developing a new dental implant design and comparing its biomechanical features with four designs

background: as various implant geometries present different biomechanical behaviors, the purpose of this work was to study stress distribution around tapered and cylindrical threaded implant geometries using three-dimensional finite element stress analysis.     methods: seven implant models were constructed using the cad system. after digitized models of mandibular section, the crowns were created. they were combined with implant models, which were previously imported into catia. the combined solid model was transferred to abaqous to create a finite element meshed model which was later analyzed regarding the highest maximum and minimum principal stresses of bone. results: for all models, the highest stresses of cortical bone were located at the crystal cortical bone around the implant. threaded implants, triangular thread form and taper body form showed a higher peak of tensile and compressive stress than non-threaded implants, square thread form and straight body form, respectively. a taper implant with triangular threads, which is doubled in the cervical portion of the body, had a significantly lower peak of tensile and compressive stress in the cortical bone than straight/taper triangular or square threaded implant forms. conclusion: for the investigation of bone implant interfacial stress, the non-bonded state should be studied too. confirmative clinical and biological studies are required in order to benefit from the results of this study.