Comparison between screw-retained and conometric technique in full-arch implant prosthetic rehabilitation regarding operative time needed: an in-vitro study.

BACKGROUND

A common issue with full-arch implant rehabilitations is the inconvenience of prosthesis removal, which must be performed every 6-12 months to ensure proper hygiene. The purpose of this study was to compare the most used technique for full arch prostheses, the screw-retained, with the conometric technique, less discussed in the literature, which could give advantages in terms of removal and reinsertion time.

METHODS

The main component used was the implant-prosthetic connection Orbit (Bionica), which allowed for testing both conometric and screw-retained techniques. The first phase of the study (activation phase) focused on testing the activation of the copings in a standardized manner using a prosthetic driver at different torque values, from 10 Ncm to 30 Ncm, and then pulled to observe the force was required for decoupling. The second phase (time phase) compared the techniques to determine whether there were differences based on operators' experience, and secondly, which technique was faster.

RESULTS

The activation phase resulted in a 15 Ncm value in which there was no deformation of the coping. The time phase showed that the screw-retained technique is quicker in delivery than the conometric technique (average of 6 min 4 s vs. 13 min 56 s for the all-on-four, average of 8 min 0 s vs. 18 min 37 s for the all-on-six), but on the other hand, the conometric technique is faster in check-ups (average of 9 min 2 s vs. 0 min 30 s for the all-on-four, average of 12 min 41 s vs. 0 min 43 s for the all-on-six).

CONCLUSIONS

With the chosen components, it is possible to fabricate a prosthesis in a less operator-dependent manner. Because of the working times required, we hypothesize that the screw-retained technique should be preferred for provisional prosthetic restorations, while the conometric technique for permanent restorations.