Stress Analysis of Axial and Tilted Implants in Full-arch Fixed Dentures Under Different Abutment Conditions.

The aim of this study was to evaluate the stress distribution on full-arch prostheses, considering axial implants and tilted implants with or without abutments. Two photoelastic models were made, being that in 1 model the implants were inserted perpendicular, whereas in the other model 2 implants were inserted perpendicular and 2 implants were inserted with tilting 30° to the distal area. The prosthetic situations were evaluated: A-axial implants and nonsegmented full-arch prosthesis; B-axial implants and segmented full-arch prosthesis; C-tilted distal implants and nonsegmented full-arch prosthesis; D-tilted distal implants and segmented full-arch prosthesis, and was applied an axial load of 100 N at 5 points. The results showed greater stress concentration for axial implants than tilted implants in anterior and posterior loading. There was no difference in stress distribution to the use of abutment in the tilted implants. Shorter cantilever with tilted implants improved the stress distribution; the use of abutment did not influence the stress distribution.