64 - Ceramic Composites from Bovine Hydroxyapatite, ZrO2@SiO2, and Hydroxyapatite + 15%ZrO2@SiO2

Abstract

This study aimed to synthetize and evaluate the biaxial flexural strength of dense polycrystalline experimental composites from bovine hydroxyapatite (HA); ZrO 2 @SiO 2 coreshell; and HA + 15%ZrO 2 @SiO 2 . HA was extracted from solid bovine bone residues and broken to submicrometric powder. ZrO 2 coreshell covered by SiO 2 was synthetized through Stober sol-gel method. Disc-shaped specimens (12 ×1.2 mm) were synthesized at 1300 C (HA), 1340 C (ZrO 2 @SiO 2 ), and 1300 C (HA + 15%ZrO 2 @SiO 2 ). The sintering temperatures followed the maximum temperature indicated for each material, according to the literature. Next, the specimens were submitted to biaxial flexural strength test. The results were analyzed regarding normality by Shapiro Wilk test. Comparisons were made by Kruskall-Wallis test (α = 0.05) followed by Tukey test. DRX analysis demonstrated the characteristic peaks of ZrO 2 and HA in HA +15%ZrO 2 @SiO 2 . It was also possible to observe HA crystallinity decreasing with the addition of the coreshell. ZrO 2 @SiO 2 biaxial flexural strength (140.2 16.05 MPa) was significantly greater (p<.001) than HA (99.2 8.66 MPa), and HA + 15%ZrO 2 @SiO 2 (107.5 5.44 MPa). HA and HA + 15%ZrO 2 @SiO 2 showed no statistically differences. ZrO 2 @SiO 2 sintering was a promising alternative to make crystalline materials and HA-ZrO 2 @SiO 2 composite can be a promising biomaterial, after the search for adjustments in the sintering process.