Optimal Biomechanical Selections of Implant Neck Taper and End Fillet

Objectives:To find the optimal biomechanical properties of the implant neck taper and end fillet by a finite element method (FEM). Methods:The implant neck tapers (T) ranged from 45⁰ to 70⁰, and fillets of implant ends (R) ranged from 0.5 to 1.5 mm.The maximum Von Mises stresses in jaw bones, and maximum displacements examined in an implant-abutment complex were evaluated. Results:Under axial load, the maximum Von Mises stresses in cortical and cancellous bones decreased by 71.6% and 14.8%, respectively, and under buccolingual load by 68.2% and 11.0%, respectively. The maximum displacement of implant-abutment-complex decreased by 9.1% and 22.8% under axial and buccolingual load, respectively. When T ranged from 64⁰ to 73⁰ and R exceeded 0.8 mm, minimum stress/displacement were obtained and the evaluating targets were more sensitive to T than to R. Conclusions:The taper of implant neck favored stress distribution in cortical bones more than the fillet of implant end did; taper of implant neck affected implant stability more than the fillet of implant end did; and the taper of implant neck of 64-73⁰ and fillet of implant end exceeding 0.8mm were optimal selections for the type B/2 bone in a cylinder implant by biomechanical consideration.