Displaying publications 61 - 79 of 79 in total

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  1. Khadijah K, Mashita M, Saidu MF, Fazilah F, Khalid KA
    Med J Malaysia, 2004 May;59 Suppl B:123-4.
    PMID: 15468849
    This study is to qualitatively evaluate a locally produced hydroxyapatite (HA), made by AMREC-SIRIM in an experimental animal bone defect using New Zealand White (NZW) rabbits. HA cylindrical blocks measuring 2.5 mm (D) x 1.0 mm (H) were implanted in the rabbits' left tibia. The tibias were harvested within one to three weeks post-implantation. The implantion site was cut into thin undecalcified sections of about 30 microm to 60 microm and stained with Toluidine Blue and Goldner's Masson Trichrome. Microscopic examinations using standard light microscopy of these slides were performed.
    Matched MeSH terms: Bone Substitutes*
  2. Najafpour HD, Suzina AH, Nizam A, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:121-2.
    PMID: 15468848
    There was a significant increased in Absolute Contact Length measurements of endosteal bone growth along the Nickel-Titanium (NiTi) implant coated with the natural coral powder and Hydroxyapatite (HA) compared to the non-calcium coated implants. This study demonstrated that coated implants seemed to show earlier and higher osseointergration phenomena compared to non coated ones. Furthermore, there was significantly greater bone-to-implant contact at the apical 1/3rd of the coated implants.
    Matched MeSH terms: Bone Substitutes*
  3. Rosdan S, Al-Salihi KA, Suzina AH, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:111-2.
    PMID: 15468843
    The main objective of the study was to determine the biodegradability, resorption and osteoconductivity potency of coral implant. Coral blocks (CORAGRAF) were prepared from sea coral Porites species. The blocks were implanted in the right mandible of rabbit model. Implants were harvested at 2 and 4 weeks intervals and subjected for light and scanning electron microscopy. Dense hydroxyapatite (DHA) was implanted in the left mandible as a control. The results of this study demonstrated that CORAGRAF is a good implant material that can accelerates bone healing and be resorbed in an acceptable time. The mechanisms of the resorption seemed to be the same (crumbling process), a first step where the edge of the coral become powdery then a second step which could be phagocytosis and dissolution in extracellular fluid.
    Matched MeSH terms: Bone Substitutes*
  4. Shaari R, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:109-10.
    PMID: 15468842
    The present in vitro evaluation indicated that the value added hydroxyapatite (HA) was more toxic than pure HA but the toxicity of value added HA was slight compared to the positive control. In this testing, the conclusion can be made that value added HA is less biocompatible than commercialized pure HA. This toxicity may be caused by both the particle size and degradation (leaching). Further studies should be carried out to determine whether there is particle size effect or leaching effect when using powder as compared to the block materials. The in vivo evaluation should be done to assess the reaction to this value added HA as compared to the pure HA.
    Matched MeSH terms: Bone Substitutes/toxicity*
  5. Suzina AH, Azlina A, Shamsuria O, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:105-6.
    PMID: 15468840
    Mutagenicity of CORAGRAF (natural coral) and REKAGRAF (hydroxyapatite) was tested in Ames test with and without an external metabolic activation system (S9). The test revealed no mutagenic activity of both locally produced osseous substitutes.
    Matched MeSH terms: Bone Substitutes/toxicity*
  6. Hollister SJ, Lin CY, Lin CY, Schek RD, Taboas JM, Flanagan CL, et al.
    Med J Malaysia, 2004 May;59 Suppl B:131-2.
    PMID: 15468853
    Matched MeSH terms: Bone Substitutes*
  7. Kokubo T
    Med J Malaysia, 2004 May;59 Suppl B:91-2.
    PMID: 15468833
    Metallic materials implanted into bone defects are generally encapsulated by a fibrous tissue. Some metallic materials such as titanium and tantalum, however, have been revealed to bond to the living bone without forming the fibrous tissue, when they were subjected to NaOH solution and heat treatments. Thus treated metals form bone tissue around them even in muscle, when they take a porous form. This kind of osteoconductive and osteoinductive properties are attributed to sodium titanate or tantalate layer on their surfaces formed by the NaOH and heat treatments. These layers induce the deposition of bonelike apatite on the surface of the metals in the living body. This kind of bioactive metals are useful as bone substitutes even highly loaded portions, such as hip joint, spine and tooth root.
    Matched MeSH terms: Bone Substitutes/chemical synthesis*
  8. Idris B, Rusnah M, Reusmaazran YM, Rohaida CH
    Med J Malaysia, 2004 May;59 Suppl B:67-8.
    PMID: 15468822
    Matched MeSH terms: Bone Substitutes/analysis; Bone Substitutes/chemical synthesis*
  9. Ginebra MP, Aparicio C, Engel E, Navarro M, Javier Gil F, Planell JA
    Med J Malaysia, 2004 May;59 Suppl B:65-6.
    PMID: 15468821
    Matched MeSH terms: Bone Substitutes/pharmacology*
  10. Azran YM, Idris B, Rusnah M, Rohaida CH
    Med J Malaysia, 2004 May;59 Suppl B:79-80.
    PMID: 15468828
    The paper presents the effect of sintering temperature on the physical properties of porous hydroxyapatite (HAp In this study, the HAp was prepared using polymeric sponge techniques with different binder concentrations. The sintering process was carried out in air for temperature ranging from 1200 degrees C to 1600 degrees C. Different physical properties namely density and porosity were observed at different sintering temperatures. The HAp prepared with higher PVP binder showed a slightly decreased in apparent density with increasing sintering temperature, while those HAp prepared with lower PVP showed a slightly increase in apparent density with increasing sintering temperature. The total porosity was found to be approximately constant in the whole sintering temperature range. However, closed porosity decreases with increasing sintering temperature for HAp prepared by lower binder concentration. On the other hand, the HAp prepared by higher binder concentrations showed increasing closed porosity with increasing sintering temperature. Other features such as the influence of sintering temperatures on grain and strut would also be presented in this paper.
    Matched MeSH terms: Bone Substitutes/analysis*; Bone Substitutes/chemical synthesis
  11. Hee SL, Nik Intan NI, Fazan F
    Med J Malaysia, 2004 May;59 Suppl B:77-8.
    PMID: 15468827
    There is a great demand of Hydroxyapatite (HA) material in Orthopaedics and Dental applications due to its similarity to human bone. However, the lack of availability and due to high import cost of this material in Malaysia, research in producing synthetic HA locally is therefore timely. The use of local resources as the raw materials for the production of HA is also desirable in reducing the overall cost of HA. In this study, two HA materials were synthesised from different starting precursors, i.e. commercial pure Ca(OH)2 (HAS) and Ca(OH)2 directly from a local natural limestone deposit (HAL). Whereas a commercially available HA "Captal 60" (HAC) was used as reference. The synthesised powders obtained were fired at 1000 degrees C and at 1250 degrees C. Characterisation evaluations on bulk properties were carried out using XRD, SEM-EDX, ICP and FTIR. The results indicate that both HAS and HAL are comparable to HAC even at 1000 degrees C. Thus, the local natural limestone can be used to form HA. However, the overall appearance of these materials are quite different (HAC - blue, HAS - greenish and HAL - light green). The reasons for this and the subsequent mechanical and bioactive effects of these materials are currently being investigated.
    Matched MeSH terms: Bone Substitutes/analysis; Bone Substitutes/chemical synthesis*
  12. Fazan F, Shahida KB
    Med J Malaysia, 2004 May;59 Suppl B:69-70.
    PMID: 15468823
    The paper presents a method of producing synthetic Hydroxyapatite (HA) Ca10(PO4)6(OH)2 and other apatites for biological use by solid-state reaction. The solid-state reaction involves mix-grinding dry powders of beta-tricalcium phosphate powder (TCP) and either calcium hydroxide (Ca(OH)2) or calcium carbonate (CaCO3) or combination thereof, from pure commercial chemicals or derived from natural limestone or from seashells, of total calcium/phosphorus molar ratio between 1.5 to 2.0, to particle size of less than 10 microns, and firing the resultant powder to temperature between 600 degrees C - 1250 degrees C in atmosphere or in controlled atmospheric condition. The resultant apatites formed were characterised using XRD, SEM-EDX and FTIR. The presented reaction process was found to be much simpler compared to conventional methods of producing synthetic apatites since it involves only dry mix-grinding of the reactants before firing at high temperatures based on the required levels of purity. It can also produce synthetic apatites with good reproducibility in a shorter time. Thus the presented method has a great industrial value.
    Matched MeSH terms: Bone Substitutes/analysis; Bone Substitutes/chemical synthesis*
  13. Saidu MF, Mashita M, Khadijah K, Fazan F, Khalid KA
    Med J Malaysia, 2004 May;59 Suppl B:85-6.
    PMID: 15468831
    Hydroxyapatite is a calcium phosphate bioceramic that has been shown by many authors to be biocompatible with bioactive properties. It is widely accepted as the best synthetic material available for surgical use as a bone graft substitute. HA granules produced by AMREC-SIRIM from local materials underwent 5 types of sterilisation techniques with different ageing periods. Samples were tested for chemical and phase composition and microbial contamination before and after being sterilised. From the microbiological tests done, none of the unsterilised positive control yielded a positive culture. Results from X-Ray diffraction studies found that all the sterilisation techniques did not chemically degrade or structurally change the HA granules significantly.
    Matched MeSH terms: Bone Substitutes/analysis*
  14. Rusnah M, Andanastuti M, Idris B
    Med J Malaysia, 2004 May;59 Suppl B:83-4.
    PMID: 15468830
    The paper discusses the influence of sintering temperature on the microstructure and strength of hydroxyapatite ceramics prepared using the extrusion process. The average pore diameters observed were in the range of approximately 150mm to 300mm whereas the compaction strength was found to be around 120-160 MPa.
    Matched MeSH terms: Bone Substitutes/analysis*; Bone Substitutes/chemical synthesis
  15. Doreya MI, Mona EW, Afaf ES, Hanan HB
    Med J Malaysia, 2004 May;59 Suppl B:21-2.
    PMID: 15468799
    The standard bioglass composition GS45 as well as with excess silica GS50 or with the addition of 5% titanium oxide GS45+Ti5, were prepared by the polymeric route. The different glass components were added to the formed polymer. Firing at 700 degrees C gave an amorphous product with microporous texture that readily crystallizes out at 900 degrees C. The prepared materials were highly porous with two modes of pore system micro-pores and macro-pores with a size ranging between 100 microm to 0.006 microm and a porosity reaching 73%. The measured bulk density was between 0.36 to 1.1g/cm3. The fired material preserved the former structure of the polymer precursor. Biocompatibility was verified in vitro and vivo. IR of the specimens previously immersed in SBF revealed the formation of apatite like layer. While the histology sections of implants in rate femurs showed new bone tissue or bone trabeculae after 21 days.
    Matched MeSH terms: Bone Substitutes/chemical synthesis*
  16. Ataollahi Oshkour A, Pramanik S, Shirazi SF, Mehrali M, Yau YH, Abu Osman NA
    ScientificWorldJournal, 2014;2014:616804.
    PMID: 25538954 DOI: 10.1155/2014/616804
    This study investigated the impact of calcium silicate (CS) content on composition, compressive mechanical properties, and hardness of CS cermets with Ti-55Ni and Ti-6Al-4V alloys sintered at 1200°C. The powder metallurgy route was exploited to prepare the cermets. New phases of materials of Ni16Ti6Si7, CaTiO3, and Ni31Si12 appeared in cermet of Ti-55Ni with CS and in cermet of Ti-6Al-4V with CS, the new phases Ti5Si3, Ti2O, and CaTiO3, which were emerged during sintering at different CS content (wt%). The minimum shrinkage and density were observed in both groups of cermets for the 50 and 100 wt% CS content, respectively. The cermets with 40 wt% of CS had minimum compressive Young's modulus. The minimum of compressive strength and strain percentage at maximum load were revealed in cermets with 50 and 40 wt% of CS with Ti-55Ni and Ti-6Al-4V cermets, respectively. The cermets with 80 and 90 wt% of CS showed more plasticity than the pure CS. It concluded that the composition and mechanical properties of sintered cermets of Ti-55Ni and Ti-6Al-4V with CS significantly depend on the CS content in raw cermet materials. Thus, the different mechanical properties of the cermets can be used as potential materials for different hard tissues replacements.
    Matched MeSH terms: Bone Substitutes/chemistry*
  17. Bajuri MY, Selvanathan N, Dzeidee Schaff FN, Abdul Suki MH, Ng AMH
    Tissue Eng Regen Med, 2021 06;18(3):377-385.
    PMID: 34043210 DOI: 10.1007/s13770-021-00343-2
    BACKGROUND: Managing massive bone defects, a great challenge to orthopaedics reconstructive surgery. The problem arise is the supply of suitable bone is limited with many complications. Tissue-engineered hydroxyapatite bone (TEHB) scaffold impregnated with osteoprogenitor cells developed as an alternative to promote bone regeneration.

    METHODS: This animal protocol has been approved by Universiti Kebangsaan Malaysia Animal Ethical Committee. The TEHB scaffold prepared from hydroxyapatite using gel casting method. A total of six adolescent female sheep were chosen for this study. Later, all the sheep were euthanized in a proper manner and the bone harvested for biomechanical study. Bone marrow was collected from iliac crest of the sheep and bone marrow stem cells (BMSCs) isolated and cultured. BMSCs then cultured in osteogenic medium for osteoprogenitor cells development and the plasma collected was seeded with osteoprogenitor cells mixed with calcium chloride. Bone defect of 3 cm length of tibia bone created from each sheep leg and implanted with autologous and TEHB scaffold in 2 different groups of sheep. Wound site was monitored weekly until the wound completely healed and conventional X-ray performed at week 1 and 24. Shear test was conducted to determine the shear force on the autologous bone and TEHB scaffold after implantation for 24 weeks.

    RESULTS: All of the sheep survived without any complications during the study period and radiograph showed new bone formation. Later, the bone harvested was for biomechanical study. The highest shear force for the autologous group was 13 MPa and the lowest was 5 MPa while for the scaffold group, the highest was 10 MPa and the lowest was 3 MPa. Although, proximal and distal interface of autologous bone graft shows higher shear strength compared to the TEHB scaffold but there is no significant difference in both groups, p value > 0.05. Histologically in both proximal and distal interface in both arms shows bone healing and woven bone formation.

    CONCLUSION: TEHB scaffold impregnated with osteoprogenitor cells has the potential to be developed as a bone substitute in view of its strength and capability to promote bone regeneration.

    Matched MeSH terms: Bone Substitutes*
  18. Zakaria SM, Sharif Zein SH, Othman MR, Yang F, Jansen JA
    Tissue Eng Part B Rev, 2013 Oct;19(5):431-41.
    PMID: 23557483 DOI: 10.1089/ten.TEB.2012.0624
    Hydroxyapatite is a biocompatible material that is extensively used in the replacement and regeneration of bone material. In nature, nanostructured hydroxyapatite is the main component present in hard body tissues. Hence, the state of the art in nanotechnology can be exploited to synthesize nanophase hydroxyapatite that has similar properties with natural hydroxyapatite. Sustainable methods to mass-produce synthetic hydroxyapatite nanoparticles are being developed to meet the increasing demand for these materials and to further develop the progress made in hard tissue regeneration, especially for orthopedic and dental applications. This article reviews the current developments in nanophase hydroxyapatite through various manufacturing techniques and modifications.
    Matched MeSH terms: Bone Substitutes/chemistry*
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