An Investigation of Stress Distribution Between Two Different Implant Concept in Implant-Supported Maxillary Prostheses with Different Framework Materials: A Finite Element Study.

Purpose: The purpose of this study is to compare the stress distribution between all-on four and all-on six treatment concept with various prosthetics framework materials through finite element analysis.

Materials and methods: A three-dimensional finite element model of edentulous maxilla was simulated using computerized topographical data of a patient. Four implants were placed according to All-on four concept. In addition to the all-on four concept, two more axial implants were placed in anterior region to create the all-on six concept. Four framework materials were investigated: Cobalt-Chrome (CoCr), Zirconium (Zr), Titanium (Ti) and Polyetheretherketone (PEEK). 100 N load was applied at anterior region, 150 N oblique load was applied at premolars and 200 N oblique load was applied at molars region simultaneously. Principal stresses in bone, the Von Mises stresses in implant and frameworks were calculated and compared.

Results: All-on six concept showed lower von Mises on implant, and framework, and principal stress values on the bone, than all-on four concept. PEEK exhibited highest stress values on bone and implants, while CoCr showed least stress values.

Conclusion: Stress distribution was influenced by the framework materials. The use of framework material with appropriate physical properties on the correct indication might be particularly important in determining the success of the implant-supported prostheses.