Scaffolds de óxido de titânio e biosilicato para aplicações médicas e odontológicas obtidos com o uso de partículas orgânicas
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Data
2015-01-30Autor
Fernandes, Mérilin Cristina dos Santos
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Scaffolds are an alternative to natural grafts to help bone regeneration in
large bone defects. Regardless of the material chosen for its manufacture,
scaffold should have a suitable dimensional microenvironment to promote
osteogenesis and an appropriate mechanical stability for the defect site.
Titanium dioxide (TiO2) is a highly biocompatible ceramic with good
osteoconductive properties and high reliability mechanical; biosilicate has
excellent bioactivity level. Thus, in order to fabricate scaffolds allying positive
mechanical strength and bioactivity characteristics necessary to a good product,
biosilicate was pioneered combined with TiO2. Among the techniques available
for scaffolds production, the sacrificial template method, in which porosity is
generated by thermal elimination of organic materials added to the ceramic
matrix, has a low cost, simplicity and versatility. Different sacrificial agents were
tested and the presentation of sawdust as a promising material in scaffolds
manufacture proved to be innovative and satisfactory. Microstructural analyzes
showed that controlled addition of wood sawdust amounts generated a
homogeneous and highly interconnected pore structure with 63% apparent
porosity and an average pore size higher than 200 μm. Bioactivity tests in SBF
showed that after 4 days of immersion has already observed starting
precipitation of hydroxycarbonate apatite in products with biosilicate, and after
12 days of immersion the scaffold was fully covered by this mineral. Mechanical
tests allowed evaluating the scaffolds behavior when they are requested by
tensile efforts, and revealed for samples with maximum porosity obtained,
higher values of strength for samples containing biosilicate. The produced
scaffolds had success in the pore structure obtained by sacrificial template
method being biosilicato addition guaranteed improvements in bioactivity and
mechanical strength.