A comparison is going to be made between the loss of preload on a 7-mm distal cantilever in two different connection systems using an all-on-four prosthetic model when there is no loading and after a set number of cyclic loadings have been performed on the cantilever. Methods: An edentulous mandible was rehabilitated using an all-on-four technique with two different types of abutment systems (MUA and OT-Bridge) in order to support hybrid prosthesis. Two equal models of an edentulous mandible were used. Using a mechanical torque gauge, initial torque values of the prosthetic fixing screw were registered after ten minutes of initial screw tightening, after 400,000 repeated loadings, and after the initial screw tightening. Differences between the initial and final torque values were reported for each anchoring system, and the results of the comparison between the two systems were presented. After 400,000 cyclic loadings, the results showed that there was no statistically significant difference in the loss of preload between the MUA system and the OT-Bridge system. However, in the MUA system, a statistically significant difference was found between the anterior and posterior implant screws. Only for the MUA system was a statistically significant difference in preload loss found when comparing the initial screw torque to that measured after 10 minutes from the tightening in the absence of cyclic loadings. This was the case. Within the scope of the present investigation, the findings suggest that the MUA and OT-Bridge may be considered reliable prosthetic anchoring systems that are able to withstand repeated cyclic occlusal loads on the distal cantilever in an all-on-four rehabilitation model without experiencing any significant loss of preload in screw tightening.