Study of the Mechanical and Microstructure Properties of Zirconia Reinforced with Glass and Silica

Abstract

Artificial teeth were manufactured from zirconia-yttria nanosystems by adding different types of glass to zirconia. The specimens were prepared from tetragonal zirconia crystals stabilized with 3% yttria (Y2O3) with the addition of soda-lime glass, Pyrex (1,5,10,15)%, and silica (1,2,3,4,5)% in different proportions. The specimens were formed using a pressure-balanced uniaxial hydraulic press (3 tons) the zirconia was sintered at (1500 °C) and the glass-containing systems were fired at (1100, 1200, 1400) °C for (2 hrs.). The structural properties (X-ray diffraction, scanning electron microscopy) and physical properties (apparent porosity, water absorption) were studied. The effect of artificial saliva, tea, and lemon (citric acid) on color stabilization was studied. When the specimens were immersed in a solution of artificial saliva, tea, and lemon for three months, the mechanical properties of the diametrical strength before and after immersion in artificial saliva and tea were studied, and the color stability after immersion was measured. The results show apparent porosity and water absorption ratio decreased from (0.14_ 0.01) and from (0.02_0.002) with (15%) soda lime glass added, the results showed (XRD) The tetragonal phase is the main phase with a small percentage of the monoclinic phase as a result of the addition of yttria and tetragonal zirconia has excellent mechanical properties such as fracture toughness. The (SEM) results indicate a homogeneous grain distribution. The results showed that the diametrical strength increased from (40 MPa) to (80 MPa) with (15%) soda lime glass after immersion was not affected diametrical strength after immersion for 90 days. Adding glass to zirconia resulted in a slight color change from bright white to white close to the color of natural teeth. This slight change took a long time.