A comprehensive mechanical characterization of as-printed and saliva soaked 3D printed PEEK specimens for low-cost dental implant applications

Dental implants play an important role in the reconstruction of the lost tooth. The implant materials and manufacturing techniques are of significant importance in the performance of the implants. Conventional dental implant materials such as titanium and zirconia exhibit many limitations such as allergies, peri-implant bone loss, and implant fractures. Implant fractures are caused due to stress shielding arising from the significant difference in mechanical properties between the implant and jawbone. However, polymeric materials can overcome the limitations of metallic implant materials. In this work, Polyether ether ketone (PEEK) specimens are manufactured using the fused deposition molding (FDM) technique, and the effect of printing parameters on its mechanical properties are investigated for dental implant applications. Three different raster angles, (0 & DEG;/0 & DEG;), (45 & DEG;/-45 & DEG;), and (90 & DEG;/90 & DEG;), were considered, and an array of mechanical characterizations are performed on the printed specimens to find tensile, compression, flexural, hardness, and saliva absorption properties for as-printed and saliva soaked conditions. 3D-printed PEEK specimens with a (45 & DEG;/-45 & DEG;) raster angle displayed a superior mechanical properties compared to other raster angle specimens. Results showed that 3D printed PEEK exhibits similar properties to natural human tooth enamel, while extruded PEEK exhibits characteristics similar to natural dentin and cortical bone. The 3D printed PEEK crown's potential to withstand compressive loads during biting (-50 N) was also evaluated and found that the PEEK has adequate mechanical properties to be a better low-cost implant material than titanium and zirconium.