椎骨质疏松性骨折的患者进行随访观察,结果发现2种方法均可以使患者的疼痛得到明显的缓解,而闭合复位注入骨水泥固定胸腰椎骨质疏松性骨折时骨水泥注入量、局部后凸角以及椎体高度恢复情况均更好,表明闭合复位辅助下注入骨水泥固定是胸腰椎骨质疏松性骨折安全有效的治疗方法。%  BACKGROUND: Bone cement injection is one of the commonly used methods for the treatment of thoracolumbar osteoporotic fractures. OBJECTIVE: To evaluate biomechanical properties and fixed effects of bone cement injection for the treatment of thoracolumbar osteoporotic fractures. METHODS: The specimens of

  19. geneX®骨水泥强化椎弓根螺钉体内的实验研究%The experiment study of geneX® bone cement augmentation of pedicle screw in animal model

    Institute of Scientific and Technical Information of China (English)

    张树芳; 江建明; 陈荣春; 朱青安; 黄志平

    2015-01-01

    目的:通过动物实验,评估新型带负电荷硫酸钙/β-磷酸三钙复合骨水泥(geneX®)用于强化体内椎弓根螺钉的生物力学性质变化及可行性。方法选取6只健康山羊腰椎L1~5双侧共30个椎弓根随机分为3组:geneX®组,聚甲基丙烯酸甲酯骨水泥(Polymethylmethacrylate,PMMA)组,空白对照组,每组10个椎弓根。术后3个月处死动物取材行Mirco-CT检查、组织学检查及生物力学实验。结果轴向拔出力实验:geneX®组(803±155) N, PMMA组为(994±122) N,两者差异无统计学意义(P>0.05)。两组均明显高于对照组的(524±118) N,差异具有统计学意义(P<0.05)。组织学观察及Mirco-CT显示geneX®组中螺钉周围骨水泥已经完全降解、吸收,骨小梁排列致密,成熟骨小梁附近可见大量新生骨组织,明显优于对照组及PMMA组。结论 geneX®骨水泥可有效强化椎弓根螺钉内固定的强度,其强化作用随时间推移而增强,对防止骨质疏松症患者内固定的拔出发生率有重要意义。%Objective To evaluate the long-term in vivo biomechanical effects of a newly developed biphasic calcium composite bone cement (geneX®)with a negative surface charge augmentation of pedicle screw. Methods Bilateral pedicles of lumbar vertebrae (L1~5) of 6 female sheep were fi xed with pedicle screws. One pedicle of each vertebral body was treated with a screw augmented with either geneX®(geneX® group) or PMMA (PMMA group) and the contralateral pedicle was treated with a screw without any augmentation (control group). Three months later, the sheep were killed and biomechanical tests, micro-CT analysis and histological observation were conducted on the isolated specimen vertebrae. Results Both the axial and vertical stabilities of the pedicle screws in geneX® group were significantly enhanced compared with those in the control group (P<0.05). Micro-CT reconstruction and analysis showed that there were more bone

  20. Amino acid containing glass-ionomer cement for orthopedic applications

    Science.gov (United States)

    Wu, Wei

    Amino acid containing glass-ionomer cements were synthesized, formulated, and evaluated for orthopedic application. The formulation of different amino acid containing glass-ionomer bone cements was optimized, and conventional and resin-modified glass-ionomer bone cements were compared. Properties of interest included handling characteristics, physical and chemical properties, and mechanical strength of the bone cement. The study was based on the synthesis of different vinyl containing amino acids, different polyelectrolytes containing these amino acid residues, and different resin-modified polyelectrolytes, as well as formulation and evaluation of conventional and resin-modified glass-ionomer bone cements using these polyelectrolytes. Systematic preparation of polyelectrolytes and formulation of glass-ionomer bone cements were essential features of this work, since we anticipated that the mechanical properties of the glass-ionomer bone cements could be strongly affected by the nature of the polyelectrolytes and formulation. Mechanical properties were evaluated in a screw driven mechanical testing machine, and structure-property relationships were determined by scanning electron microscopic (SEM) observation of the fracture surface of the specimens. How the structure of polyelectrolytes, such as different amino acid residues, molecular weight, different modifying resin, and formulation of glass-ionomer bone cement, affected the mechanical properties was also studied.

  1. Inlfuence of Additives on Shrinkage and Early-age Crack Resistance of Slag Cement Concrete%外加剂对矿渣水泥混凝土收缩与早期抗裂的影响

    Institute of Scientific and Technical Information of China (English)

    韩静云; 宋旭艳; 郜志海

    2016-01-01

    选用木钠减水剂、UEA-H膨胀剂、早强剂、柠檬酸缓凝剂以常用掺量外掺入矿粉水泥中,检测其化学收缩和干缩性能,同时将各掺量的外加剂分别引入到矿渣水泥混凝土中,检测其抗压强度以及早期抗裂性能,结果表明:木钠减水剂增加矿渣水泥的早期化学收缩,也增大矿渣水泥胶砂的干缩值;UEA-H膨胀剂增加矿渣水泥的化学收缩,并能降低矿渣水泥胶砂的干缩;早强剂则在早期就大幅度增加矿渣水泥的化学收缩,对胶砂体系干缩性能影响与基准矿渣水泥体系相当;柠檬酸缓凝剂能降低矿渣水泥的化学收缩值,但会提高胶砂体系的干缩值。木钠减水剂、UEA-H膨胀剂和早强剂都能提高矿渣水泥混凝土的早期抗裂性能,其中早强剂在所选用的几种外加剂中效果最好,而缓凝剂对矿渣水泥混凝土早期抗裂性能具有不利影响。%Sodium ligninsulfonate water reducer, UEA-H expansive agent, early strength agent and citric acid retarder could be introduced into slag cement, and then chemical shrinkage and dry shrinkage of system may be tested. After slag concrete with various additives respectively can be prepared, its compressive strength and early crack resistance may be determined. The results can show that: sodium ligninsulfonate water reducer can increase early chemical shrinkage and dry shrinkage of slag cement. UEA-H expansive agent can increase chemical shrinkage and reduce dry shrinkage of slag cement. Early strength agent can substantially increase early chemical shrinkage of slag cement. Inlfuence of early strength agent on dry shrinkage of slag cement may be similar to fundamental slag cement. Citric acid retarder can reduce chemical shrinkage of slag cement, but may improve dry shrinkage of cement system. Sodium ligninsulfonate water reducer, UEA-H expansive agent, early strength agent could improve early cracking resistance of slag concrete

  2. Concrete = aggregate, cement, water?

    International Nuclear Information System (INIS)

    Concrete for the Temelin nuclear power plant is produced to about 70 different formulae. For quality production, homogeneous properties of aggregates, accurate proportioning devices, technological discipline and systematic inspections and tests should be assured. The results are reported of measuring compression strength after 28 days for different concrete samples. The results of such tests allow reducing the proportion of cement, which brings about considerable savings. Reduction in cement quantities can also be achieved by adding ash to the concrete mixes. Ligoplast, a plasticizer addition is used for improving workability. (M.D). 8 figs

  3. Composite cements containing natural pozzolan and granulated blast furnace slag

    OpenAIRE

    Irassar, E. F.; Rahhal, V.F.; Donza, H. A.; Menéndez, G.; Bonavetti, V. L.

    2006-01-01

    For reasons of market demand and Portland cement production,the manufacture of cements with two or more separately ground additions to produce customized cements is becoming common practice.When pozzolan or slag content in this type of cements is high, however, the initial strength of the resulting product may be adversely impacted. This problem can be minimized by activating one or both of the replacement materials. The present study analyzes the effect of Portland cement additions such as p...

  4. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  5. 不同量骨水泥强化新型空心椎弓根螺钉的体外生物力学研究%Influence of the volume of bone cement on the reinforcement of a novel canulated pedicle screw: a biomechanical study in vitro

    Institute of Scientific and Technical Information of China (English)

    刘瑶瑶; 代飞; 孙东; 罗飞; 张泽华; 许建中

    2012-01-01

    Objective To evaluate the bone cement distribution and biomechanical stability of self-designed bone cement injectable canulated pedicle screw (CICPS). Methods CICPS, DTPSTM and solid pedicle screws were implanted into osteoporotic bone models (density: 0. 16 g/cm3, n = 7) according to the clinical standard procedure. Four different volumes of bone cement (1,2,3 and 5 ml) were used to reinforce CICPS and DTPSTM , respectively, and the solid pedicle screws were used as control. X-ray and CT were applied to observe the bone cement distribution in different groups. Maximum axial pullout strength test was used to analyze the relationship between the bone cement volume and maximum axial pullout strength, and the biomechanical stabilities of CICPS, DTPS and solid pedicle screws were compared. Results X-ray showed that there was no bone cement rear leakage in all screws. Three-dimensional reconstruction of X-ray and CT showed bone cement well and widely distributed through the three side holes of the CICPS in bone models. Bone cement flowed out mainly through the proximal side hole of the DTPSTM But rarely through the distal side hole. The maximum axial pullout strength of each group was as follows: solid pedicle screws; (28.5 ±4.0) N; CICPS: 1 ml (140.3 ±15.9) N, 2 ml (197. 1 ±9.8) N, 3 ml (215.4 ±10.7) N and 5 ml (237.0 ±23.6) N; and DTPSTM: 1 ml (114. 3 ± 17.7) N, 2 ml (180.5 ±13.6) N, 3 ml (207.2 ±30.0) N and 5 ml (291.3 ± 25. 1) N. The maximum axial pullout strength of the CICPS and DTPSTM after reinforced by bone cement was significantly greater than that of the control group, and the strength increased along with the increase of bone cement volume. When the volume of bone cement was 1, 2 and 3 ml, the biomechanical stability of the CICPS was higher than that of the DTPSTM ( P <0. 05 ). When the volume of bone cement was 5 ml, the biomechanical stability of the DTPSTM Was higher than that of the CICPS (P <0. 05). Conclusion It is effective to enhance the

  6. Time reduction in well construction with the addition of glass microspheres and thixotropic agents in cement slurries in zonal isolation at Solimoes Basin; Reducao do tempo de construcao de pocos de petroelo na Bacia do Solimoes atraves da utilizacao de microsferas de vidro e agentes tixotropicos nas fases de cimentacao

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Cledeilson R.L.; Duque, Luis H.; Steffan, Rodolfo H.P.; Guimaraes, Zacarias [Baker Hyghes, Houston, TX (United States); Corregio, Fabio; Augusto, Marcelo; Mendes, Sandro C. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    One of the problems faced by the oil industry during the well construction is the damage effect of the hydrostatic head of cement slurries on unconsolidated reservoirs, trending to a necessity of lightweight cementing slurries with high resistance for zonal isolation. This paper presents experiences with lightweight cementing slurries obtained by the addition of glass microspheres and thixotropic agents in oil and gas wells located at Solimoes Basin - Amazon Basin, Brazil, which led to 100% time reduction on well construction when compared with the standard cementing procedures, besides the benefit of no reservoir damage. It also includes lab tests, cement slurry designs, case histories and results that allow a complete evaluation of the technique that can be applied in other similar environments. (author)

  7. Murine osteoblastic and osteoclastic differentiation on strontium releasing hydroxyapatite forming cements.

    Science.gov (United States)

    Singh, Satish S; Roy, Abhijit; Lee, Boeun; Parekh, Shrey; Kumta, Prashant N

    2016-06-01

    Ionic substitutions in hydroxyapatite (HA) scaffolds and self-setting cements containing Sr(2+) ions incorporated are particularly of interest in bone regeneration. To date, the approach widely used to incorporate Sr(2+) ions into HA cements has been the addition of Sr(2+) containing salts, such as SrCO3, SrCl2∙6H2O, or SrHPO4. However, this approach is dependent upon the relative solubility of Sr(2+) containing salts with respect to calcium phosphate (CaP) precursors. Therefore, in the current study Sr(2+) substituted dicalcium phosphate dihydrate (DCPD) was first synthesized and directly reacted with tetracalcium phosphate (TTCP) to form Sr(2+) substituted HA forming cements. Rietveld refinement indicated that after one week of aging in phosphate buffered saline, cements prepared with and without Sr(2+) were composed of 75% HA and 25% unreacted TTCP by weight. Cements prepared with 10% Sr(2+) DCPD exhibited increased compressive strengths in comparison to unsubstituted cements. Increased MC3T3-E1 proliferation and differentiation were also observed on the cements prepared with increasing Sr(2+) content. It was concluded that both the scaffold microstructure and Sr(2+) ion release supported osteogenic differentiation. With respect to osteoclastic differentiation, no statistically significant differences in TRAP activity or cell morphology were observed. This suggests that the amount of Sr(2+) released may have been too low to influence osteoclast formation in comparison to unsubstituted cements. The results obtained herein demonstrate that the use of Sr(2+) substituted DCPD precursors rather than individually separate Sr(2+) containing salts may be a useful approach to prepare Sr(2+) containing HA cements. PMID:27040237

  8. A New Type of Biphasic Calcium Phosphate Cement as a Gentamicin Carrier for Osteomyelitis

    Directory of Open Access Journals (Sweden)

    Wen-Yu Su

    2013-01-01

    Full Text Available Osteomyelitis therapy is a long-term and inconvenient procedure for a patient. Antibiotic-loaded bone cements are both a complementary and alternative treatment option to intravenous antibiotic therapy for the treatment of osteomyelitis. In the current study, the biphasic calcium phosphate cement (CPC, called α-TCP/HAP (α-tricalcium phosphate/hydroxyapatite biphasic cement, was prepared as an antibiotics carrier for osteomyelitis. The developed biphasic cement with a microstructure of α-TCP surrounding the HAP has a fast setting time which will fulfill the clinical demand. The X-ray diffraction and Fourier transform infrared spectrometry analyses showed the final phase to be HAP, the basic bone mineral, after setting for a period of time. Scanning electron microscopy revealed a porous structure with particle sizes of a few micrometers. The addition of gentamicin in α-TCP/HAP would delay the transition of α-TCP but would not change the final-phase HAP. The gentamicin-loaded α-TCP/HAP supplies high doses of the antibiotic during the initial 24 hours when they are soaked in phosphate buffer solution (PBS. Thereafter, a slower drug release is produced, supplying minimum inhibitory concentration until the end of the experiment (30 days. Studies of growth inhibition of Staphylococcus aureus and Pseudomonas aeruginosa in culture indicated that gentamicin released after 30 days from α-TCP/HAP biphasic cement retained antibacterial activity.

  9. Preparation and evaluation of high temperature cement slurry loss reduction additive DRF-120L%高温水泥浆降失水剂DRF-120L的制备及评价

    Institute of Scientific and Technical Information of China (English)

    于永金; 刘硕琼; 刘丽雯; 靳建洲; 袁进平; 齐奉忠

    2011-01-01

    The cement fluid loss reduction additives used in China generally have the deficiency of weak salinity tolerance and poor thermal stability. To solve this problem, considering molecular structure, excellent performance monomers were selected, and then the salt tolerant and thermostable fluid loss reduction additive DRF-120L was prepared according to free radical polymerization in aqueous solution. DRF-120L is a type of copolymer and its main chain contains sulfonic group and dicarboxyl groups, which improves the adsorption capacity to cement particle, so the capacity of controlling fluid loss was improved. The initiator amount, reaction temperature, monomer mass fraction were investigate, and the optimum polymerization conditions was determined. Finally DRF-120L was synthesized with temperature resistance of up to 200 °C .API fluid loss both in fresh water cement slurry and saline water cement slurry can be controlled under 100 ml under high temperature. DRF-120L has little effect on development ofcement strength under high temperature. Both conventional density cement slurry and high density cement slurry mixed mainly with DRF-120L have good comprehensive properties. Therefore, DRF-120L can satisfy the requirement of high temperature and deep well cementing.%目前国内使用的合成聚合物类降失水剂普遍存在抗高温、抗盐能力差的问题,为解决这一问题,从分子结构入手,优选出性能优异的聚合单体,采用水溶液自由基共聚合法制备了抗高温、抗盐降失水剂DRF-120L.DRF-120L分子主链上引入了磺酸基及双羧基等多种官能团,提高了降失水剂对水泥粒子的吸附能力,从而提高了降失水剂在高温下控制水泥浆失水的能力.分别考察了引发剂加量、反应温度及单体浓度等因素对降失水剂性能的影响,确定了聚合反应的最佳合成条件,制备出了抗温达到200℃的降失水剂DRF- 120L.DRF-120L在高温下能将淡水水泥浆及含盐

  10. 负压吸引引流技术联合抗生素骨水泥链珠治疗慢性骨髓炎%Continuous Vacuum Sealing Drainage Combined with Antibiotic Bone Cement Renju for Chronic Osteomyeliti

    Institute of Scientific and Technical Information of China (English)

    李宗原; 王军; 王陶; 石波; 杨衡; 张定伟

    2014-01-01

    Objective To study the effect of combination of continuous vacuum sealing drainage (VSD) combined with antibiotic bone cement renju for chronic osteomyeliti. Methods From April 2012 to April 2013, Fifty-three patients of chronic osteomyeliti of the author’s hospital were randomly divided into two groups. The treatment group (21 cases) was treated with VSD with antibiotic bone cement renju. The control group (32 cases) was treated with antibiotic bone cement renju. The evaluation in-dex were compared, such as length of stay, average operation time ,dressing change frequency, the number of operations, healing time, recurrence rate, et al. Results There were no difference in length of stay, average operation time, the number of opera-tions. The healing time, dressing change frequency of the treatment group were significantly less than the control group (P < 0. 05). Conclusions In the treatment of chronic osteomyelitis, VSD combined with antibiotic bone cement renju had advantages of promoting wound growth, reducing the number of change of dressing and the time of rehabilitation.%目的:探讨负压吸引引流技术(VSD)联合抗生素骨水泥链珠治疗慢性骨髓炎的临床疗效。方法选取笔者所在医院自2012年4月至2013年4月收治的53例慢性骨髓炎患者,随机分为观察组(VSD +抗生素链珠组)21例和对照组(抗生素链珠组)32例,观察组采用持续负压封闭引流联合抗生素骨水泥链珠填充,结合全身抗生素应用治疗。对照组经骨窗安放抗生素骨水泥链珠。比较两组患者住院天数,平均每次手术时间,换药次数、手术次数,创面愈合时间,复发率等指标。结果在住院天数、手术平均时间、手术次数方面两组患者无统计学差异,在换药次数、创面愈合时间方面观察组少于对照组(P <0.01)。结论 VSD 联合抗生素骨水泥链珠治疗慢性骨髓炎效果理想,可减少换药次数、缩短创面愈合时间。

  11. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    OpenAIRE

    Konstantin Sobolev

    2003-01-01

    The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecologi...

  12. Supporting screws combined with bone cement filling for reconstructing tibial bone defect in knee arthroplasty%支撑螺钉结合骨水泥填充重建膝关节置换术中胫骨平台骨缺损

    Institute of Scientific and Technical Information of China (English)

    黄海; 张喜才

    2014-01-01

    Objective To observe the clinical effect of supporting screws combined with bone cement filling on reconstructing tibial bone defect in knee arthroplasty.Methods Thirty-one patients (47 lateral tibial plateau structural bone defect) underwent total knee replacement.After conventional tibial osteotomy,2 or 3 pieces of supporting screws were screwed according to bone defect area,and bone cement was pressurely filled,and then the tibial prosthesis was installed.The knee rehabilitation training was strengthened and the effect was regular followed up after the operation.Results Thirty-one patients were followed up for 1-5 years,average 2.8 years.The pain of the knee completely disappeared after operation,and the stability and function of the knee were good.The KSS knee score were 87 to 95 points,an average of 92.4 points,which were significantly improved after operation (t =6.41,P < 0.01).In the last follow-up through X-ray examination,there were no prosthesis loosening or signs of infection,no bone cement filling zone interface lucency or supporting screw loosening,displacement or other complications.Conclusions Supporting screws combined with bone cement filling technique can effectively resolve the tibial knee replacement of large bone defects,and the short-term curative effect is satisfactory.So it is one of the ideal methods for senile patients.%目的 观察支撑螺钉结合骨水泥填充重建膝关节置换术中胫骨平台骨缺损的临床疗效.方法 对31例47侧重度胫骨平台结构性骨缺损患者行全膝关节置换术,常规胫骨平台截骨,截骨后根据骨缺损面积,拧入2~3枚支撑螺钉,加压填充骨水泥,安置胫骨骨水泥假体.术后加强膝关节功能康复训练并定期随访疗效.结果 31例患者术后随访1~5年,平均2.8年,术后疼痛完全消失,膝关节稳定性及功能均良好.膝关节KSS评分87~95分,平均92.4分,较术前显著改善(t=6.41,P<0.01).术后末次随访复查X线片未见

  13. Development of Clinical Cement of Nanoapatite and Polyamide Composite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new type of inorganicorganic biomimetic bone cement consisting of nanohydroxyapatite and polyamide 66 composite was investigated. This cement can be handled as paste and easily shaped into any contour. Nanoapatite and polyamide composite cement has a reasonable setting time, excellent washout resistance, high mechanical strength and bioactivity, and it is easily handled and shaped, which can be developed as a clinical cement. It can be predicted that nanoapatite/polymer composite cement would be a new trend of biomedical material, showing a promising prospect.

  14. Microstructure of Steel Fiber Reinforced Polymer-cement-based Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Mercury intrusion porosimetry was used to measure the pore structure of steel fiber reinforced polymer-cement-based composite.The results indicate that the large pore volume decreases by 57.8%-51.2% and by 87.1%-88% with the addition of steel fibers and polymers respectively.When both steel fibers and polymers are simultaneously added,the large pore volume decreases by 88.3%-90.1%.As a surface active material,polymer has a favorable water-reduced and forming-film effect,which is contributed to the decrease of the thickness of water film and the improvement of the conglutination between the fibers and the matrix.Polymers could form a microstructure network.This network structure and the bone structure of cement hydration products penetrate each other and thus the interpenetrating network with sticky aggregate and steel fiber inside forms.

  15. 腰椎内固定中两种椎弓根钉加强技术与骨水泥的应用%Two strengthening pedicle screw techniques and bone cement in lumbar internal fixation

    Institute of Scientific and Technical Information of China (English)

    江泽华; 朱如森; 袁建军; 邵高升; 张学利

    2013-01-01

    BACKGROUND:Screw loosening and shedding may occur after osteoporosis associated with lumbar degenerative disease treated with pedicle screw fixation. Application of pedicle screw enhanced with cured materials can improve the therapeutic effect. OBJECTIVE:To compare the clinical effect of pedicle screws enhanced with poly(methyl methacrylate) and injectable calcium sulfate cement in the lumbar internal fixation of osteoporosis. METHODS:Sixty-one patients diagnosed with osteoporosis combined with lumbar spondylolisthesis, lumbar spinal instability, and severe lumbar spinal stenosis were col ected. Al patients were divided into two groups according to the treatment method:poly(methyl methacrylate) bone cement enhanced pedicle screw group and calcium sulfate bone cement enhanced pedicle screw group. RESULTS AND CONCLUSION:There were no significant differences in the operation time, blood loss, preoperative and postoperative visual analog scale score, Japanese Orthopedic Association scores and the Japanese Orthopedic Association score improvement rate between two groups (P>0.05). The results showed that two patients had bone cement leakage in poly(methyl methacrylate) group which had no neurological symptoms caused by new symptoms during fol ow-up period. The bone mineral density was not improved gradual y in poly(methyl methacrylate) group with fol ow-up time prolonging;however, in calcium sulfate group, the bone mineral density was increased significantly after treatment, and the change of bone mineral density was linearly related with Japanese Orthopaedic Association score improvement rate in calcium sulfate group. No screw loosening, pul ing out or neurological dysfunction occurred in both groups. The results indicate that like poly(methyl methacrylate), balcium sulfate bone cement can increase the stability of pedicle screws.%背景:骨质疏松伴腰椎退行性病变行椎弓根钉固定骨质疏松的椎体后可能会出现螺钉的松动、脱落,使用

  16. A Blended Cement Containing Blast Furnace Slag and Phosphorous Slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Blended cement containing blast furnace slag(BFS) and phosphorous slag(PS) is a new kind of cement.The total content of blended materials could increase if two additives were used. Using the same admixtures, the properties of the blended cement with 70% additives could reach the standard of 525-grade slag cement according to GB.The strength of cement with 80% additives could reach the standard of 425-grade slag cement.The tests of strength, pore structure,hydration products,inhibiting alkali-aggregate reaction, resistance to sulfate corrosion of BFS-PSC were performed.

  17. Less harmful acidic degradation of poly(lactic-co-glycolic acid) bone tissue engineering scaffolds through titania nanoparticle addition

    OpenAIRE

    Liu, Huinan; Slamovich, Elliott B; Webster, Thomas J

    2006-01-01

    In the last 10 years, biodegradable aliphatic polyesters, such as poly(lactic-co-glycolic acid) (PLGA), have attracted increasing attention for their use as scaffold materials in bone tissue engineering because their degradation products can be removed by natural metabolic pathways. However, one main concern with the use of these specific polymers is that their degradation products reduce local pH, which in turn induces an inflammatory reaction and damages bone cell health at the implant site...

  18. Preparation and characterization of nano-hydroxyapatite/carboxymethychitosan-sodium alginate bone cement composite material%纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥的性能

    Institute of Scientific and Technical Information of China (English)

    肖海军; 薛锋; 何志敏; 金粉勤; 沈玉春

    2011-01-01

    BACKGROUND: Bone adhesives have more or few shortcomings themselves at present.OBJECTIVE: To develop a new kind of bioactive bone cement that can be used as fracture adhesion.METHODS: Nano-hydroxyapatite/carboxymethychitosan-sodium alginate bone cement composite material as solid phase wasprepared through a co-precipitation method, and citric acid derivant as liquid phase was prepared for solution. By optimizedexperimentation in situ setting, the appropriate prescription of the cement was screened out according to the test of setting time,compressive strength, tensile strength, anti -washout ability, and microstructure and crystal construction of the cement werecharacterized by using Fourier transform infrared spectroscopy and scanning electron microscope.RESULTS AND CONCLUSION: When the mass ratio of nano-hydroxyapatite/carboxymethychitosan-sodium alginate was 65/35(among carboxymethychitosan/sodium alginate 4∶1) and liquid/solid was 1.0∶ 0.5 (g: mL), the prepared cement was paste-likewith good plasti city and anti -washout ability; the setting time was 12 to 18 minutes; the compressive strength was (4.5±2.1) MPa;the tensile strength of the femoral head of pigs had no difference at 25 ℃ and 37 ℃ in vitro (P > 0.05); the tensile strength at2 hours was 94% similar as that at 24 hours after the setting; the range of the porous structure was 100-300 μm;Nano-hydroxyapatite was well-distributed in the porous structure. The nano-hydroxyapatite/carboxymethychitosan-sodiumalginate bone cement has good biological activity, appropriate compressive strength, and preferable adhesive strength.%背景:目前普遍使用的黏合剂对粉碎骨折块进行黏合复位或多或少都存在一些缺陷.目的:研制具有黏接骨骼作用的生物活性骨水泥.方法:应用共沉淀法制备纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合材料作为骨水泥的固相粉体,将柠檬酸衍生物配制成溶液作为液相.通过优化实验,从骨水泥

  19. Gelatin-Modified Bone Substitute with Bioactive Molecules Enhance Cellular Interactions and Bone Regeneration.

    Science.gov (United States)

    Teotia, Arun Kumar; Gupta, Ankur; Raina, Deepak Bushan; Lidgren, Lars; Kumar, Ashok

    2016-05-01

    In this work, we have synthesized injectable bone cement incorporated with gelatin to enhance cellular interaction. Human osteosarcoma Saos-2 cells derived bone morphogenetic proteins (BMP's) and a bisphosphonate (zoledronic acid (0.2 mM)) were also incorporated to cement. In vitro studies conducted using Saos-2 demonstrated enhanced cell proliferation on gelatin (0.2%w/v) cement. The differentiation of C2C12 mouse myoblast cells into bone forming cells showed 6-fold increase in ALP levels on gelatin cement. Polymerase chain reaction (PCR) for bone biomarkers showed osteoinductive potential of gelatin cement. We investigated efficacy for local delivery of these bioactive molecules in enhancing bone substitution qualities of bone cements by implanting in 3.5 mm critical size defect in tibial metaphysis of wistar rats. The rats were sacrificed after 12 weeks and 16 weeks post implantation. X-ray, micro-CT, histology, and histomorphometry analysis were performed to check bone healing. The cement materials slowly resorbed from the defect site leaving HAP creating porous matrix providing surface for bone formation. The materials showed high biocompatibility and initial bridging was observed in all the animals but maximum bone formation was observed in animals implanted with cement incorporated with zoledronic acid followed by cement with BMP's compared to other groups. PMID:27077816

  20. The bactericidal and biocompatible characteristics of reinforced calcium phosphate cements

    International Nuclear Information System (INIS)

    Infection remains a serious medical problem in orthopaedic surgery. Antibiotic administration can be available either systemically via the blood stream or locally, directly into the infected bone. One of the main limitations of antibiotic administration is the development of multi-antibiotic-resistant bacterial strains. In this study, we developed bactericidal calcium phosphate cements (CPC) by incorporation of different molecular weight chitosan and hydroxypropyltrimethyl ammonium chloride chitosan (HACC). Two standard strains, S. epidermidis (ATCC35984) and S. aureus (ATCC25923), and one clinical isolate, methicillin-resistant S. epidermidis (MRSE), were selected to evaluate the antibacterial activity of these bone cements. Our data showed that the CPC loaded with low molecular weight chitosan and HACC significantly inhibited the bacterial adhesion and biofilm formation. In addition, HACC-containing CPC has no cytotoxic effects on both mouse pluripotent C3H10T1/2cell line and a murine L929 fibroblast cell line. We propose that HACC-containing CPC represents a promising polymer-based bactericidal bone scaffold in controlling orthopaedic surgery-related infection. (paper)

  1. Bone response and mechanical strength of rabbit femoral defects filled with injectable CaP cements containing TGF-beta 1 loaded gelatin microparticles.

    NARCIS (Netherlands)

    Link, D.P.; Dolder, J. van den; Beucken, J.J.J.P van den; Wolke, J.G.C.; Mikos, A.G.; Jansen, J.A.

    2008-01-01

    This study focused at the potential of transforming growth factor beta 1 (TGF-beta 1) loaded gelatin microparticles to enhance the bone response and mechanical strength of rabbit femoral defects filled with injectable calcium phosphate (CaP)/gelatin microparticle composites. Therefore, TGF-beta1 loa

  2. 椎体成形术或后凸成形术生物活性充填材料的体内降解%The degradation of bioactive bone cement for vertebroplasty or kyphoplasty in vivo

    Institute of Scientific and Technical Information of China (English)

    朱雪松; 陈晓庆; 陈春茂; 王根林; 顾勇; 耿德春; 张志明; 杨惠林

    2010-01-01

    目的 观察磷酸钙骨水泥(CPC)和硫酸钙骨水泥(CSC)在椎体内的演变过程,为椎体成形术或后凸成形术中寻找更为合适的充填材料.方法 对24只成年雌性绵羊的L2~L5椎体制作骨缺损,随机注入CPC、CSC和聚甲基丙烯酸甲酯(PMMA),其中剩余的椎体作为空白对照,并以L6椎体作正常对照.术后2周、12周和24周分别随机处死其中8只绵羊,进行大体观察、生物力学测试、不脱钙组织学分析.结果 CSC组和CPC组椎体被填充材料明显增强,但CSC组椎体力学性能自2~12周呈现下降趋势,而到24周时又出现回升.CPC组椎体力学性能自2~24周呈上升趋势.12周时3组新骨形成量差异不明显,CSC已被大部分吸收;植入24周时新骨形成量CSC组>空白组>CPC组,CPC出现了明显的吸收,而CSC仅有少量残留.结论 CSC与CPC初期均能明显增强椎体;随着时间的推移,CSC在体内降解迅速,而CPC在体内降解缓慢.%Objective To observe the degradation of calcium phosphate cements (CPC) and calcium sulfate cement (CSC) in vertebras, and explore the ideal filler for vertebroplasty and kyphoplasty.Methods Bone voids were created in L2-L5 vertebras of 24 female mature sheep. CPC, CSC and polymethylmethacrylate (PMMA) were injected into one bone void randomly, and the remaining voids served as the blank control, and L6 vertebra served as the normal control. Eight sheep were sacrificed at the 2nd,12th and 24th week after operation randomly. Gross observation, biomechanical test and undecalcified bone histology analyses were performed. Results Biomechanical analysis showed that the vertebras could be augmented by CPC and CSC. The mechanical properties of CSC group were decreased from the 2nd to 12th week, and increased from the 12th to 24th week after operation. The mechanical properties of CPC group were increased from the 2nd to 24th week, however, but lower than PMMA group. Histology analysis revealed CSC was mostly

  3. The clinical effects of osteoporosis of lumbar degenerative disease by injectable calcium sulfate bone cement to strengthen pedicle screw internal fixation%骨质疏松腰椎退行性疾病的手术治疗分析

    Institute of Scientific and Technical Information of China (English)

    孔祥瑞; 刘德政; 刘海峰; 杨计策; 赵志超

    2015-01-01

    ObjectiveTo explore the clinical effects of osteoporosis of lumbar degenerative disease by injectable calcium sulfate bone cement to strengthen pedicle screw internal fixation. Methods 82 cases of patients with lumbar degenerative dis-ease of osteoporosis word randomly divided into experiment group(41 cases) and control group(41 cases). The control group were treated by transpedicle screws fixation, the experiment group were treated by injectable calcium sulfate bone cement to strengthen pedicle screw internal fixation. The time of operation, mean bleeding volum, the scores of VAS, ODI, JOA were com-pared for the two groups. ResultsThe time of operation, mean bleeding volum for the experiment group were better than the control group; There was no significant difference on the scores of VAS, ODI, JOA; The scores of VAS, ODI for the experiment group were lower than the control group postoperation for 1 week, 2 months, 12 months; The scores of JOA for the experiment group were higher than the control group postoperation for 1 week, 2 months, 12 months. ConclusionIt can improve the scores of VAS, ODI, JOA for the patients with osteoporosis of lumbar degenerative disease by injectable calcium sulfate bone cement to strengthen pedicle screw internal fixation. It is worthy of clinical promotion.%目的:探讨可注射硫酸钙骨水泥强化椎弓根钉内固定治疗骨质疏松腰椎退行性疾病的临床疗效。方法:按照随机数字表法将我院收治的82例骨质疏松腰椎退行性疾病患者均分为实验组和对照组,对照组给予单纯椎弓根内固定治疗,实验组给予可注射硫酸钙骨水泥强化椎弓根钉内固定治疗。比较两组患者手术时间、术中出血量以及治疗前后疼痛视觉模拟评分(VAS)、Oswestry 功能障碍指数(ODI)、JOA 腰椎病疗效评分变化情况。结果:实验组患者手术时间和术中出血量显著高于对照组;两组患者术前 VAS 评分、ODI 评分、JOA

  4. Biomechanics study on the femoral neck with side hole hollow nail combined with bone cement%股骨颈带侧孔空心钉添加骨水泥的生物力学实验探究

    Institute of Scientific and Technical Information of China (English)

    闫作

    2014-01-01

    objective To study the healing effects by applying femoral neck with side hole hollow nail combined with bone cement for the promotion of fracture.Methods 58 adult femoral neck specimens were seletced based on the maximum axial pull output (F-Max) in experimental group, 12 femoral neck in bored after the hollow screw directly into the center of the axial, the other 12 femoral neck in the center of the axial drilling will polymethacrylate again after infusion of bone cement into side holes with hollow screw. To pull out the experiment, the hollow nail pulling power of the maximum axial and screw in the process of cycle resistance to bending experiment in loose could withstand the maximum load were determined.Results In PMMA bone cement injection hole hollow nail was signiifcantly higher than that of the maximum axial force ,which was higher than pure hollow nail maximum axial pull output, the difference was statistically signiifcant (P<0.05). Conclusion For hip osteoporosis fracture, the side holes by using methyl methacrylate hollow nail ifxed the fracture end, can signiifcantly reduce the risk of femoral head loose, falling off, and improve the stability of the ifxed the fracture end, accelerate fracture healing.%目的:探讨股骨颈带侧孔空心钉添加骨水泥对骨折愈合的促进效果。方法选取58具成人尸体股骨颈标本,依据最大轴向拔出力(F-max)进行实验分组,12个股骨颈在轴向正中钻孔后将空心钉直接置入,另12个股骨颈在轴向正中钻孔将聚甲基丙烯酸酯骨水泥输注后再置入带侧孔空心钉。进行拔出实验,对空心钉最大轴向的拔出力及周期抗屈实验过程中螺钉在松动时所能承受的最大负荷进行测定。结果注入PMMA骨水泥侧孔空心钉最大轴向力显著高于高于单纯空心钉最大轴向拔出力,对比差异有统计学意义(P<0.05)。结论对于髋部骨质疏松骨折来说,采用加入聚甲基丙烯酸甲酯侧孔

  5. Reinforcement of osteosynthesis screws with brushite cement.

    Science.gov (United States)

    Van Landuyt, P; Peter, B; Beluze, L; Lemaître, J

    1999-08-01

    The fixation of osteosynthesis screws remains a severe problem for fracture repair among osteoporotic patients. Polymethyl-methacrylate (PMMA) is routinely used to improve screw fixation, but this material has well-known drawbacks such as monomer toxicity, exothermic polymerization, and nonresorbability. Calcium phosphate cements have been developed for several years. Among these new bone substitution materials, brushite cements have the advantage of being injectable and resorbable. The aim of this study is to assess the reinforcement of osteosynthesis screws with brushite cement. Polyurethane foams, whose density is close to that of cancellous bone, were used as bone model. A hole was tapped in a foam sample, then brushite cement was injected. Trabecular osteosynthesis screws were inserted. After 24 h of aging in water, the stripping force was measured by a pull-out test. Screws (4.0 and 6.5 mm diameter) and two foam densities (0.14 and 0.28 g/cm3) were compared. Cements with varying solid/liquid ratios and xanthan contents were used in order to obtain the best screw reinforcement. During the pull-out test, the stripping force first increases to a maximum, then drops to a steady-state value until complete screw extraction. Both maximum force and plateau value increase drastically in the presence of cement. The highest stripping force is observed for 6.5-mm screws reinforced with cement in low-density foams. In this case, the stripping force is multiplied by 3.3 in the presence of cement. In a second experiment, cements with solid/liquid ratio ranging from 2.0 to 3.5 g/mL were used with 6.5-mm diameter screws. In some compositions, xanthan was added to improve injectability. The best results were obtained with 2.5 g/mL cement containing xanthan and with 3.0 g/mL cements without xanthan. A 0.9-kN maximal stripping force was observed with nonreinforced screws, while 1.9 kN was reached with reinforced screws. These first results are very promising regarding screw

  6. Biomechanical analysis of a novel perfusional pedicle screw augmentation with bone cement in osteo-porotic vertebra%可灌注骨水泥椎弓根螺钉的生物力学研究

    Institute of Scientific and Technical Information of China (English)

    杨惠林; 王志荣; 王根林; 朱若夫; 吴树华; 王以进; 唐天驷

    2009-01-01

    Objective To clarify the biomechanical stability of novel perfusional pedicle screw (NPPS) in spinal vertebrae with osteoporosis. Methods Forty-two vertebrae (T to L) obtained from 6 for-malin preserved cadavers (5 males and 1 females; mean age, 73 years) were used. The mean bone mineral density was (0.696±0.14) g/cm2. The NPPS was inserted into one pediele of each vertebra, then early-dough-time cement 2 ml was perfused with the bone cement pusher and perfusion tube under X-ray into the verte-bra body through the hollow part of NPPS, and the control screw, an improved CD2 screw, was inserted into the contralateral pedicle. Three vertebrae were chose to observe the distribution of cement, and the other 39 vertebrae were randomly divided into three groups to make the pull-out test, rotating-out torque test, and cyclic bending resistance test respectively. Ten novel perfusional pedicle screws and ten control screws were respectively examined by three-point bend test. Results Cement perfused around the side holes of the distal screw in all vertebral body and no cement leakage occurred. The mean maximum force at pull-out was (760± 178) N for the NPPS and (355±87) N for the control screw. The mean maximum rotating-out torque was (1.347±0.377) N'm for the NPPS and (0.488±0.205) N'm for the control screw. In cyclic bending resistance test, the NPPS was found to withstand a greater number of cycles or greater loading before loosening. About 30.8% (4/13) of the NPPS became loosing (displacement>2.000 mm), the mean load of the loosening screws was (150±46) N and the mean displacement of the non-loosening screws was (0.661±0.289) mm. All of the control screws were loosening among 50-200 N before 800 cycles. Conclusion The manipulation of NPPS is simple with the application of cement pusher and perfusion tube. It is effective in the control of cement leakage and could enhance the fixation stability of the pedicel screw significantly in osteoporotic vertebrae. The

  7. [Cement augmentation of pedicle screws : Pros and cons].

    Science.gov (United States)

    Schnake, K J; Blattert, T R; Liljenqvist, U

    2016-09-01

    Cement augmentation of pedicle screws biomechanically increases screw purchase in the bone. However, clinical complications may occur. The pros and cons of the technique are discussed from different clinical perspectives. PMID:27514827

  8. Calcium phosphate cement reinforcement by polymer infiltration and in situ curing: a method for 3D scaffold reinforcement.

    Science.gov (United States)

    Alge, Daniel L; Chu, Tien-Min Gabriel

    2010-08-01

    This study describes a novel method of calcium phosphate cement reinforcement based on infiltrating a pre-set cement with a reactive polymer and then cross-linking the polymer in situ. This method can be used to reinforce 3D calcium phosphate cement scaffolds, which we demonstrate using poly(ethylene glycol) diacrylate (PEGDA) as a model reinforcing polymer. The compressive strength of a 3D scaffold comprised of orthogonally intersecting beams was increased from 0.31 +/- 0.06 MPa to 1.65 +/- 0.13 MPa using PEGDA 600. In addition, the mechanical properties of reinforced cement were characterized using three PEGDA molecular weights (200, 400, and 600 Da) and three cement powder to liquid (P/L) ratios (0.8, 1.0, and 1.43). Higher molecular weight increased reinforcement efficacy, and P/L controlled cement porosity and determined the extent of polymer incorporation. Although increasing polymer incorporation resulted in a transition from brittle, cement-like behavior to ductile, polymer-like behavior, maximizing polymer incorporation was not advantageous. Polymerization shrinkage produced microcracks in the cement, which reduced the mechanical properties. The most effective reinforcement was achieved with P/L of 1.43 and PEGDA 600. In this group, flexural strength increased from 0.44 +/- 0.12 MPa to 7.04 +/- 0.51 MPa, maximum displacement from 0.05 +/- 0.01 mm to 1.44 +/- 0.17 mm, and work of fracture from 0.64 +/- 0.10 J/m(2) to 677.96 +/- 70.88 J/m(2) compared to non-reinforced controls. These results demonstrate the effectiveness of our novel reinforcement method, as well as its potential for fabricating reinforced 3D calcium phosphate cement scaffolds useful for bone tissue engineering. PMID:20186776

  9. 21 CFR 888.3790 - Wrist joint metal constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Wrist joint metal constrained cemented prosthesis... constrained cemented prosthesis. (a) Identification. A wrist joint metal constrained cemented prosthesis is a... as cobalt-chromium-molybdenum, and is limited to those prostheses intended for use with bone...

  10. Safety and efficacy of additive and subtractive surface modification of Ti6Al4V endosseous implant in goat bone.

    Science.gov (United States)

    Mistry, Surajit; Roy, Subhasis; Jyoti Maitra, Nilendu; Roy, Rajiv; Datta, Someswar; Chanda, Abhijit; Sarkar, Soumya

    2016-04-01

    Growing interest of endosseous implant research is focused on surface modification to achieve early and strong osseointegration. The present study compared the behaviour of hydroxyapatite coated, zinc doped hydroxyapatite coated and hydrothermally treated titanium (Ti6Al4V) with machined Ti6Al4V implants (control) on osseointegration. The surface characterization and bacterial affinity test for implants were performed. Forty eight (48) cylinders (4 types in each animal) were placed in the humerus bone of 12 black Bengal goats. Bone-implant interface was examined with histological, radiological parameters and scanning electron microscopy on 42nd, 90th, and 180th day post-implantation. Surface roughness alterations of bone-detached implants with time were analyzed by non-contact profilometer. Push-out test (90th day) was performed to assess the strength of bony integration of implants. The coated implants revealed direct and early bone-implant contact but high bacterial affinity and coating resorption/cracks. Low bacterial affinity and strongest osseointegration was observed with hydrothermally treated implants. Poor bacterial affinity and delayed but strong fixation were evident with control implant. Based on the results of laboratory and animal experiments, we conclude that the hydrothermal modification of titanium implant is the more suitable way to achieve safe and effective osseointegration than the other three implant types for endosseous application. PMID:26705934

  11. DMTA method in determining strength parameters of acrylic cements

    Directory of Open Access Journals (Sweden)

    J. Koszkul

    2007-05-01

    Full Text Available Purpose: The paper presents the results of investigations of dynamic properties for bone cement with different fillers by means of DMTA method. Addition of any substance causes the change in mechanical properties. Pure PALAMED® material and material filled with four different fillers have been analysed.Design/methodology/approach: One of the methods of thermal analysis for polymeric materials has been used for investigations. DMTA method is based on the analysis of the signal (reaction from the deformed material under particular conditions, at the changeable ambient temperature as well as vibrations frequency and amplitude. DMTA thermograms give information on change in storage modulus E’ and the mechanical loss factor tgδ, which is responsible for dissipation of energy during deformation. Pure cement as well as the cement filled with: BiO-OSS and PORESORB bone graft substitute materials, Al2O3 ceramic material and powdered animal bones. Method of specimen preparation and proportion in which the specimens were prepared are presented in the text.Practical implications: As it results from the literature analysis, no investigations of such a wide group of fillers, both organic and inorganic have been carried out yet. The investigations enabled the storage modulus and tgδ to be determined for each of the prepared materials, thus to indicate the material whose properties enable this material to be used in further alloplasty surgeries for hip joint. Practical application of the results of the investigations described in this paper will be possible after long and comprehensive clinical trials.Originality/value: Original value of this paper are the results of tests since such an analysis has never been conducted by scientific environment working on this subject.

  12. Influence of relation CaO/SiO{sub 2} mixtures of anhydrous cement and mineral additives on the formation of CSH and combat the retrogression; Influencia da relacao CaO/SiO{sub 2} de misturas anidras de cimento e aditivos minerais na formacao do C-S-H e no combate a retrogressao

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, Marcos A.S. [Instituto Federal de Educacao, Ciencia e Tecnologia do Rio Grande do Norte (IFRN), Natal, RN (Brazil); Martinelli, Antonio E.; Melo, Dulce M.A.; Souza, Pablo P.D. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Renovato, Tiago

    2012-07-01

    Temperatures above de 110 deg C cause cracks in the cement placed on the annular, and lost of hydraulic insulation; this crack is occasioned by the phenomenon of retrogression of the compressive resistance due to the conversion of the hydrated calcium silicate in phases calcium-rich, caused by the high temperatures in the wells. This paper presents the results of an experimental study aimed to investigate the influence of the molar ratio of different mixtures CaO/SiO{sub 2} Portland cement (CP) and minerals additives in the formation of CSH and retrogression of cement slurries subjected to high temperature and pressure. For both cement slurries were formulated with the addition of sugarcane biomass waste, silica flour and metakaolin in different concentrations of additives. The results of compressive strength and XRD showed that the use of cement slurries with molar ratio CaO/SiO{sub 2} near one can minimize the effect of retrogression when pulps are subjected to temperatures of 280 deg C and 17.2 MPa. (author)

  13. 骨水泥钉道强化联合空心侧孔椎弓根螺钉治疗伴骨质疏松症的腰椎退行性病变的临床疗效观察%Comparison of the clinical effect of PMMA bone cement augmented screw passageway and bone cement-injectable cannulated pedicle screw in treatment of degenerative lumbar disease with osteoporosis

    Institute of Scientific and Technical Information of China (English)

    刘松明; 宋洁富; 荆志振

    2016-01-01

    目的:比较空心侧孔椎弓根螺钉和骨水泥钉道( PMMA)强化方法应用于伴骨质疏松症的腰椎退行性病变的临床效果。方法选取伴骨质疏松症的腰椎退行性病变患者48例,男21例,女27例;年龄54~78岁,平均64.5岁。其中腰椎管狭窄症17例,腰椎间盘突出症18例,退行性腰椎滑脱症8例,腰椎退行性侧凸5例。按手术方式分为两组,A组23例采用空心侧孔椎弓根螺钉+PMMA。 B组25例采用PMMA行钉道强化+普通椎弓根螺钉内固定术。比较两组手术时间、出血量、住院时间。采用疼痛视觉模拟量表( visual analogue scale,VAS)评分,Oswestry功能障碍指数( Oswestry disability index,ODI)评价患者术后疼痛和功能恢复情况。术前及术后1、3、6、12个月及术后每年行X线检查评估椎间隙高度丢失、内固定失败率和椎间植骨融合率。结果48例患者均得到随访,随访时间1~3.5年。 A组手术时间、出血量、住院时间显著优于B组(均P<0.05)。 A组、B组植骨融合率分别为92.1%、91.2%,两组差异无统计学意义( P>0.05)。A组发生螺钉断裂1例,B组未出现此类情况(P<0.05)。 B组发生内固定松动、螺钉拔出内固定失败1例, A组未发生此类情况(P<0.05)。 A组椎间隙高度丢失(2.7±1.7)mm,B组椎间隙高度丢失(3.7±2.1)mm,两组差异有统计学意义(P<0.05)。根据VAS评分和ODI,两组患者术后疼痛与功能均得到改善,A组效果优于B组(均P<0.05)。结论空心侧孔椎弓根螺钉+PMMA强化内固定用于伴骨质疏松症的腰椎退行性病变是一种具有较好安全性和有效性的方法。%Objective To compare the clinical effect of PMMA bone cement augmented screw passageway and bone cement-injectable cannulated pedicle screw in treatment of degenerative lumbar disease with osteoporosis. Methods

  14. Increased antibiotic release and equivalent biomechanics of a spacer cement without hard radio contrast agents.

    Science.gov (United States)

    Bitsch, R G; Kretzer, J P; Vogt, S; Büchner, H; Thomsen, M N; Lehner, B

    2015-10-01

    We compared a novel calcium carbonate spacer cement (Copal® spacem) to well-established bone cements. Electron microscopic structure and elution properties of the antibiotics ofloxacin, vancomycin, clindamycin, and gentamicin were examined. A knee wear simulator model for articulating cement spacers was established. Mechanical tests for bending strength, flexural modulus, and compressive and fatigue strength were performed. The electron microscopic analysis showed a microporous structure of the spacer cement, and this promoted a significantly higher and longer antibiotic elution. All spacer cement specimens released the antibiotics for a period of up to 50days with the exception of the vancomycin loading. The spacer cement showed significantly less wear scars and fulfilled the ISO 5833 requirements. The newly developed spacer cement is a hydrophilic antibiotic carrier with an increased release. Cement without hard radio contrast agents can improve tribological behaviour of spacers, and this may reduce reactive wear particles and abrasive bone defects. PMID:26219491

  15. Comparative study of bone cement injectable canulated pedicle screw and conventional screw path-augmentation with bone cement in treatment of lumbar spondylolisthesis with osteoporosis%新型可注射骨水泥椎弓根螺钉与骨水泥钉道强化在治疗腰椎滑脱伴骨质疏松中的比较研究

    Institute of Scientific and Technical Information of China (English)

    代飞; 刘瑶瑶; 孙东; 徐美涛; 许建中

    2014-01-01

    目的:比较新型可注射骨水泥椎弓根螺钉( bone cement injectable canulated pedicle screw , CICPS)和传统骨水泥钉道强化方法应用于治疗腰椎滑脱伴骨质疏松患者的临床疗效。方法2011年7月~2013年11月序贯纳入腰椎滑脱伴骨质疏松患者( T<-2.5)43例,随机分为2组,A组20例采用CICPS行后路滑脱复位植骨融合内固定术。B组23例采用传统骨水泥钉道强化内固定术。比较2组手术时间、出血量、住院时间。采用疼痛视觉模拟量表(visual analogue scale, VAS)评分,Oswestry功能障碍指数(Oswestry disability index, ODI)评价患者术后疼痛和功能恢复。术前及术后1、3、6、12个月及术后每年行X线和CT检查评估椎间隙高度丢失、内固定失败率和椎间植骨融合率。结果43例患者均得到随访,随访时间为6~33个月,平均16.5个月。 A组手术时间、出血量、住院时间显著低于B组(P<0.05)。 A组和B组植骨融合率分别为94.6%、90.2%,2组比较差异无统计学意义(P>0.05)。 B组发生内固定松动、螺钉拔出3例,A组未发生此类情况。A组椎间隙高度丢失(2.3±1.2)mm,B组椎间隙高度丢失(3.6±2.2) mm,2组比较差异有统计学意义(P<0.05)。根据VAS评分和ODI,2组患者术后疼痛与功能均得到改善,A组效果优于B组(P<0.05)。结论 CICPS强化内固定稳定性是一种具有较好安全性和有效性的新方法。%Objective To compare the clinical effect of bone cement injectable canulated pedicle screw (CICPS) and conven-tional screw path-augmentation with bone cement in the treatment of lumbar spondylolisthesis with osteoporosis patients.Methods From July 2011 to November 2013, sequential 43 patients with osteoporosis (T≤-2.5) and lumbar spondylolisthesis were randomly divided into 2 groups.Group A of 20 cases were treated with CICPS and group B of

  16. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.; Glasser, Fred P.

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements are...

  17. Combination of modified mixing technique and low frequency ultrasound to control the elution profile of vancomycin-loaded acrylic bone cement

    Science.gov (United States)

    Wendling, A.; Mar, D.; Wischmeier, N.; Anderson, D.

    2016-01-01

    Objectives The objective of this study was to determine if combining variations in mixing technique of antibiotic-impregnated polymethylmethacrylate (PMMA) cement with low frequency ultrasound (LFUS) improves antibiotic elution during the initial high phase (Phase I) and subsequent low phase (Phase II) while not diminishing mechanical strength. Methods Three batches of vancomycin-loaded PMMA were prepared with different mixing techniques: a standard technique; a delayed technique; and a control without antibiotic. Daily elution samples were analysed using flow injection analysis (FIA). Beginning in Phase II, samples from each mix group were selected randomly to undergo either five, 15, 45, or 0 minutes of LFUS treatment. Elution amounts between LFUS treatments were analysed. Following Phase II, compression testing was done to quantify strength. A-priori t-tests and univariate ANOVAs were used to compare elution and mechanical test results between the two mix groups and the control group. Results The delayed technique showed a significant increase in elution on day one compared with the standard mix technique (p DOI: 10.1302/2046-3758.52.2000412 PMID:26843512

  18. Influência de aditivos sobre a trabalhabilidade de concretos refratários de ultra-baixo teor de cimento Influence of additives on the working time of ultra-low cement refractory castables

    Directory of Open Access Journals (Sweden)

    I. R. de Oliveira

    2003-03-01

    Full Text Available A trabalhabilidade de concretos refratários é determinada principalmente pela cinética de hidratação do ligante hidráulico. Têm-se observado que o processo de gelificação/hidratação desse material em meio aquoso é sensivelmente influenciado pela presença de aditivos dispersantes. Em virtude disso, este trabalho investigou a correlação entre a trabalhabilidade de concretos refratários de ultra-baixo teor de cimento no sistema Al2O3-SiC-SiO2-C e as características apresentadas por suspensões aquosas de cimento na presença de diferentes aditivos. A influência desses aditivos no processo de hidratação do cimento foi estudada através de ensaios de microscopia eletrônica de varredura, difração de raios X, sedimentação, condutividade elétrica e ensaios reológicos. Os resultados obtidos indicam que a "pega" inicial do concreto ocorre devido à aglomeração das partículas induzida pela formação de um produto coloidal amorfo ("gel" entre elas. Observou-se que o citrato de sódio favorece a formação de uma quantidade significativa de "gel" entre as partículas, reduzindo a trabalhabilidade do concreto.The working time of refractory castables is mainly determined by the hydration kinetic of the hydraulic binder. It has been observed that the gelation/hydration process of this material in aqueous solutions is significantly influenced by the addition of dispersing additives. Hence, this work investigated the correlation between the working time of ULC refractory castables in the Al2O3-SiC-SiO2-C system and the physic-chemical characteristics of cement aqueous suspensions in the presence of different sort of additives. The influence of these additives in the cement hydration process was studied by scanning electron microscopy, X-ray diffraction, sedimentation experiments, electrical conductivity and rheological tests. The initial setting of castables was found to be associated to particle coagulation and the development of

  19. Early experience of SPECT/CT Co-registration in bone scans for characterization of skeletal lesions in metastatic workup: additional confidence wherever required

    International Nuclear Information System (INIS)

    Full text: Whenever SPECT/CT hybrid machines are available, the usefulness of combining functional data with anatomical data, the so called hybrid or fusion imaging is well established. However at centers working on plain gamma cameras this is not an option available. We intended to evaluate the practical usefulness of manual co-registration of bone SPECT images on a plain gamma camera and CT images of the same region in for lesion characterization mostly referred for detection of skeletal metastasis at our new centre. Materials and Methods: Of the total of 126 consecutive bone scans referred for metastatic workup at our new centre, 10 selected patients having 16 suspicious vertebral lesions were evaluated. 99mTc MDP whole body planar bone scans with a regional SPECT study followed by a regional non contrast CT- scan was done separately using appropriate markers for landmark identification during fusion and images fused using software and evaluated to look for difference in outcome of SPECT images alone versus fused images. Results: Of the 16 lesions 10 lesions were characterized correctly on planar and SPECT images alone by pattern recognition and localization on vertebrae with confirmation of findings but no additional benefit offered by CT evaluation. In 6 lesions (37.5%) doubt was cleared by additional information provided by CT and thus actual correct characterization into benign or metastatic lesion. Conclusion: It may be possible in most cases to characterize the lesions on SPECT and planar bone scan images alone using usual pattern identification and regional uptake on vertebrae. However, addition of CT co registration was helpful in a significant number (35%) of doubtful lesions. We would thus recommend not all but selected doubtful lesions for CT co-registration, when using a plain gamma camera without integrated CT. This would be cost-effective and more practicable. However, this would be good for integrated systems as well if radiation exposure is

  20. UTILIZATION OF AGARWOOD DISTILLATION WASTE IN OILWELL CEMENT AND ITS EFFECT ON FREE WATER AND POROSITY

    OpenAIRE

    Arina Sauki; Muhammad Hazman Md. Shahid; Ku Halim Ku Hamid; Azlinda Azizi; Siti Khatijah Jamaludin; Tengku Amran Tengku Mohd; Nur Hashimah Alias

    2013-01-01

    The intent of this research is to utilize the waste produced by distillation process of Agarwood oil and convert it into a profitable oilwell cement additive. Common problem during oilwell cementing is free wáter separation. This problem could weaken cement at the top, gas migration problem and non uniform density of cement slurry that are even worst in cementing deviated well. Another concern on cementing design is the porosity of the hardened cement. If the cement is too porous, it can lead...

  1. 兔股骨节段缺损模型研究磷酸钙骨水泥骨愈合性能%Bone Healing Capacity of Calcium Phosphate Cement Cylinder in a Rabbit Femur Segmental Defect Model

    Institute of Scientific and Technical Information of China (English)

    王大伟; 潘朝晖; 赵玉祥; 栾兆新

    2015-01-01

    Objective:To investigate the bone healing capacity of calcium phosphate cement ( CPC) cylinder in a rabbit femur seg-mental defect model by comparing the influence of muscle or periosteum as wrapping material.Methods: Pre-hardened CPC cylinder was prepared.Three specimens were analyzed by scanning electron microscopy and X-ray diffraction to characterize its microstructure and chemical composition.Sixty adult rabbits were randomly assigned to four groups,then received a defect size of 15 mm osteotomy within the femurs.The 8-hole plate was fixed with three screws in the proximal and distal part of the defect, respectively.In group A, the fem-oral defects were left alone;in group B, the defects with retained periosteum; in group C, the defects were grafted with CPC cylinder wrapped by muscle;and in group D, the defects were grafted with CPC cylinder wrapped by periosteum.Five rabbits from each group were sacrificed at 4, 8 and 12 weeks postoperatively.The samples were evaluated with radiological, biomechanical and histological meth-ods.Results:Irregular particles were seen on the surface of specimens, the pore size was approximately 10 μm.The peak locations for the hydroxyapatite were seen in the X-ray diffraction patterns of the specimens.Group A showed a few radiographic evidence of new bone formation within the boundary of the defect at 4 weeks.Three bone defects bridged at 8 weeks and 4 bone defects bridged at 12 weeks. Group B showed radiographic evidence of new bone formation at 4 weeks.Four bone defects bridged at 8 weeks and 5 bone defects bridged at 12 weeks.Group C showed discernable interface between the CPC cylinder and both femoral cut ends at 4 weeks, which became invisi-ble at 8 weeks.Defects bridged by continuous callus beside the CPC cylinder in 4 rabbits and completely surrounded in 1 rabbit at 12 weeks.Group D showed better quality of new bone formation, the CPC cylinders were surrounded by new bone at 12 weeks.However, all CPCs retained their

  2. Spatial analysis of cement production and consumption in Turkey

    OpenAIRE

    Beygo, Cem; Cakmak, Goksenin

    1998-01-01

    After 1950?s, the rapid urbanization of Turkey stimulated the production and consumption of cement and the number of cement factories increased since then. In addition, construction of highways, bridges, dams and industrialization also contribute to the consumption of cement. Construction industry became a locomotif of the economy of the country and cement industry is the most element of the construction industry. This study analyzes the growth of population and urbanization according to new ...

  3. Stability evaluation for cement package containing radioactive waste

    International Nuclear Information System (INIS)

    In order to provide stable cement packages, ettringite formation, a major cause of cement deterioration, was studied theoretically and experimentally. A computer program was developed to calculate the chemical equilibrium compositions of a complex cement system. Higher curing temperature and the addition of NaOH were identified as effective methods to avoid ettringite formation. These findings were confirmed by measuring the amount of ettringite in solidified cement by an X-ray diffraction method

  4. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    speciation of silicon at pH 10 has a significant impact upon the solubility of montmorillonite and would thus constitute a logical choice of pH limit for cement-derived pore fluids, but it is unlikely that cement-based grouts could be developed to meet this limit. Control of mass transport by diffusion processes serves as a significant constraint over the amount of bentonite that can be degraded. Computer simulations indicate that porosity reduction is likely at the interface between cement and bentonite. However, it is not clear how the transport properties of bentonite may be modified due to mineral alteration processes. There are considerable uncertainties concerning the precise mechanism of the rate of montmorillonite dissolution at elevated pH. The rate of dissolution may be inhibited by the presence of dissolved Si (and perhaps Al), but this mechanism has yet to be confirmed at high pH. The type of secondary minerals assumed to form from cement-bentonite interaction will also have a significant impact upon the rate of montmorillonite dissolution. Low-pH cement systems have received little attention thus far regarding the development of models for the chemical evolution of pore fluids. Low Ca/Si CSH gels show preferential leaching of Si, which is in marked contrast with gels of greater Ca/Si ratio. Models apparently capable of predicting pore fluid composition coexisting with low Ca/Si CSH gels are a modified Berner model and a solid-solution model proposed by Sugiyama and Fujita. The solubility of silica in pore fluids coexisting with low Ca/Si gels may exceed that of amorphous silica, and may pose problems regarding the stability of montmorillonite in relation to framework silicates such as feldspars. However, the potential rate of conversion of montmorillonite to feldspar under repository conditions is uncertain. It is necessary to use additives such as super plasticiser to improve the workability of low-pH cements. These organic additives have the potential to

  5. Low pH Cements

    International Nuclear Information System (INIS)

    speciation of silicon at pH 10 has a significant impact upon the solubility of montmorillonite and would thus constitute a logical choice of pH limit for cement-derived pore fluids, but it is unlikely that cement-based grouts could be developed to meet this limit. Control of mass transport by diffusion processes serves as a significant constraint over the amount of bentonite that can be degraded. Computer simulations indicate that porosity reduction is likely at the interface between cement and bentonite. However, it is not clear how the transport properties of bentonite may be modified due to mineral alteration processes. There are considerable uncertainties concerning the precise mechanism of the rate of montmorillonite dissolution at elevated pH. The rate of dissolution may be inhibited by the presence of dissolved Si (and perhaps Al), but this mechanism has yet to be confirmed at high pH. The type of secondary minerals assumed to form from cement-bentonite interaction will also have a significant impact upon the rate of montmorillonite dissolution. Low-pH cement systems have received little attention thus far regarding the development of models for the chemical evolution of pore fluids. Low Ca/Si CSH gels show preferential leaching of Si, which is in marked contrast with gels of greater Ca/Si ratio. Models apparently capable of predicting pore fluid composition coexisting with low Ca/Si CSH gels are a modified Berner model and a solid-solution model proposed by Sugiyama and Fujita. The solubility of silica in pore fluids coexisting with low Ca/Si gels may exceed that of amorphous silica, and may pose problems regarding the stability of montmorillonite in relation to framework silicates such as feldspars. However, the potential rate of conversion of montmorillonite to feldspar under repository conditions is uncertain. It is necessary to use additives such as super plasticiser to improve the workability of low-pH cements. These organic additives have the potential to

  6. Cementation of Loose Sand Particles based on Bio-cement

    Institute of Scientific and Technical Information of China (English)

    RONG Hui; QIAN Chunxiang

    2014-01-01

    Loose sand particles could be cemented to sandstone by bio-cement (microbial induced magnesium carbonate). The bio-sandstone was firstly prepared, and then the compressive strength and the porosity of the sandstone cemented by microbial induced magnesium carbonate were tested to characterize the cementation effectiveness. In addition, the formed mineral composition and the microstructure of bio-sandstone were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The experimental results show that the feasibility of binding loose sand particles using microbial induced magnesium carbonate precipitation is available and the acquired compressive strength of bio-sandstone can be excellent at certain ages. Moreover, the compressive strength and the porosity could be improved with the increase of microbial induced magnesium carbonate content. XRD results indicate that the morphology of magnesium carbonate induced by microbe appears as needles and SEM results show that the cementation of loose sand particles to sandstone mainly relies on the microbial induced formation of magnesium carbonate precipitation around individual particles and at particle-particle contacts.

  7. Influence of the tibial stem design on bone density after cemented total knee arthroplasty: a prospective seven-year follow-up study.

    Science.gov (United States)

    Hernandez-Vaquero, Daniel; Garcia-Sandoval, Manuel A; Fernandez-Carreira, Jose M; Gava, Richard

    2008-02-01

    We prospectively measured the changes in bone mineral density (BMD) in the proximal tibia of 20 total knee arthroplasties, ten with cruciform stems and ten with cylindrical stems. The measurements were made one, four and seven years after surgery. We observed a uniform density decrease in three regions of interest from one to seven years of follow-up. Cylindrical stems showed an asymmetrical density decrease between the three regions of interest, with no change in the central region, a slight decrease in the lateral region, and large decrease in the medial region. Multivariate analysis with general linear model showed the stem type factor as statistically significant for medial region of interest (p = 0.006). The cylindrical stem produces heterogeneous BMD changes under the tibial platform in knee arthroplasties, and this could be a potential risk factor for asymmetrical subsidence of this component. PMID:17115154

  8. Evaluation of the chemical modifications in petroleum asphalt cement with the addition of polypropylene; Avaliacao das modificacoes quimicas no cimento asfaltico de petroleo com a adicao de polipropileno

    Energy Technology Data Exchange (ETDEWEB)

    Marcondes, C.P.; Sales, M.J.A.; Resck, I.S., E-mail: mjsales@unb.b [Universidade de Brasilia (LabPol/UnB), DF (Brazil). Inst. de Quimica. Lab. de Pesquisa em Polimeros; Farias, M.M.; Souza, M.V.R. [Universidade de Brasilia (UnB), DF (Brazil). Dept. de Engenharia Civil e Ambiental

    2010-07-01

    Studies show that the common distress mode in the Brazilian highway network are fatigue cracks and plastic deformation, which are associated with the type of material used in the pavement layers, structural project, excessive traffic load and weathering. To minimize these defects, research on modifiers such as polymers, added to asphalt binders have been developed to provide physical, chemical and rheological improvement. This paper investigates chemical modifications of the binders with the addition of PP by FTIR, NMR and DSC. FTIR spectra of pure and modified binder showed no differences in absorption. NMR analysis showed no strong chemical bonds between the binder and PP. DSC curve of PP showed a melting temperature of 160 deg C ({Delta}H = 94J/g) and the pure binder presented an endothermic transition between 20 and 40 deg C ({Delta}H = 2J/g). In the DSC curves of mixtures, these transitions are not significant, indicating possible interactions between asphalt binder and PP. (author)

  9. INFLUENCE OF WINE ACID ON RHEOLOGICAL PROPERTIES OF WELL BORE CEMENT SLURRIES AND HARDENED CEMENT PROPERTIES

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1989-12-01

    Full Text Available Adaptation of commercial types of domestic cements for use in cementing the deep wells is a process by which Yugoslav oil industry tends to solve problems of completion of those wells independently. In order to design a domestic, cheep and effective retarder, tests of applicability of wine acid on cement slurries have been carried out. Besides examining the necessary wine acid content to achieve desirable Theological properties, the influence of this additive on properties of hardened cement samples has been tested too (the paper is published in Croatian.

  10. Conditioning of radioactive waste solutions by cementation

    International Nuclear Information System (INIS)

    For the cementation of the low and intermediate level evaporator concentrates resulting from the reprocessing of spent fuel numerous experiments were performed to optimize the waste form composition and to characterize the final waste form. Concerning the cementation process, properties of the waste/cement suspension were investigated. These investigations include the dependence of viscosity, bleeding, setting time and hydration heat from the waste cement slurry composition. For the characterization of the waste forms, the mechanical, thermal and chemical stability were determined. For special cases detailed investigations were performed to determine the activity release from waste packages under defined mechanical and thermal stresses. The investigations of the interaction of the waste forms with aqueous solutions include the determination of the Cs/Sr release, the corrosion resistance and the release of actinides. The Cs/Sr release was determined in dependence of the cement type, additives, setting time and sample size. (orig./DG)

  11. Cemented total hip prosthesis: Radiographic and scintigraphic evaluation

    International Nuclear Information System (INIS)

    Conventional radiographs, technetium-99m bone scans, and gallium-67 scans were reviewed in 44 patients who had undergone cemented total hip joint replacement and were imaged because of suspicion of prosthesis loosening or infection. A complete radiolucent line of 2 mm or wider along the bone-cement interface or metal-cement lucency on conventional radiographs was used as the criterion for prosthetic loosening with or without infection and proved to be 54% sensitive and 96% specific. Scintigraphic criteria for prosthetic loosening were increased focal uptake of the radiopharmaceutical for the femoral component and increased focal or diffuse uptake for the acetabular component. For bone scintigraphy, sensitivity was 73% and specificity was 96%. Combining the results of conventional radiographs and bone scans increased sensitivity to 84% and decreased specificity to 92% for the diagnosis of loosening, infection, or both. The study also showed that Ga-67 scintigraphy has a low sensitivity for the detection of infection

  12. Preliminary experimental results of radiofrequency-cement-augmented and cannulated pedicle screws

    Directory of Open Access Journals (Sweden)

    Goost H

    2011-01-01

    Full Text Available The risk of cut-out of a pedicle screw is high in the presence of osteoporotic bone. In cadaver studies it was found that cement augmentation of pedicle screws markedly increases pullout forces. However, the use of conventional low viscosity vertebroplasty or kyphoplasty cement is associated with the risk of cement extravasation. The risk might be reduced by using high viscosity, radiofrequency-activated bone cement. After performing DEXA scans, six fresh-frozen vertebral bodies of different bone densities were obtained from cadavers. Two pedicle screws (WSI Expertise-Inject, Peter Brehm, Germany were placed in the pedicles. About 3 ml of radiofrequency-activated, ultra-high viscosity cement (ER2 Bone Cement, DFine Europe GmbH, Germany was injected through the right pedicle. The left pedicle screw was left uncemented and served as control. Axial pullout tests were performed using a material testing device (Zwick/Roell Zmartpro, Ulm, Germany. The tests revealed that cementaugmented pedicle screws were able to withstand markedly higher pullout forces. Extravasation of cement did not occur. The value of the study is limited by the fact that only six samples were investigated. Further cadaver studies and clinical evaluation will be needed in the future. However, this pilot study showed that combining cannulated pedicle screws with ultra-high viscosity bone cement is a successful approach. Revision due to cut-out and complications secondary to cement extravasation can be reduced by this method.

  13. Cement strength increment by additional ettringite formation

    Directory of Open Access Journals (Sweden)

    Simeonov, J.

    1974-03-01

    Full Text Available Not availableLa ettringita puede formarse a partir de diferentes materias primas, pero sus tres componentes: CaO, SO3 y AI2O3 deben encontrarse con la suficiente concentración en fase líquida para permitir su formación.

  14. A Comprehensive Study of Osteogenic Calcium Phosphate Silicate Cement: Material Characterization and In Vitro/In Vivo Testing.

    Science.gov (United States)

    Gong, Tianxing; Wang, Zhiqin; Zhang, Yixi; Zhang, Yubiao; Hou, Mingxiao; Liu, Xinwei; Wang, Yu; Zhao, Lejun; Ruse, N Dorin; Troczynski, Tom; Häfeli, Urs O

    2016-02-18

    Vertebral compression fractures can be successfully restored by injectable bone cements. Here the as-yet unexplored in vitro cytotoxicity, in vivo biodegradation, and osteoconductivity of a new calcium phosphate silicate cements (CPSC) are studied, where monocalcium phosphate (MCP; 5, 10, and 15 wt%) is added to calcium silicate cement (CSC). Setting rate and compressive strength of CPSC decrease with the addition of MCP. The crystallinity, microstructure, and porosity of hardened CPSC are evaluated by X-ray diffractometer, Fourier transform infrared spectroscopy, and microcomputed tomography (CT). It is found that MCP reacts with calcium hydroxide, one of CSC hydration products, to precipitate apatite. While the reaction accelerates the hydration of CSC, the formation of calcium silicate hydrate gel is disturbed and highly porous microstructures form, resulting in weaker compressive strength. In vitro studies demonstrate that CPSC is noncytotoxic to osteoblast cells and promotes their proliferation. In the rabbit tibia implantation model, clinical X-ray and CT scans demonstrate that CPSC biodegrades slower and osseointegrates better than clinically used calcium phosphate cement (CPC). Histological studies demonstrate that CPSC is osteoconductive and induces higher bone formation than CPC, a finding that might warrant future clinical studies. PMID:26677175

  15. Neutron Scattering Studies of Cement

    Science.gov (United States)

    Allen, Andrew

    2010-03-01

    Despite more than a century of research, basic questions remain regarding both the internal structure and the role of water in Ordinary Portland cement (OPC) concrete, the world's most widely used manufactured material. Most such questions concern the primary hydration product and strength-building phase of OPC paste, the calcium silicate hydrate (C-S-H) gel. When cement and water are mixed, this phase precipitates as clusters of nanoscale (nearly amorphous) colloidal particles with an associated water-filled inter-particle pore system. Most attempts to characterize the C-S-H gel and the behavior of the associated water involve drying or other processes that, themselves, change the bound water content within and around the gel. Neutron scattering methods do not suffer from this disadvantage. Furthermore, the neutron isotope effect and the neutron's sensitivity to molecular motion have enabled considerable progress to be made in recent years by: (i) determining the C-S-H composition, density and gel structure in small-angle neutron scattering (SANS) H/D contrast variation studies; (ii) elucidating the changing state of water within cement as hydration progresses using quasielastic neutron scattering (QENS); and (iii) measuring the production and consumption of nanoscale calcium hydroxide (CH), a by-product of cement hydration that co-exists with the C-S-H gel, using inelastic neutron scattering (INS). These experiments have provided new insights into the physics and chemistry of cement hydration, and have implications for the design of new concretes with pozzolanic cement additions that are intended to address environmental concerns and sustainability issues.

  16. Glass Polyalkenoate Cements Designed for Cranioplasty Applications: An Evaluation of Their Physical and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Basel A. Khader

    2016-03-01

    Full Text Available Glass polyalkenoate cements (GPCs have potential for skeletal cementation. Unfortunately, commercial GPCs all contain, and subsequently release, aluminum ions, which have been implicated in degenerative brain disease. The purpose of this research was to create a series of aluminum-free GPCs constructed from silicate (SiO2, calcium (CaO, zinc (ZnO and sodium (Na2O-containing glasses mixed with poly-acrylic acid (PAA and to evaluate the potential of these cements for cranioplasty applications. Three glasses were formulated based on the SiO2-CaO-ZnO-Na2O parent glass (KBT01 with 0.03 mol % (KBT02 and 0.06 mol % (KBT03 germanium (GeO2 substituted for ZnO. Each glass was then mixed with 50 wt % of a patented SiO2-CaO-ZnO-strontium (SrO glass composition and the resultant mixtures were subsequently reacted with aqueous PAA (50 wt % addition to produce three GPCs. The incorporation of Ge in the glass phase was found to result in decreased working (142 s to 112 s and setting (807 s to 448 s times for the cements manufactured from them, likely due to the increase in crosslink formation between the Ge-containing glasses and the PAA. Compressive (σc and biaxial flexural (σf strengths of the cements were examined at 1, 7 and 30 days post mixing and were found to increase with both maturation and Ge content. The bonding strength of a titanium cylinder (Ti attached to bone by the cements increased from 0.2 MPa, when placed, to 0.6 MPa, after 14 days maturation. The results of this research indicate that Germano-Silicate based GPCs have suitable handling and mechanical properties for cranioplasty fixation.

  17. Glass Polyalkenoate Cements Designed for Cranioplasty Applications: An Evaluation of Their Physical and Mechanical Properties.

    Science.gov (United States)

    Khader, Basel A; Curran, Declan J; Peel, Sean; Towler, Mark R

    2016-01-01

    Glass polyalkenoate cements (GPCs) have potential for skeletal cementation. Unfortunately, commercial GPCs all contain, and subsequently release, aluminum ions, which have been implicated in degenerative brain disease. The purpose of this research was to create a series of aluminum-free GPCs constructed from silicate (SiO₂), calcium (CaO), zinc (ZnO) and sodium (Na₂O)-containing glasses mixed with poly-acrylic acid (PAA) and to evaluate the potential of these cements for cranioplasty applications. Three glasses were formulated based on the SiO₂-CaO-ZnO-Na₂O parent glass (KBT01) with 0.03 mol % (KBT02) and 0.06 mol % (KBT03) germanium (GeO₂) substituted for ZnO. Each glass was then mixed with 50 wt % of a patented SiO₂-CaO-ZnO-strontium (SrO) glass composition and the resultant mixtures were subsequently reacted with aqueous PAA (50 wt % addition) to produce three GPCs. The incorporation of Ge in the glass phase was found to result in decreased working (142 s to 112 s) and setting (807 s to 448 s) times for the cements manufactured from them, likely due to the increase in crosslink formation between the Ge-containing glasses and the PAA. Compressive (σc) and biaxial flexural (σf) strengths of the cements were examined at 1, 7 and 30 days post mixing and were found to increase with both maturation and Ge content. The bonding strength of a titanium cylinder (Ti) attached to bone by the cements increased from 0.2 MPa, when placed, to 0.6 MPa, after 14 days maturation. The results of this research indicate that Germano-Silicate based GPCs have suitable handling and mechanical properties for cranioplasty fixation. PMID:27023623

  18. Development of an Improved Cement for Geothermal Wells

    Energy Technology Data Exchange (ETDEWEB)

    Trabits, George [Trabits Group, LLC, Wasilla, AK (United States)

    2015-04-20

    After an oil, gas, or geothermal production well has been drilled, the well must be stabilized with a casing (sections of steel pipe that are joined together) in order to prevent the walls of the well from collapsing. The gap between the casing and the walls of the well is filled with cement, which locks the casing into place. The casing and cementing of geothermal wells is complicated by the harsh conditions of high temperature, high pressure, and a chemical environment (brines with high concentrations of carbon dioxide and sulfuric acid) that degrades conventional Portland cement. During the 1990s and early 2000s, the U.S. Department of Energy’s Geothermal Technologies Office (GTO) provided support for the development of fly-ash-modified calcium aluminate phosphate (CaP) cement, which offers improved resistance to degradation compared with conventional cement. However, the use of CaP cements involves some operational constraints that can increase the cost and complexity of well cementing. In some cases, CaP cements are incompatible with chemical additives that are commonly used to adjust cement setting time. Care must also be taken to ensure that CaP cements do not become contaminated with leftover conventional cement in pumping equipment used in conventional well cementing. With assistance from GTO, Trabits Group, LLC has developed a zeolite-containing cement that performs well in harsh geothermal conditions (thermal stability at temperatures of up to 300°C and resistance to carbonation) and is easy to use (can be easily adjusted with additives and eliminates the need to “sterilize” pumping equipment as with CaP cements). This combination of properties reduces the complexity/cost of well cementing, which will help enable the widespread development of geothermal energy in the United States.

  19. ULTRA-LIGHTWEIGHT CEMENT

    International Nuclear Information System (INIS)

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

  20. Effect of ZrO{sub 2} addition on the mechanical properties of porous TiO{sub 2} bone scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Tiainen, Hanna [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, PO Box 1109 Blindern, NO-0317 Oslo (Norway); Eder, Georg [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, PO Box 1109 Blindern, NO-0317 Oslo (Norway); Institute of Medical and Polymer Engineering, Chair of Medical Engineering, Technische Universitaet Muenchen, Boltzmannstrasse 15, 85748 Garching (Germany); Nilsen, Ola [Department of Chemistry, University of Oslo, PO Box 1033 Blindern, NO-0315 Oslo (Norway); Haugen, Havard J., E-mail: h.j.haugen@odont.uio.no [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, PO Box 1109 Blindern, NO-0317 Oslo (Norway)

    2012-08-01

    This study aimed at the investigation of the effect of zirconium dioxide (ZrO{sub 2}) addition on the mechanical properties of titanium dioxide (TiO{sub 2}) bone scaffolds. The highly biocompatible TiO{sub 2} has been identified as a promising material for bone scaffolds, whereas the more bioinert ZrO{sub 2} is known for its excellent mechanical properties. Ultra-porous TiO{sub 2} scaffolds (> 89% porosity) were produced using polymer sponge replication with 0-40 wt.% of the TiO{sub 2} raw material substituted with ZrO{sub 2}. Microstructure, chemical composition, and pore architectural features of the prepared ceramic foams were characterised and related to their mechanical strength. Addition of 1 wt.% of ZrO{sub 2} led to 16% increase in the mean compressive strength without significant changes in the pore architectural parameters of TiO{sub 2} scaffolds. Further ZrO{sub 2} additions resulted in reduction of compressive strength in comparison to containing no ZrO{sub 2}. The appearance of zirconium titanate (ZrTiO{sub 4}) phase was found to hinder the densification of the ceramic material during sintering resulting in poor intergranular connections and thus significantly reducing the compressive strength of the highly porous ceramic foam scaffolds. - Highlights: Black-Right-Pointing-Pointer Open porous scaffold with porosity in the range of 89.0 to 92.8% produced. Black-Right-Pointing-Pointer Adding 1 wt.% of ZrO{sub 2} led to 16% increase in strength without changing porosity. Black-Right-Pointing-Pointer Further ZrO{sub 2} additions resulted in reduced compressive strength versus no ZrO{sub 2}. Black-Right-Pointing-Pointer Presence of zirconium titanate (ZrTiO{sub 4}) phase found to hinder the densification. Black-Right-Pointing-Pointer Appearance of ZrTiO{sub 4} resulted in poor intergranular connections.

  1. Energy economy and industrial ecology in the Brazilian cement sector; Economia de energia e ecologia industrial no setor cimenteiro brasileiro

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Marina Elisabete Espinho; Schaeffer, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Planejamento Energetico]. E-mail: marinatavares@openlink.com.br; roberto@ppe.ufrj.br

    1999-07-01

    The article discusses the following issues of the Brazilian cement sector: the Brazilian cement main types specification, cement quantities evolution produced in Brazil from 1987 to 1997, energy conservation in the cement production process with additives, energy economy cost estimates from the utilization of additives, and several technologies energy economy cost used in the industrial sector.

  2. Percutaneous Cement-Augmented Screws Fixation in the Fractures of the Aging Spine: Is It the Solution?

    Directory of Open Access Journals (Sweden)

    Sébastien Pesenti

    2014-01-01

    Full Text Available Introduction. Management of elderly patients with thoracolumbar fractures is still challenging due to frequent osteoporosis and risk of screws pull-out. The aim of this study was to evaluate results of a percutaneous-only procedure to treat these fragile patients using cement-augmented screws. Methods. 12 patients diagnosed with a thoracolumbar fracture associated with an important loss of bone stock were included in this prospective study. Surgical procedure included systematically a percutaneous osteosynthesis using cemented fenestrated screws. When necessary, additional anterior support was performed using a kyphoplasty procedure. Clinical and radiographic evaluations were performed using CT scan. Results. On the whole series, 15 fractures were diagnosed and 96 cemented screws were inserted. The difference between the pre- and postoperative vertebral kyphosis was statistically significant (12.9° versus 4.4°, P=0.0006. No extrapedicular screw was reported and one patient was diagnosed with a cement-related pulmonary embolism. During follow-up period, no infectious complications, implant failures, or pull-out screws were noticed. Discussion. Aging spine is becoming an increasing public health issue. Management of these patients requires specific attention due to the augmented risk of complications. Using percutaneous-only screws fixation with cemented screw provides satisfactory results. A rigorous technique is mandatory in order to achieve best outcomes.

  3. Mechanics of bone/PMMA composite structures: an in vitro study of human vertebrae.

    Science.gov (United States)

    Race, Amos; Mann, Kenneth A; Edidin, Avram A

    2007-01-01

    The goal of this study was to provide material property data for the cement/bone composite resulting from the introduction of PMMA bone cement into human vertebral bodies. A series of quasistatic tensile and compressive mechanical tests were conducted using cement/bone composite structures machined from cement-infiltrated vertebral bodies. Experiments were performed both at room temperature and at body temperature. We found that the modulus of the composite structures was lower than bulk cement (p<0.0001). For compression at 37( composite function)C: composite =2.3+/-0.5GPa, cement =3.1+/-0.2GPa; at 23( composite function)C: composite =3.0+/-0.3GPa, cement =3.4+/-0.2GPa. Specimens tested at room temperature were stiffer than those tested at body temperature (p=0.0004). Yield and ultimate strength factors for the composite were all diminished (55-87%) when compared to cement properties. In general, computational models have assumed that cement/bone composite had the same modulus as cement. The results of this study suggest that computational models of cement infiltrated vertebrae and cemented arthroplasties could be improved by specifying different material properties for cement and cement/bone composite. PMID:16797554

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