임프란트 보철의 abutment 유무에 따른 유한 요소법적 응력분석

The attraction to endosseous implants lies in the potential for improved function, improved esthetic, and more favorable stress distribution in the superior prostheses, fixture, and supporting bone. Implant for single tooth replace is especially needed esthetics, and that was mainly established by use of various superstructure. The purpose of this study was to compare the stresses in implant prosthesis and fixture, and supporting bone according to with and without abutment between fixture and superstructure. Using the finite element method, this study modeled 4.0X14 mm cylindrical type implant fixture with the external hexed type of 0.75mm, and two models are completed. Model A is without abutment, so implant superstructure is direct connected in fixture, and Model B is with abutment on the fixture. The vertical load of 200N and 30° lateral load of 100N was applied at the cusp tip of the prostheses. The results were as follows ; 1. Under vertical and lateral loading, the amount of displacement was larger at the model B with abutment than at the model A without abutment. 2. Under vertical and lateral loading, less equivalent stress was represented at the model B with abutment than at the model A without abutment. 3. Under vertical and lateral loading, model B with abutment showed more stress in fastening screw than at the model A without abutment. 4. Under vertical and lateral loading, model B with abutment showed less stress distribution in fastening screw than at the model A without abutment. A s the results of this study, in case of using abutment between implant fixture and final prostheses, large displacement is occured and the stresses is concentrated at the fastening screw. The other hand, when the implant superstructure is direct connected to implantfixture without abutment, less displacement is occured and the streses is widely distributed to the supporting bone. That results means intermittent abutment acts stress blocker and when the use of abutment, fasening screw fracture more occured than supporting bone resorption.