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J Mater Sci Mater Med. 2001 Jun;12(6):471-8. doi: 10.1023/a:1011203226053.

Hydroxyapatite implants with designed internal architecture.

Journal of materials science. Materials in medicine

T M Chu, J W Halloran, S J Hollister, S E Feinberg

Affiliations

  1. Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. [email protected]

PMID: 15348260 DOI: 10.1023/a:1011203226053

Abstract

Porous hydroxyapatite (HA) has been used as a bone graft material in the clinics for decades. Traditionally, the pores in these HAs are either obtained from the coralline exoskeletal patterns or from the embedded organic particles in the starting HA powder. Both processes offer very limited control on the pore structure. A new method for manufacturing porous HA with designed pore channels has been developed. This method is essentially a lost-mold technique with negative molds made with Stereolithography and a highly loaded curable HA suspension as the ceramic carrier. Implants with designed channels and connection patterns were first generated from a Computer-Aided-Design (CAD) software and Computer Tomography (CT) data. The negative images of the designs were used to build the molds on a stereolithography apparatus with epoxy resins. A 40 vol% HA suspension in propoxylated neopentyl glycol diacrylate (PNPGDA) and iso-bornyl acrylate (IBA) was formulated. HA suspension was cast into the epoxy molds and cured into solid at 85 degrees C. The molds and acrylate binders were removed by pyrolysis, followed by HA green body sintering. With this method, implants with six different channel designs were built successfully and the designed channels were reproduced in the sintered HA implants. The channels created in the sintered HA implants were between 366 microm and 968 microm in diameter with standard deviations of 50 microm or less. The porosity created by the channels were between 26% and 52%. The results show that HA implants with designed connection pattern and well controlled channel size can be built with the technique developed in this study.

Copyright 2001 Kluwer Academic Publishers

References

  1. J Biomed Mater Res. 1993 Jan;27(1):25-34 - PubMed
  2. J Biomed Mater Res. 1996 Dec;32(4):603-9 - PubMed
  3. Australas Phys Eng Sci Med. 1993 Jun;16(2):79-85 - PubMed
  4. Acta Orthop Scand. 1994 Jun;65(3):246-52 - PubMed
  5. Br J Plast Surg. 1994 Jan;47(1):60-4 - PubMed
  6. J Digit Imaging. 1990 Aug;3(3):200-3 - PubMed
  7. Biomaterials. 1986 Mar;7(2):137-43 - PubMed
  8. Biomaterials. 1990 Jul;11:86-7 - PubMed
  9. J Oral Maxillofac Surg. 1998 Nov;56(11):1297-301; discussion 1302 - PubMed
  10. Pediatr Radiol. 1992;22(6):458-60 - PubMed
  11. Plast Reconstr Surg. 1979 May;63(5):626-33 - PubMed
  12. Clin Orthop Relat Res. 1981 Jun;(157):259-78 - PubMed
  13. Clin Orthop Relat Res. 1984 Sep;(188):252-62 - PubMed
  14. J Oral Maxillofac Surg. 1989 Dec;47(12):1282-9 - PubMed
  15. J Biomed Mater Res. 1993 Jan;27(1):35-45 - PubMed
  16. Nature. 1974 Jan 25;247(5438):220-2 - PubMed
  17. Biomaterials. 1998 Jan-Feb;19(1-3):133-9 - PubMed
  18. J Biochem. 1997 Feb;121(2):317-24 - PubMed
  19. Matrix. 1992 Jun;12(3):202-12 - PubMed
  20. Biomaterials. 1995 Mar;16(5):409-15 - PubMed

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