Selections of the cylinder implant neck taper and implant end fillet for optimal biomechanical properties: a three-dimensional finite element analysis.

In this paper, effects of the implant neck taper and the implant-end fillet on the maximum Von Mises stresses were evaluated in jaw bones, and maximum displacements examined in an implant-abutment complex by a finite element method (FEM). The implant-neck tapers (T) ranged from 45 degrees to 70 degrees , and fillets of implant ends (R) ranged from 0.5 to 1.5mm. Results suggested that under axial load by the maximum Von Mises stresses in cortical and cancellous bones decreased by 71.6% and 14.8%, respectively, and under 45 degrees 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 45 degrees buccolingual load, respectively. When T ranged from 64 degrees to 73 degrees and R exceeded 0.8mm, minimum stress/displacement was obtained and the evaluating targets were more sensitive to T than to R. Data indicated that 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 64-73 degrees and fillet of implant end exceeding 0.8mm were optimal selections for the type B/2 bone in a cylinder implant by biomechanical consideration.