Influence of arch shape and implant position on stress distribution around implants supporting fixed full-arch...

This finite element analysis was conducted to determine changes in stress concentration in relation to different alveolar arch shapes of the maxilla.

Five different maxillary alveolar arch shape measurements coded as shortest ellipsoid shape and medium width, longest ellipsoid shape and narrow, U-shaped long and narrow, U-shaped short and wide, and U-shaped medium length and medium width were obtained, and 5 different implant distribution strategies coded on the basis of a tooth number as 3,4,5; 2,3,4; 1,3,5; and 2,4,5 (total of 6 implants) and 2,3,4,5 (total of 8 implants) were plotted in each of the 5 maxillary arch models. The implants were assumed to support a 12-unit bridge with first molars region being the cantilever area. Combination of 5 different arch shapes, 5 different implant distributions, and 2 different loading points (anterior and posterior) led to 50 different simulated scenarios that are all solved and compared.

In case of either anterior or posterior loading, the most favorable implant distribution strategies for the arch models are as follows: 2,4,5 and 2,3,4,5 for longest ellipsoid shape and narrow; 2,4,5 and 2,3,4,5 for shortest ellipsoid shape and medium width; 1,3,5 and 2,3,4,5 for U-shaped long and narrow; 2,3,4,5 and 2,4,5 for U-shaped medium length and medium width; and 1,3,5 and 2,3,4,5 for U-shaped short and wide.

Distribution of implants in 2,4,5 order seemed to be fairly favorable for ideal stress distribution in all simulated models.