Comparative Analysis of Different Implant Macrogeometry for Improved Esthetics, Inverted Body Shift, and Reverse Neck Collar Implant with Conventional Tapered Implant: A 3D Finite Element Analysis Study.

The effect of different implant macrogeometry varying in shape along with the biomechanical effect of reduced buccal cortical bone thickness has not been studied and compared in the literature. The purpose of this finite element analysis (FEA) is to understand the stress distribution on the surrounding cortical bone for implants specially designed for use in anterior maxillary region and compare them with the conventional tapered (CT) implants. Also to assess the advantage of these implants in compromised buccal bone conditions. Two 3D FEA bone block in the maxillary anterior region were meshed with D3 type of bone. One block with uniform cortical bone thickness all around whereas other with reduced buccal cortical bone. Three different implant, inverted body shift (INB) (4.5*3.8*13), reverse neck collar (4.5*4.2*13) and CT implant (4.5*13). Each design was meshed into the different bone blocks creating total of six meshed models. An oblique load of 178 N from palatal side in the buccopalatal direction was applied. INB implant showed the best performance in terms of minimum stress concentration on the surrounding buccal bone specially in the reduced buccal cortical plate situation. The CT implant showed highest percentage increase in stress concentration on reducing buccal plate thickness. The new implant designs specially designed for maxillary anterior region where sufficient buccal bone is often lacking proved to be advantageous in such conditions due to the possibility of additional bone formation around the implant. With its high stability it should be preferred for use in compromised conditions.