Does the prosthesis weight matter? 3D finite element analysis of a fixed implant-supported prosthesis at different weights and implant numbers

摘要

This study evaluated the influence of prosthesis weight and number of implants on the bone tissuemicrostrain. MATERIALS AND METHODS. Fifteen (15) fixed full-arch implant-supported prosthesis designs werecreated using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15,20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elementsformed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior.The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implantinterface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along theZ-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria. RESULTS. Theprosthesis weight was related to the bone strain. The more implants installed, the less the amount of straingenerated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with thelargest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce boneremodeling simply due to the prosthesis weight. CONCLUSION. Heavier prostheses under the effect of gravityforce are related to more strain being generated around the implants. Installing more implants to support theprosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generateharmful values of peri-implant bone strain.