An Octacalcium Phosphate Forming Cement

Published

April 16, 2010

Author(s)

Milenko Markovic, Laurence C. Chow

Abstract

The osteoconductive and possibly osteoinductive characteristics of OCP increased the interest in preparation of bone graft materials that contain OCP in its composition. Calcium phosphate cements (CPCs) were prepared using a mixture of α tricalcium phosphate (α TCP) and dicalcium phosphate anhydrous (DCPA), with α TCP/DCPA molar ratio of 1/1 and distilled water or 0.5 mol/L phosphate aqueous solution (pH = 6.1 ± 0.1 ) as the cement liquid. Hardening time was (30 ± 1) min for the CPC mixed with water and (5 ± 1) min for the CPC mixed with phosphate solution. Diametral tensile strength (DTS), porosity (P), and phase composition (powder x-ray diffraction) were determined after the hardened specimens had been immersed in a physiological-like solution (PLS) for 1 d, 3 d, and 7 d. In CPC specimens prepared with water, calcium hydroxyapatite (HA) was formed and DTS and P were (9.03 ± 0.48) MPa and (37.05 ± 0.20) vol % after 1 d, respectively, and (9.15 ± 0.45) MPa and (37.24 ± 0.63) vol % after 3 d, respectively. In CPC specimens prepared with phosphate solution OCP and HA were formed and DTS and P were (4.38 ± 0.49) MPa and (41.44 ± 1.25) vol % after 1 d, respectively, (4.38 ± 0.29) MPa and (42.52 ± 2.15) vol % after 3 d, respectively, and (4.30 ± 0.60) MPa and (41.38 ± 1.65) vol % after 7 d, respectively. For each group DTS and P did not change with PLS immersion time. DTS was significantly higher and P was significantly lower for CPCs prepared with water. HA formation slightly increased with immersion time from 40 mass % after 1d to 50 mass % after 3 d in CPCs prepared with water. OCP + HA formation increased with immersion time from 30 mass % after 1 d to 35 mass % after 3d and to 45 mass % after 7 d in CPCs prepared with 0.5 mol/L phosphate solution.

Citation

Journal of Research (NIST JRES) -

Volume

115

Issue

4

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

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Keywords

Octacalcium Phosphate, Calcium Phosphate Cement, Cement liquids, Hardening Time, Diametral Tensile Strength, Calcium Hydroxyapatite

Citation

Markovic, M. and Chow, L. (2010), An Octacalcium Phosphate Forming Cement, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=905159 (Accessed December 22, 2024)