Bovine hydroxyapatite/3Y-TZP bioceramic: Aligning 3Y-TZP content with sintering parameters

Area of Science:

• Biomaterials Science
• Materials Engineering
• Ceramics

Background:

• Hydroxyapatite (HA) is a key biomaterial for bone regeneration.
• Incorporating 3% Yttria-stabilized Tetragonal Zirconia (3Y-TZP) can enhance HA's mechanical properties.
• Optimizing sintering processes is crucial for bioceramic performance.

Purpose of the Study:

• To produce and characterize bovine-derived HA bioceramics with varying 3Y-TZP content.
• To investigate the effects of different sintering curves on HA-3Y-TZP composites.
• To evaluate the mechanical and microstructural properties of the developed bioceramics.

Main Methods:

• Bovine HA was extracted, nanoparticulated, and mixed with 0, 1, 5, and 10 wt% 3Y-TZP.
• Samples underwent uniaxial and isostatic pressing, followed by dilatometry analysis.
• Sintering was performed using conventional and two-step firing curves at different temperatures.
• Characterization included X-ray diffraction (XRD), biaxial flexural strength (BFS), Vickers microhardness (VH), and Field Emission Scanning Electron Microscopy (FE-SEM).

Main Results:

• Dilatometry indicated a need for sintering optimization with 3Y-TZP addition.
• XRD confirmed HA peaks in pure and 1% 3Y-TZP samples; higher additions caused HA decomposition.
• Pure HA (conventional sintering) and HA+1%3Y-TZP (2-step, 1420°C) showed optimal BFS and VH.
• The addition of 1 wt% 3Y-TZP and optimized sintering improved mechanical and microstructural properties while maintaining HA crystallinity.

Conclusions:

• 1 wt% 3Y-TZP addition, combined with optimized sintering, enhances bovine HA bioceramics' mechanical and microstructural characteristics.
• Higher 3Y-TZP concentrations lead to phase decomposition, negatively impacting properties.
• Further material processing refinements are necessary for successful clinical application in dentistry.