Is it beneficial to support interforaminal implant placement techniques with ultra-short implants in the posterior region? A 3D finite element analysis

Aim This study aims to evaluate the effects of ultra-short implants in the posterior region to eliminate the distal prosthetic cantilevers in interforaminal implant placement techniques on the stresses on the peri-implant bone, implants, and prosthetic structures.

Method Six models were created in a digital environment. In the interforaminal region, 3 and 4 vertically placed implants and All-on-4 techniques are modeled. In addition, models in which 4 mm implants support these techniques, in the posterior region, to eliminate cantilever extensions are simulated. In all models, the prosthetic emergence of posterior implants was simulated at the same point. Screw-retained fixed prostheses were placed on the implants. A spherical foodstuff force was applied to imitate the chewing forces from the canine and molar regions. The three-dimensional finite element method analyzed the stresses on bones, implants and prosthetic structures.

Results The effects of supporting interforaminal implant placement techniques with ultra-short implants on peri-implant bone stresses were limited. On the other hand, significant stress differences were observed in stresses on implants, multiunit abutments, and prosthetic framework, especially against molar region forces.

Conclusion Supporting the cantilever extensions of interforaminal implants in the posterior region with ultra-short implants has been shown to have the potential to reduce technical complications on prosthetic structures significantly. Supporting interforaminal implant placement concepts with short implants in the posterior region could be a more risk-free approach, especially in extra-risky cases such as bruxism.