Thread Design Optimization Of A Dental Implant

To optimize the thread design from a commercial dental implant for ideal stress distribution in the surrounding bone. The models of BLT® Φ4.1×10 implant (Institut Straumann AG) and alveolar bone were created. Dynamic von Mises stress (σvM) in the cortical bone during and immediately after implantation was calculated using explicit dynamics finite element analysis (EDFEA). The combination of thread pitch, depth, tip width (TW), and coronal/apical surface angle (CSA/ASA) which produced minimal σvM was determined as the optimal thread design. The implants with optimal and original thread designs were fabricated and implanted into rabbits’ tibias. Implant stability quotient (ISQ), bone-to-implant contact (BIC), and bone volume fraction in 500μm (BV/TV500) and 1000μm range (BV/TV1000) were measured to evaluate the osseointegration performance of the implants. The implant thread design of 0.8mm pitch, 0.2mm depth, 0.15mm TW, and 10° CSA/ASA, and 1.0mm pitch, 0.3mm depth, 0.2mm TW, zero CSA, and 20° ASA produced minimal σvM for the maxillary (OPTmax) and mandibular posterior region (OPTman), respectively. Optimized implants showed significantly improved ISQ value 4 weeks after implantation. The BV/TV500 and BV/TV1000 around the OPTmax, and the BIC and BV/TV500 around the OPTman implant were significantly higher than that around the original-designed implant, respectively. The thread design significantly affects the stress in the surrounding bone during and immediately after the implantation. The optimal thread design based on EDFEA promoted the osteogenesis around the implant.