Estudo da influência de fluoreto de cálcio no composto hidroxiapatita/alumina

Abstract

Hydroxyapatite has great value in the clinical field, because it has osteoconductive property and chemical resemblance to the bones, but their applications are limited due to their mechanical properties are restricted. Thus, their use in form of the compound with alumina can increase such mechanical properties while maintaining bioactive characteristics at the same time, but at temperatures above 1000°C, the hydroxyapatite degrades in the presence of alumina. Additives such as calcium fluoride were used to inhibit such degradation, favoring the formation of fluorapatite, in addition to higher densification temperatures, improving its mechanical properties. This work was based on hydroxyapatite synthesized by acid and basic routes, using together fractions of alumina mass, with addition of calcium fluoride. With powders thoroughly mixed, the samples were sintered at 1450ºC. The following mechanical tests were performed: hardness, diametral compressive strength and flexural strength, as well as X-ray diffraction and infrared spectroscopy. The results showed that the mechanical properties of hydroxyapatite together with alumina did not rise even in the presence of calcium fluoride. Although the specimens contained calcium fluoride total degradation of the phase hydroxyapatite, the sample can not be considered a composite, requiring further work in this area.