Based on the application requirements for porous dental implants, four porous structures of gyroid, RD (rhombic dodecahedron), cubic, and CHC (three identical cylinders hollow cubic) for porous titanium implants have been designed and fabricated using selective laser melting (SLM) technology. Typically, the unit cell dimensions range from 0.5 to 1.6 mm, with pore diameters between 300 and 900 µm, achieving porosities of 60%−80%. The influence of porous structures with small unit cell on scaffold formability and mechanical properties was investigated through compression, torsion tests as well as finite element simulations. Consequently, gyroid scaffolds exhibit optimal formability with the lowest porosity and pore deviation. With the same porosity, gyroid and RD scaffolds exhibit lower compressive strength than cubic and CHC scaffolds, yet their torsional properties show an inverse relationship. Moreover, gyroid scaffolds possess the highest torque but the lowest compressive strength and elastic modulus. The gyroid scaffold with 60% porosity shows a modulus of 3.96 GPa, matching bone modulus of 0−30 GPa. Its compressive strength reaches 176.3 MPa, exceeding that of bone by 100 MPa. Additionally, the torque for the d 4.0 mm implant is 2.22 N·m, approaching the FDA safe torque of 2.3 N·m. Therefore, the gyroid represents the most ideal structure for porous dental implants.
LIAO et al. (Wed,) studied this question.