EFFECT OF DIFFERENT COMPACTION PRESSURES ON PHYSICOMECHANICAL PROPERTIES OF AKERMANITE BIOCERAMICS USING CALCIUM DERIVED FROM DENTAL MOULD WASTE

Abstract

This study aimed to produce akermanite bioceramics derived from dental mould waste (DMW) via high-energy planetary ball milling followed by subsequent sintering. Alkaline roasting and caustic leaching were utilised to extract calcium from dental mould waste prior to synthesise akermanite. Uniaxial pressing was used to prepare the green compacts with different compacting pressures of 200 and 250 MPa. The pellets were sintered in a chamber furnace at 1225 °C for three hours with a constant heating and cooling rate of 5 °C/min. The effects of compaction pressure on the physical and mechanical properties of the sintered akermanite were investigated. X-ray diffraction (XRD) analysis revealed that the major phase of these sintered samples is crystalline akermanite, with diopside as a minor phase. The microstructural analysis of the fractured surfaces for the sintered akermanite bioceramics exhibited a transgranular fracture mode, indicating the presence of strong grain boundaries and leading to high mechanical strength. Considering the quality of the pellet and slightly higher DTS value, 200 MPa was selected as the preferable compaction pressure rather than 250 MPa. At this condition, the sintered akermanite possesses a diametral tensile strength of 5.25 ± 0.53 MPa, which falls in the range of the human cancellous bone (2-12 MPa), while higher 250 MPa, the diametral tensile strength was 5.18 ± 0.31 MPa.