Comparison of stress patterns in the edentulous mandibular bone around four implant retained over denture and all-on-four concept – A three dimensional finite element analysis

Purpose: The purpose of this study was to compare the stress patterns on a four implant supported over denture with that of All-On-Four Concept. Method: The computed tomographic image of the human edentulous mandible was simplified into an arc shaped bone block of 7.5mm thick and 15 mm high with 1mm cortical bone layer. With the help of projector the implant design and dimensions were carefully recorded and same measurements were transferred to the FEA software. Three dimensional finite element analysis models of four implant supported over denture and the model with ALL-On-Four concept were prepared and were exposed to five different loading simulations. Results: From the study it was found that the stress levels during full mouth loading was the highest for the four implant supported over denture compared to the prosthesis with All-On-Four concept. The stress levels for the cantilever and non-cantilever were nearly the same for all the simulated designs.