Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-24T15:07:53.473Z Has data issue: false hasContentIssue false
  • English
  • Français

Biocompatible Ceramics for Implants Based on Calcium Phosphates

Published online by Cambridge University Press:  01 February 2011

Tatiana Safronova ,
Valery I. Putlayev ,
Alexander G. Veresov ,
Anton V. Kuznetsov ,
Mikhail A. Shekhirev  and
Kamila A. Agahi
Tatiana Safronova
Affiliation:
[email protected], MSU, Department of Chemistry, Moscow 119992 Leninskie Gory, 1, Moscow, N/A, Russian Federation
Valery I. Putlayev
Affiliation:
[email protected], MSU, Department of Chemistry, Leninskie Gory, 1/3, Moscow, 119992, Russian Federation
Alexander G. Veresov
Affiliation:
[email protected], MSU, Department of materials science, Leninskie Gory, 1, Moscow, 119992, Russian Federation
Anton V. Kuznetsov
Affiliation:
[email protected], MSU, Department of materials science, Leninskie Gory, 1, Moscow, 119992, Russian Federation
Mikhail A. Shekhirev
Affiliation:
[email protected], MSU, Department of materials science, Leninskie Gory, 1, Moscow, 119992, Russian Federation
Kamila A. Agahi
Affiliation:
[email protected], MSU, Institute of Mechanics, Leninskie Gory, 1, Moscow, 119992, Russian Federation
Get access

Abstract

Hydroxyapatite (HAp), tricalcium phosphate (TCP) and calcium pyrophosphate (CPP) are known to be among calcium phosphates used in clinical medicine due to their biocompatibility. HAp and other complex calcium phosphate salts are the end-products of the biological mineralization process. Calcium pyrophosphate Ca2P2O7 (β-CPP) is one of the intermediate products involved in this process. The biological response with respect to new bone formation is quite similar for CPP and HAp. Sintered CPP has better biological responses, and, thus, a great potential as a biodegradable bone substitute. The rate of biodegradation depends on: (i) material texture (porosity type and level), (ii) quality of biodegradation phase (phase composition, grain size, properties of grain boundaries). Several sources for CPP phase in ceramics can be assumed. CPP phase may come from frit (CaO-P2O5, Ca/P=0.2-0.75) used as a sintering additive. Ceramics can be fabricated from powder of CPP with Na4P2O7 as sintering additive, via interaction between H3PO4 or (NH4)2HPO4 and porous HAp at high temperature after soaking it in the former solutions. The aim of the present work was focused on fabrication of multiphase ceramics with enhanced resorptivity due to presence of CPP phase and investigation of processes leading to formation of the multiphase ceramics based on HAp and CPP originated from CaHPO4. Ceramic materials have been made from mixtures of powders of stoihiometric HAp (Ca/P=1.67) and monetite (CaHPO4, Ca/P=1). Powders of HAp and monetite were synthesized by means of wet chemical precipitation from aqueous solutions of Ca(NO3)2*4H2O and (NH4)2HPO4 at 60 °C and pH=9 for HAp and pH=4-5 for monetite. Component ratio HAp:monetite was varied from 0:100 to 100:0 % with a step of 20%. Powders of raw materials and the mixtures were tested by means of XRD, TG, DTG, SEM, dilatometry. Linear shrinkage, density and microstructure of samples of ceramic materials sintered at 900, 1000, 1100°C with isothermal holding during 6 hours were tested. Complicated consequence of phase transformations took place during heating the the mixtures from 20 to 1200 C. The CPP (Ca/P=1, converted from CaHPO4 at 400-500°C ) reacts with HAp (Ca/P=1.67) causing additional weight loss in the region of 600-1050°C due to solid state reaction leading to TCP (Ca/P=1.55) formation. Linear shrinkage of HAp at 1100°C after 6 hours was found to be about 21%; for Ca2P2O7 formed from monetite, and for the mixtures - less than 11%. Resulted ceramics with the phase composition of HAp, CPP and TCP, i.e. with a different content of degradable phase and different ratio of CPP/TCP, can be treated as a biocompatible bioactive material with a tunable rate and limit of biodegradation.

Keywords

biomaterialceramicchemical reaction
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 951: Symposium E – Nanofunctional Materials, Nanostructures and Novel Devices for Biological and Chemical Detection , 2006 , 0951-E12-31
Copyright
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Kanazava, T.. Inorganic phosphate materials. Elsevier Science Publishing B.V., Amsterdam 1989 Google Scholar
2. Knowles, J. C. Phosphate based glasses for biomedical applications //J.Mater.Chem., 2003 [13] 2395–2401 Google Scholar
3. Tanko, L. B., Felsenberg, D., Czerwinski, E., Burdeska, A., Jonkanski, I., Hughes, C. & Christiansen, C.. Oral weekly ibandronate prevents bone loss in postmenopausal women//Journal of Internal Medicine 2003; 254: 159–167 Google Scholar
4. Mattano, L. A. Jr Strategic approaches to osteoporosis in transplantation//Pediatr. Transplantation 2004: 8 (Suppl. 5): 51–55 Google Scholar
5. Sun, J.S., Tsuang, Y.H., Liao, C.J., Hang, Y.S., Lin, F.H.. The effect of sintered ß-dicalcium phosphate particle size on newborn wistar ratosteoblasts//Atifitial Organs, 23 [4] 331–338, 1999.Google Scholar
6. US Patent 4376168, A.Takami, et al. Phosphate of calcium ceramic. 1983.Google Scholar
7. Lin, F.N., Lin, C.C., Lu, C.M., Lui, H.C., J.S. Sun Mechanical properties histological evaluation of sintered beta- Ca2P2O7 with Na4P2O7*10H2O addition//Biomaterials 1995 [16], 793–802.Google Scholar
8. US Patent 4861733, E.W.White. Calcium Phosphate bone substitute materials. 1989.Google Scholar
9. Grover, Liam M., Gbureck, Uwe, Wright, Adrian J., Barralet, Jake E. J. Cement Formulations in the Calcium Phosphate H2O–H3PO4–H4P2O7 System// Am. Ceram. Soc., 88 [11] 3096–3103 (2005)Google Scholar
10. Bian, Jian-jiang, Kim, Dong-Wan, Hong, Kug Sun. Microwave dielectric properties of Ca2P2O7 // Journal of the European Ceramic Society 2003 [23] 2589–2592 Google Scholar
11. Grover, Liam M., Gbureck, Uwe, Wright, Adrian J., Barralet, Jake E. J. Cement Formulations in the Calcium Phosphate H2O–H3PO4–H4P2O7 System// Am. Ceram. Soc., 88 [11] 3096–3103 (2005)Google Scholar
12. Ryu, Hyun-Seung, Youn, Hyuk-Joon, Hong, Kung Sun, Chang, Bong-Sun, Lee, Choon-Ki, Chung, Sung-Soo. An improvement in sintering property of β-tricalcium phosphate by addition of calcium pyrophosphate//Biomaterials 23 (2002) 909–914.Google Scholar