



@article {2560,
	title = {Microstructural dependence of Young{\textquoteright}s and shear moduli of P                    2O
                    5 glass reinforced hydroxyapatite for biomedical applications
},
	journal = {BiomaterialsBiomaterials},
	volume = {21},
	year = {2000},
	note = {Cited By (since 1996): 32Export Date: 21 November 2012Source: ScopusCODEN: BIMADdoi: 10.1016/S0142-9612(99)00248-3PubMed ID: 10711972Language of Original Document: EnglishCorrespondence Address: Lopes, M.A.; INEB Inst. de Engenharia Biomedica, Laboratorio de Biomaterials, Rua do Campo Alegre 823, 4150 Porto, PortugalChemicals/CAS: Biocompatible Materials; Hydroxyapatites; PhosphatesReferences: Burstein, A., Wright, T.M., (1994) Fundamentals of Orthopaedic Biomechanics, , Lippincott: Williams \& Wilkins;Carter, D.R., Giori, N.J., Effect of mechanical stresses on tissue differentiation in the bony implant bed (1991) In the Bone-material Interface, pp. 367-379. , J.E. Davies. Toronto: University of Toronto Press; 
(1995) E - Advanced Technical Ceramics, (PART 2). , European prestandard, ref. no. ENV 843-2:; 
Schreiber, E., Anderson, O.L., Soga, N., (1989) Elastic Constant and Their Measurements, , New York: McGraw-Hill; 
Santos, J.D., Knowles, J.C., Reis, R.L., Monteiro, F.J., Hastings, G.W., Microstructural characterisation of glass reinforced hydroxyapatite composites (1994) Biomaterials, 15, pp. 5-10; 
Knowles, J.C., Talal, S., Santos, J.D., Sintering effects in a glass reinforced hydroxyapatite (1996) Biomaterials, 17, pp. 1437-1442; 
Knowles, J.C., Santos, J.D., Monteiro, F.J., Olsen, I., Flow cytometry for assessing biocompatibility (1998) J Biomed Mater Res, 41, pp. 649-656; 
Lopes, M.A., Knowles, J.C., Santos, J.D., Monteiro, F.J., Olsen, I., Biological evaluation of glass reinforced hydroxyapatite by flow cytometry (1998) Bioceramics, 10, pp. 575-578; 
Rice, R.W., Microstructure dependence of mechanical behaviour (1977) Treatise on Materials Science and Technology, 11, pp. 200-382. , MacCrone R.K. New York: Academic Press; 
Lopes, M.A., Santos, J.D., Monteiro, F.J., Knowles, J.C., Glass reinforced hydroxyapatite: A comprehensive study of the effect of glass composition on the crystallography of the composite (1998) J Biomed Mater Res, 39, pp. 244-251; 
Murtage, B., (1981) Advanced Linear Programming, , New York: McGraw-Hill; 
Ch{\'a}tal, V., (1990) Linear Programming, , New York: W. H. Freeman; 
Tampieri, A., Celotti, G., Szontagh, F., Landi, E., Sintering and characterisation of hydroxyapatite and tricalcium phosphates with control of their strength and phase porosity (1997) J Mater Sci, 8, pp. 29-37; 
Knowles, J.K., Development of hydroxyapatite with enhanced mechanical properties: Effect of high glass additions on mechanical properties and phase stability of sintered hydroxyapatite (1994) Br Ceram Trans, 93, pp. 100-103; 
Aoki, H., (1991) Science and Medical Applications of Hydroxyapatite, , Japanese Association of Apatite Science. Tokyo: Takayama Press System Center Co. Inc; 
Sax, M., Zografou, C., Telle, R., Kalawrytimos, G., Properties of sintered apatite ceramics (1995) Ceramic Processing Science and Technology, Ceramic Transactions, 51, pp. 701-705. , In: Hausner H, editor; 
Katz, J.L., Akers, A.S., Germiller, J.A., Obremski, S.M., Singh, S., The elastic properties of apatites and tricalcium phosphates-calcite mixtures (1989) Bioceramics, 1, pp. 86-91; 
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},
	month = {2000///},
	pages = {749 - 754},
	publisher = {Elsevier Science Ltd},
	abstract = {P                        2O
                        5 glass reinforced hydroxyapatite composite materials were prepared through a liquid-phase sintering process. Secondary phases, β- and α- tricalcium phosphate (β-TCP and α-TCP), were formed in the microstructure of the composites, due to the reaction between the liquid glassy phase and the hydroxyapatite matrix. The dynamic Young{\textquoteright}s modulus (E) and shear modulus (G) of these composites were determined using an impulse excitation method. By applying the Duckworth-Knudsen equation, the elastic property results were correlated with the relative proportion of β-TCP and α-TCP phases and with the porosity percentage present in the microstructure. Glass reinforced hydroxyapatite composites showed lower Young{\textquoteright}s and shear moduli than unmodified hydroxyapatite, mainly due to presence of β-TCP phase. The Duckworth-Knudsen model demonstrated an exponential dependence of E and G modulus with porosity and mathematical equations were derived for composite materials with porosity correction factors (b) of 4.04 and 4.11, respectively, indicating that porosity largely decreased both E and G moduli. (C) 2000 Elsevier Science Ltd.
                        2O
                        5 glass reinforced hydroxyapatite composite materials were prepared through a liquid-phase sintering process. Secondary phases, β- and α-tricalcium phosphates (β-TCP and α-TCP), were formed in the microstructure of the composites, due to the reaction between the liquid glassy phase and the hydroxyapatite matrix. The dynamic Young{\textquoteright}s modulus (E) and shear modulus (G) of these composites were determined using an impulse excitation method. By applying the Duckworth-Knudsen equation, the elastic property results were correlated with the relative proportion of β-TCP and α-TCP phases and with the porosity percentage present in the microstructure. Glass reinforced hydroxyapatite composites showed lower Young{\textquoteright}s and shear moduli than unmodified hydroxyapatite, mainly due to the presence of β-TCP phase. The Duckworth-Knudsen model demonstrated an exponential dependence of E and G modulus with porosity and mathematical equations were derived for composite materials with porosity correction factors (b) of 4.04 and 4.11, respectively, indicating that porosity largely decreased both E and G moduli.
},
	keywords = {article, Biocompatible Materials, Ceramic matrix composites, Chemical analysis, chemical composition, composite graft, Duckworth-Knudsen model, Elastic moduli, Elasticity, glass, hydroxyapatite, Hydroxyapatite glass composites, Hydroxyapatites, Implants (surgical), Mathematical models, Microstructure, Molecular Structure, Phosphate minerals, Phosphates, porosity, priority journal, Shear modulus, shear stress, young modulus, Young{\textquoteright}s modulus},
	isbn = {01429612 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0033975337\&partnerID=40\&md5=3822598d9be6e02a2a07e3465efe1ab6},
	author = {Lopes, M.A. and Silva, R.F. and Monteiro, F.J. and Santos, J.D.}
}
