Distribution of stresses in extra-short wide-diameter dental implants made of carbon fiber-reinforced PEEK: a finite element analysis

Aim: This study evaluated the stress distribution in wide-diameter extra-short dental implants (ESDI) made of titanium grade IV (Ti) and carbon-fiber reinforced polyetheretherketone (PEEKc) as support for lower first molar crowns under 30° oblique load. Materials and methods: Four models were created, varying the implant diameter as regular Ø4 mm (RD) or wide-diameter Ø6 mm (WD), and the implant and abutment material (Ti and PEEKc). The abutment and implant were evaluated using von Mises stress (σvM), while the cortical and cancellous bone were evaluated using minimum principal stress (σmin) and maximum shear stress (τmax). A qualitative assessment was performed based on the distribution and color temperature patterns. Results: Compared to Ti, the PEEKc abutment showed a reduction in σvM of 13.17% when WD and ESDI was used. The WD PEEKc implant showed a reduction of at least 15.06%. In cortical bone, PEEKc with WD showed a minimum reduction of 20.02% and 27.97% in τmax and σmin, respectively. In cancellous bone, PEEKc showed a reduction in τmax of at least 5.26% while in σmin there was a reduction of at least 2.89% regardless of diameter. Conclusion: PEEKc ESDIs with WD demonstrated better stress distribution in the implant, abutment, and cortical bone compared to Ti implants, when used as support for lower first molar crowns.