Synthesis and Properties of Novel Calcia-Stabilized Zirconia (Ca-SZ) with Nano Calcium Oxide Derived from Cockle Shells and Commercial Source for Dental Application

Abstract

Various oxides are used to stabilize zirconium oxide (ZrO2), but their superior hardness causes wear of the machining tool. Calcia-doped zirconia has been studied but reports on properties suitable for dental application are lacking. Therefore, this study aimed to fabricate and characterize zirconia stabilized by calcium oxide (CaO) derived from cockle shells and compare it with zirconia stabilized by commercial CaO, sintered at different temperatures. In this study, 176 pressed pellets of zirconia mixed with CaO either derived from cockle shells or commercial CaO were sintered between 1200 and 1500 °C to produce calcia-doped zirconia. Characterizations were made with SEM and XRD. Specimens were subjected to density, compressive and flexural strength, and Vickers hardness testing. Data were analyzed using the independent t-test and one-way ANOVA. XRD revealed the zirconia was stabilized into tetragonal and cubic phases (Ca-SZ). Ca-SZ cockle shells (CS) and Ca-SZ commercial (CC) have average particle sizes of 267 nm and 272 nm, respectively, with similar surface roughness. At 1400 °C sintering temperature, flexural strengths were 1165 and 1152 MPa, compressive strengths were 4914 and 4913 MPa, and Vickers hardness were 977 and 960 MPa for Ca-SZ(CS) and Ca-SZ(CC), respectively. Both Ca-SZ materials showed no significant difference in most properties (p < 0.05) when sintered at different temperatures. The fully sintered Ca-SZ is less hard compared to the ceria-stabilized tetragonal zirconia polycrystal (Ce-TZP) available on the market. Thus, Ca-SZ may be used as an alternative to the current zirconia available on the market for dental application.

Synthesis and Characterization of Spherical Calcium Carbonate Nanoparticles Derived from Cockle Shells

“…The average particle sizes of CaO derived from cockle shells and commercially obtained CaO were 22-70 nm and 32-159 nm, respectively. The CaO obtained in the current study was used to stabilize zirconia, which showed good properties as a potential dental material [9].…”

“…Nanoparticles are important for producing materials with good properties [9]. The small particle size provides a larger surface area for the particles to be uniformly dispersed, and therefore may enhance the mechanical properties of the material [10], hence making the material more resistant to degradation [11].…”

Functionality and Activity of Sol–Gel-Prepared Co and Fe co-Doped Lead-Free BTO for Thermo-Optical Applications

“…In addition to the microstructure and grain size distribution, the cohesive forces within the grains of the ceramic pellets are mainly influenced by particle separation, pores, and shrinkage. Hussein et al 83 found that the largest value for compressive strength was mainly found for the irregularly distributed grains. In this study, the BTO ceramic pellet exhibited a higher compressive strength value (32.91 MPa) due to the microstructure and morphology of BTO which primarily contains irregularly oriented flat block grains; this fact contributes significantly to the weakening of the bond between atoms.…”

Optimized preparation of MgO-ZrO2 nanocomposite powders by assisted sol-gel method

“…Therefore pure zirconia cannot be applied to the preparation of ceramic products. The addition of stabilizers such as Y2O3, MgO, CaO, and CeO2 is an effective measure to stabilize the tetragonal phase zirconia at room temperature [4][5][6][7]. Y2O3 is the most widely used, but yttrium oxide stabilized zirconia ceramics suffer from low-temperature ageing, which strongly limits their application in areas such as bioceramics, and there are few reserves of Y2O3, which is not conducive to sustainable development.…”