Evaluation of Stress Distribution on all-on-four Concept and Conventional Implant Designs: 3D Finite Element Analysis

Summary Background/Aim: The objective of this study was to evaluate the stress distribution on implants and supporting bone tissue in All-on-Four and conventional designs in edentulous mandible by using 3D finite element analysis. Material and Methods: The different five models were designed according to All-on-Four concept and conventional implant placement designs. While the first two models were involved in All-on-Four concept with two long implants, the remaining models were designed by conventional approaches with three implants in different location and length. After the modelling procedures, a load of masticatory force was applied and the stresses were evaluated. Results: It has been observed that principal stresses in both cortical and spongious bone tissue were concentrated in models of All-on-Four design. Less principal stress levels were found in models of conventional design. Similarly, von Mises stress values on implant surfaces were found to be higher in All-on-Four concept. Conclusions: In severely resorbed mandible, the use of conventional implant placement is recommended. Although All-on-Four design seems to be a reasonable alternative for edentulous mandible, evidence-based results of this approach should be supported by long-term follow-up studies.