Retention forces are significantly affected by abutment type because the metal retainer was more retentive than plastics, possibly providing better fixation of the prosthesis in position, and more difficult to remove. After 6 months of simulation, retentiveness of both plastic components was similar. There was no fracture of any component.

The present results have shown that not wearing a maxillary CD at night is preferable as far as SB and OSAS are concerned, but larger-scale studies are still needed.