QCT/FEA analyses of palateless splinted and unsplinted maxillary all-on-4 systems

The goal of the presented study was to determine the viability of using splinted and unsplinted maxillary implant-supported overdentures. The main physical quantity used to evaluate their differences was compressive stress in bone and equivalent (von Mises) stress in the implant and overdenture components. We took a 3D X-ray scan of the maxilla and imported the data into a QCT/FEA (Quantitative Computed Tomography-based Finite Element Analysis) software. The loading was done in three load cases. We designed both models of the overdentures in CAD, included the polyetheretherketone (PEEK) overdenture and analyzed the whole model of the reconstructed maxilla with implants. The results show worse (more concentrated) compressive stress distributions for the unsplinted locator variant. The splinted, bar-retained variant shows lower values of stress in all load cases. These findings and their potential for real-time selection of the optimal variant are then further discussed.