Effect of Sintering Temperature on Mechanical Properties and Microstructure of Sheep-bone Derived Hydroxyapatite (SHA)

  • U. Karacayli
  • O. Gunduz
  • S. Salman
  • L. S. Ozyegin
  • S. Agathopoulos
  • F. N. Oktar
Conference paper
Part of the IFMBE Proceedings book series (IFMBE, volume 23)


Hydroxyapatite (HA) is currently one of the most attractive materials for human hard tissue implants because its close crystallographic resemblance to bones and teeth, conferring HA with excellent biocompatibility. Because of that fact as well as economic and time-saving reasons, we have stressed the need for safe production of HA-powders and ceramics from natural resources, such as animals’ bones and teeth, or hydrothermal transformation of shell’s aragonite.

Nevertheless, the applications of pure HA-ceramics are limited to non load-bearing implants, because of HA’s poor mechanical properties. Our research group has dedicated a lot of effort to achieve enhancement of mechanical strength and the fracture toughness of sintered HA-ceramics, mainly with HApowder of natural origin, by fabricating composite materials of HA doped with various types of biocompatible oxides.

This work aims to present that bulk ceramics of pure HA (i.e. with no incorporation of any reinforcing phase), derived from sintered HA—powder obtained from calcinated (at 850°C) bones of sheep (SHA), exhibit the best mechanical properties ever measured for sintered HA ceramics (pure and composites) using naturally (i.e. animal bone) derived HA. The characterization of the new HA-ceramics comprised measurements of density and mechanical properties, namely compressive strength and Vickers microhardness, along with microstructure observation with scanning electron microscopy (SEM). The best mechanical properties were achieved in the samples sintered between 1200°C–1300°C; the highest value of compression strength was achieved after sintering at 1300°C, 180.75 MPa. SEM observations in conjunction with density measurements confirmed the good sintering ability of the SHA-powders to highly condense bulk HA-ceramics.


Hydroxyapatite sheep derived hydroxyapatite mechanical properties 


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  1. 1.
    Oktar FN (2006) Hydroxyapatite-TiO2 composites. Mater Lett 60: 2207–2210.CrossRefGoogle Scholar
  2. 2.
    Gunduz O, Daglilar S, Salman S et al (2008) Effect of Yttria-doping on Mechanical Properties of Bovine Hydroxyapatite (BHA). J Composite Mater 42: 1281–1287.CrossRefGoogle Scholar
  3. 3.
    Gunduz O, Erkan EM, Daglilar S et al. (2008) Composites of bovine hydroxyapatite (BHA) and ZnO. J Mater Sci 43:2536–2540.CrossRefGoogle Scholar
  4. 4.
    Rocha JHG, Lemos AF, Agathopoulos S et al. (2005). Scaffolds for bone restoration from cuttlefish. Bone 37: 850–857.CrossRefGoogle Scholar
  5. 5.
    Goller G, Oktar FN (2002) Sintering effects on mechanical properties of biologically derived dentine hydroxyapatite. Mater Lett 56: 142–147.Google Scholar
  6. 6.
    Oktar FN, Goller G (2002) Sintering effects on mechanical properties of glass-reinforced hydroxyapatite composites. Ceram Int 28: 617–621.CrossRefGoogle Scholar
  7. 7.
    Nath S, Sinha N, Basu B (2008) Microstructure, mechanical and tribological properties of microwave sintered calcia-doped zirconia for biomedical applications. Ceram Int 34: 1509–1520.CrossRefGoogle Scholar
  8. 8.
    Goller G, Oktar FN, Ozyegin LS et al. (2004) Plasma-sprayed human bone-derived hydroxyapatite coatings: effective and reliable. Mater Lett 58: 2599–2604.CrossRefGoogle Scholar
  9. 9.
    Kurkcu M, Benlidayı ME, Ozsoy S, et al. (2008) Histomorphometric evaluation of implants coated with enamel or dentine derived fluoride-substituted apatite. J Mater Sci: Mater in Med 19: 59–65.CrossRefGoogle Scholar
  10. 10.
    Carvalho AL, Faria PEP, Marcio Grisi MFM et al. (2007) Effects of granule size on the osteoconductývýty of bovine and synthetic hydroxyapatite: A histologic and histometric study in dogs. J Oral Implant 33: 267–276.CrossRefGoogle Scholar
  11. 11.
    Ozyegin LS, Oktar FN, Goller G et al. (2004) Plasma-sprayed bovine hydroxyapatite coatings. Mater Lett 58: 2605–2609.CrossRefGoogle Scholar
  12. 13. Geographical Distribution of Countries that reported BSE Confirmed Cases since 1989. Last update: 04 January 2007Google Scholar
  13. 14. Final Report on the assessment of the Geographical BSE-risk of Turkey 27 June 2002Google Scholar
  14. 15.
    Opinion of the Scientific Steering Committee on the Geographical Risk Of Bovine Spongiform Encephalopathy (GBR) in Turkey Adopted by the SSC on 27 June 2002Google Scholar
  15. 16.
    Jan J, Vrecl M, A. Pogacnik A, Gaspersic D (2001) Bioconcentration of lipophilic organochlorines in ovine dentine. Arch Oral Bio 46: 1111–1116.CrossRefGoogle Scholar
  16. 17.
    Jan J, Milka V, Azra P et al. (2006) Distribution of organochlorine pollutants in ovine dental tissues and bone. Environ Toxic Pharma 21: 103–107.CrossRefGoogle Scholar
  17. 18.
    Bellof G, Most E, Pallauf J (2006) Concentration of Ca, P, Mg, Na and K in muscle, fat and bone tissue of lambs of the breed German Merino Landsheep in the course of the growing period. J Animal Physio Animal Nut 90: 385–393.CrossRefGoogle Scholar
  18. 19.
    Hillier ML, Bell LS (2007) Differentiating Human Bone from Animal Bone: A Review of Histological Methods. J Forensic Sci 52: 69–72CrossRefGoogle Scholar
  19. 20.
    Oktar FN, Kesenci K, Piskin E (1999) Characterization of processed tooth hydroxyapatite for potential biomedical implant applications. Artif Cell Blood Subs Immob Biotech 27: 367–379.Google Scholar
  20. 21.
    Goller G, Oktar FN, Agathopoulos S et al. (2006) Effect of sintering temperature on mechanical and microstructural properties of bovine hydroxyapatite (BHA). J Sol-Gel Sci Techn 37: 111–115.CrossRefGoogle Scholar
  21. 22.
    S. Goren, Gokbayrak H, S. Altintas (2004) Key Eng Mater 264–268: 1949–1952CrossRefGoogle Scholar
  22. 23.
    H. Gokbayrak, Production of hydroxyapatite ceramics, M.S. Thesis, Bogazici University, 1996.Google Scholar
  23. 24.
    Salman S, Oktar FN, Gunduz O et al. (2007) Sintering Effect on Mechanical Properties of Composites Made of Bovine Hydroxyapatite (BHA) and Commercial Inert Glass (CIG). Key Eng Mater 330–332: 189–192.CrossRefGoogle Scholar

Copyright information

© International Federation of Medical and Biological Engineering 2009

Authors and Affiliations

  • U. Karacayli
    • 1
  • O. Gunduz
    • 2
  • S. Salman
    • 2
  • L. S. Ozyegin
    • 3
  • S. Agathopoulos
    • 4
  • F. N. Oktar
    • 5
    • 6
  1. 1.Oral Surgery DepartmentGATAAnkaraTurkey
  2. 2.Metal Education DepartmentMarmara UniversityIstanbulTurkey
  3. 3.Dental Technology DepartmentMarmara UniversityIstanbulTurkey
  4. 4.Material Science and Engineering DepartmentIonnina UniversityIonninaGreece
  5. 5.Radiology DepartmentMarmara UniversityIstanbulTurkey
  6. 6.Industrial Engineering DepartmentMarmara UniversityIstanbulTurkey

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