Fabrication of Chelate-Setting Cement Using Silicon-Substituted Hydroxyapatite and its Property

Abstract:

We have developed novel hydroxyapatite (HAp) cement, “chelate-setting HAp cement” on the basis of chelate bonding of inositol hexaphosphate (IP6). In order to create the cement with enhanced bioactivity, we used a silicon-substituted hydroxyapatite (Si-HAp) as a starting material instead of pure HAp powder. The Si-HAp powders were prepared via an aqueous precipitation reaction and surface-modified with IP6 (IP6-Si-HAp). The Si-HAp were synthesized with desired Si contents (0, 0.4, 0.8, 1.6, and 2.4 mass%). Regardless of the amount of Si, the XRD patterns and FT-IR spectra of the powders were similar to each other. Additionally, chemical composition of Si-HAp powders were the almost same as the nominal one. The substitution of Si resulted in a decrease in the a-axis and increase in the c-axis of unit cell of HAp. While, the compressive strength of IP6-Si-HAp cements was higher than that of Si-HAp cements. These results suggest that surface-modification of any powders with IP6 is effective for enhancement of mechanical property. Comparison of mechanical property between HAp and Si-HAp cement specimens revealed that the substitution of lower levels of Si into0 HAp lattice did not greatly influence compressive strength. However, the substitution of high dose of Si (over 2.4 mass%) reduced the compressive strength. Therefore, to fabricate the chelate-setting cements with enhanced bioactivity, it is necessary to control the amount of Si.

• Periodical: Key Engineering Materials (Volumes 493-494)
• Pages: 370-374
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.493-494.370
• Online since: October 2011
• Authors: Y. Nakashima, Michiyo Honda, Toshiisa Konishi, Minori Mizumoto, Mamoru Aizawa
• Keywords: Cement, Hydroxyapatite (HAP), Inositol Phosphate, Silicon-Substituted Hydroxyapatite

References

[1] I. R. Gibson, J. Huang, S. M. Best and W. Bonfield, Enhanced in vitro cell activity and surface apatite layer formation on novel silicon-substituted hydroxyapatites, Bioceramics. 12, 191 (1999).

DOI: 10.1142/9789814291064_0046

[2] I. R. Gibson, S. M. Best and W. Bonfield, Chemical characterization of silicon-substituted hydroxyapatite, J. Biomed. Mater. Res 44. 422-428 (1999).

DOI: 10.1002/(sici)1097-4636(19990315)44:4<422::aid-jbm8>3.0.co;2-#

[3] M. Aizawa, K. Itatani, and I. Okada, Syntheses of calcium-deficient apatite fibres by a homogeneous precipitation method and their characterizations, Phosphorus Res. Bull. 20, 61 (2006).

DOI: 10.1016/j.jeurceramsoc.2005.07.007

[4] A. Yoshikawa, Y. Horiguchi, K. Oribe, and M. Aizawa, Mechanical property of apatite cement hardened by chealting-effect of inositol phosphate, Arch. BioCeram. Res. 6, 216-219 (2006).

[5] Y. Horiguchi, A. Yoshikawa, K. Oribe and M. Aizawa, Fabrication of chelate-setting hydroxyapatite cements from four kinds of commercially-available powder with various shape and crystallinity and their mechanical property, J. Ceram. Soc. Jpn. 116, 50-55 (2008).

DOI: 10.2109/jcersj2.116.50