The aim of this study was to compare the stresses on cylindrical and conical dental implants under heavy bruxing forces, in D1 and D4 bone densities, using three-dimensional finite element analysis (FEA). Eight different stress models were created according to implant design (cylindrical or conical), bone density (D1 or D4) and load (1000N, vertical or oblique). The von Mises stresses for each model were compared using FEA. The obtained results showed that D1 bone density and vertical force were associated with the least stress on the implant. Bone density was more important than implant design in stress formation. The results from the two implant types were very similar. The von Mises stress values were greater in the neck region of the implant. We suggest that the implant region should be considered firstly for less stress on the implant.