Design and Analysis of Porous Structure Implant Based on Primitive Triply Periodic Minimal Surface

In this research, the performance of a porous implant in the human body is investigated in order to use a specific type of lattice structure to the implant most commonly used in bone scaffolds. Triply Periodic Minimal Surface (TPMS) for constructing lattice structure in implant were used. The equations of Schwarz Primitive (P-TPMS) were solved using the Grasshopper plugin, and finally the surface of a Schwarz Primitive cell is obtained to design porous structure. One conventional and two porous dental implants with 54% and 65% porosity were modelled based on ITI standard. The boundary conditions for dental implant analysis were based on chewing pattern. The results indicated that after implantation of dental implants, the average stress during loading, increased in the porous implants compared to the usual implant, where von Mises stress increased from 59 to 92 MPa. In addition, in terms of porous implant analysis, the stress distribution in the bone is increased. By making the dental implants porous, it is possible to encounter Stress Shielding phenomena. In this phenomenon, the implant, due to the increased stiffness of the porous implant compared to the mandible bone, it prevents the transfer of stress to the bone, which results in weakened bone in the implant surroundings. By applying porosity and TPMS unit cell in implant design, it leads to drop in attracting stress in the porous implant relative to the conventional implant. On the other hand, the ingrowth of bone and resulting mechanical coupling throughout bone and implant, results in more even stress distribution.