ISSN:
1573-4838
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Technology
Notes:
Abstract Cement samples made of β-tricalcium phoshate (β-TCP), phosphoric acid (PA) and water mixtures were incubated in several aqueous solutions to determine their stability over time. The effects of the cement composition and the incubating temperature were investigated in more detail. The cement samples contained mostly dicalcium phosphate dihydrate (DCPD) and remnants of β-TCP crystals. Depending on the initial cement composition, a certain amount of dicalcium phosphate (DCP) crystals were formed. The larger the initial PA concentration, the larger the DCP amount. After setting, the cement composition was stable for at least 16 days up to 60 °C. Above that temperature, the DCPD crystals decomposed into DCP crystals. The latter reaction provoked a decrease of the pH of the incubation solution, phenomenon expected for a cement sample containing an excess of PA. As the cement samples contained an excess of β-TCP, it was postulated that β-TCP crystals became so covered by DCP or DCPD crystals during setting that the setting reaction was stopped prematurely. The latter phenomenon gave a good explanation for the low pH values measured in the incubation solutions. ©©2000 Kluwer Academic Publishers
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008927624493
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