Resumo (PT):
Abstract (EN):
In the present study, mechanical properties of porous glass reinforced hydroxyapatite
bioceramics were assessed by microhardness, bending and compression tests and fracture toughness determination. Porous discs were produced by a dry method using wax spheres as pore formers. Green bodies were sintered and the final microstructure of the composites consists of hydroxyapatite, alpha and beta tricalcium phosphate (α and β-Ca3
(PO4
)2
)due to the reaction between
the glassy phase and the hydroxyapatite matrix. The results of the mechanical tests showed that
the glassy phase yielded higher fracture toughness and bending strength when comparing with
literature data for single hydroxyapatite. There is a compromise between mechanical properties
and the porosity level for bioceramics: for example, according to Weibull statistics for composites
with 65% porosity the maximum bending stress level is 0.2 MPa for 100% survival probability
whereas this stress level increases to 2.5 MPa for composites with 40%. However, only the 65%
porosity composite samples seem to have the complete adequate morphology for bone ingrowth.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
5