Evaluation of the Biomechanical Effects and Mechanical Distribution of Stress and Strain in SiC-Reinforced PEEK Implants Compared to Titanium Under Oblique Loading: A Three-Dimensional Finite Element Analysis Study

This study compares the biomechanical impact and mechanical distribution of SiC-reinforced PEEK implants to titanium implants using three-dimensional finite element analysis (FEA). Five different implant materials were investigated: titanium, pure PEEK, and PEEK reinforced with silicon carbide (SiC) particles at 2%, 4%, and 6% ratios. A wide range of oblique forces (45°) from 100 N to 900 N was applied to simulate physiological to extreme masticatory loads. The distribution of maximum von Mises stress and total deformation within the implant was examined. Structural integrity metrics linked to yield strength, including factor of safety (FOS), were also investigated. The biological evaluation included an analysis of the behavior of the bone tissue surrounding the implant by assessing maximum principal strain and maximum principal stress in cortical bone. The results show that titanium exhibited the highest stiffness and FOS (>1 up to 500 N) but induced the lowest bone strains (755–2275 µε at 100–300 N), indicating potential stress shielding. Pure PEEK resulted in excessive bone strains exceeding 4000 µε at moderate loads, suggesting bone overload risk. Among reinforced groups, PEEK + 4%SiC demonstrated the most balanced performance, reducing maximum principal bone stress by 28% compared to pure PEEK at 200 N, while maintaining bone strains within the physiological adaptive range (1000–3000 µε) under moderate loads. PEEK + 6%SiC showed increased stiffness but reduced ductility and safety factor. Within the limitations of this computational study, PEEK reinforced with 4% SiC appears to offer an optimal trade-off between mechanical stability and biomechanical compatibility. Further in vitro and clinical studies are warranted to validate these findings.