Abstracts Book - IMRC 2018

• SE2-O034
IN VITRO BIOACTIVITY OF A DIOPSIDE-TRICALCIUM PHOSPHATE
BIOCERAMIC SYNTHESIZED BY THE GLASS-CERAMIC METHOD
Jorge López Cuevas 1 , Claudia López Badillo 2 , Juan Méndez Nonell 3 , Carlos Alberto Gutiérrez
Chavarría 1
1 Centro de Investigación y de Estudios Avanzados del IPN - CINVESTAV, Ceramics Engineering,
Mexico. 2 Universidad Autónoma de Coahuila, Facultad de Ciencias Químicas, Mexico. 3 Centro
de Investigación en Materiales Avanzados, S.C., , Mexico.
A bioactive material induces the formation of apatite in contact with
physiological fluids. This phase is very similar to hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 ,
which is considered as a model for the mineral constituent of animal and human
bones. On the other hand, a resorbable material can be broken down and
assimilated by the human body. Diopside (CaO·MgO·2SiO 2 ) is a bioactive and
resorbable material, whose bending and compressive strengths are higher than
those of the human cortical bone, and Tricalcium Phosphate (3CaO·P 2 O 5 ) is a
resorbable material. These properties make both materials useful for the
fabrication of implants. In this work, a biomaterial based on the eutectic
composition of the Diopside -Tricalcium Phosphate binary system,
corresponding to 61 and 39 wt.% of these phases, respectively, was synthesized
and characterized. The material was synthesized by using the so-called “glassceramic”
or “vitroceramic” process, in which a parent glass with the desired
composition is first obtained by melting and quenching a suitable mixture of raw
materials, and then subjected to a crystallization heat treatment. A thermal
treatment comprising a single heating and cooling cycle was employed in this
work. The cooling rate, holding time and treatment temperature were varied.
Then, all materials were soaked in a simulated body fluid (SBF) for 7, 14 and 21
days, and characterized by X-ray diffraction (XRD), scanning electron microscopy
(SEM), Vickers microhardness and chemical analysis by ICP. The synthesized
materials developed an apatite surface layer in contact with the SBF. The most
bioactive material was the one crystallized at 800 ºC, in which the diopside and
tricalcium phosphate equilibrium phases were absent, and which had low
mechanical properties. The best mechanical properties were obtained for the
materials treated at 1000 ºC/ 7 h and at 1100 ºC for 2, 5 or 7 h. This was due to
a larger development of the diopside phase. Under the latter conditions, the
apatite surface layer achieved a Ca/P molar ratio very close to that of
stoichiometric hydroxyapatite. Finally, the mechanicals properties, the Ca/P