The thermal stability of hydroxyapatite in biphasic calcium phosphate ceramics

Nilen, R. W. N.; Richter, P. W.
April 2008
Journal of Materials Science: Materials in Medicine;Apr2008, Vol. 19 Issue 4, p1693
Academic Journal
Biphasic calcium phosphate ceramics (BCP) comprising a mix of non-resorbable hydroxyapatite (HA) and resorbable β-tricalcium phosphate (β-TCP) are particularly suitable materials for synthetic bone substitute applications. In this study, HA synthesised by solid state reaction was mechanically mixed with β-TCP, then sintered to form a suite of BCP materials with a wide range of HA/β-TCP phase content ratios. The influence of sintering temperature and composition on the HA thermal stability was quantified by X-ray diffraction (XRD). The pre-sinter β-TCP content was found to strongly affect the post-sinter HA/β-TCP ratio by promoting the thermal decomposition of HA to β-TCP, even at sintering temperatures as low as 850 °C. For BCP material with pre-sinter HA/β-TCP = 40/60 wt%, approximately 80% of the HA decomposed to β-TCP during sintering at 1000 °C. Furthermore, the HA content appeared to influence the reverse transformation of α-TCP to β-TCP expected upon gradual cooling from sintering temperatures greater than 1125 °C. Because the HA/β-TCP ratio dominantly determines the rate and extent of BCP resorption in vivo, the possible thermal decomposition of HA during BCP synthesis must be considered, particularly if high temperature treatments are involved.


Related Articles

  • New ceramic technology contributes to advances in medical implants. Mastrogiacomo, John // Healthcare Purchasing News;Mar2006, Vol. 30 Issue 3, p76 

    The article discusses the impact of ceramic material and processing developments on medical implant applications. Advances in the use of ceramics for artificial joints are addressed. The role of ceramic technology in the evolution of implantable electronic devices is described. The application...

  • Hydration mechanism of a novel PCCP + DCPA cement system. Xiupeng Wang; Jiandong Ye; Yingjun Wang // Journal of Materials Science: Materials in Medicine;Feb2008, Vol. 19 Issue 2, p813 

    A novel partially crystallized calcium phosphate (PCCP) + dicalcium phosphate anhydrous (DCPA) system bone cement was introduced and the mechanism of the hydration was studied by means of solubility product constant ( K sp), XRD, pH value, and BET. Results showed that DCPA was more soluble than...

  • Nanobumps enhance implants.  // R&D Magazine;Jan2004, Vol. 46 Issue 1, p46 

    Reports on a research conducted by biomedical engineers at Purdue University in West Lafayette, Indiana which demonstrated that bone cells attached better to metals with rougher surfaces, potentially leading to more natural, longer lasting implants. Estimated increase on hip replacement cases...

  • An open-pored gelatin/hydroxyapatite composite as a potential bone substitute. Hillig, William B.; Choi, Y.; Murtha, S.; Natravali, N.; Ajayan, P. // Journal of Materials Science: Materials in Medicine;Jan2008, Vol. 19 Issue 1, p11 

    Gelatin matrix composites reinforced with fine hydroxyapatite (HA) dispersants were investigated in an exploratory study for their suitability as surgical implants. The criteria for the candidate implant material were that it: (1) be benign, (2) have useful mechanical properties under quasi-in...

  • Effect of filler surface morphology on the impact behaviour of hydroxyapatite reinforced high density polyethylene composites. Zhang, Y.; Tanner, K. // Journal of Materials Science: Materials in Medicine;Feb2008, Vol. 19 Issue 2, p761 

    Instrumented falling weight impact tests have been carried out to characterize the impact behaviour of hydroxyapatite reinforced high-density polyethylene composite (HA-HDPE) in order to use this biomaterial in skull implants. The effects of HA filler surface morphology and volume fraction on...

  • Effect of molding pressure on fabrication of low-crystalline calcite block. Xin Lin; Matsuya, Shigeki; Nakagawa, Masaharu; Terada, Yoshihiro; Ishikawa, Kunio // Journal of Materials Science: Materials in Medicine;Feb2008, Vol. 19 Issue 2, p479 

    We have reported that low-crystalline porous calcite block, which is useful as a bone substitute or a source material to prepare apatite-type bone fillers could be fabricated by exposing calcium hydroxide compact to carbon dioxide gas saturated with water vapor. In the present study, we...

  • Green chemical synthesis of calcium phosphate bioceramics. Dorozhkin, S. V. // Journal of Applied Biomaterials & Biomechanics;May2008, Vol. 6 Issue 2, p104 

    A standard preparation technique of the graft relevant calcium phosphates (which includes the dissolution of watersoluble compounds containing calcium cations and phosphate anions, the slow addition of one solution into another under alkaline pH, followed by aging, suspension separation, washing...

  • Calcium Phosphate Materials for Bone Repair Application. Li, Xiaoming; Huang, Jin; Fan, Yubo // Recent Patents on Biomedical Engineering;Aug2011, Vol. 4 Issue 2, p68 

    Calcium phosphates, with a composition and structure similar to the mineral phase of bone, have been recognized as satisfactory materials for bone repair because of their excellent biocompatibility, osteoconductive, and bioactivity. In this paper, the recent related patents are reviewed,...

  • In vivo behaviour of two different biphasic ceramic implanted in mandibular bone of dogs. Fariña, Natalia M.; Guzón, Fernando M.; Peña, Mónica L.; Cantalapiedra, Antonio G. // Journal of Materials Science: Materials in Medicine;Apr2008, Vol. 19 Issue 4, p1565 

    Alloplastic calcium phosphate bone substitutes such as hydroxyapatite (HA) and tricalcium phosphate (TCP) have been studied extensively due to their composition closely resembling the inorganic phase of bone tissue. On the same way, by manipulating the HA/TCP ratio it may be possible to change...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics