Fit of complete-arch implant-supported prostheses produced from an intraoral scan by using an auxiliary device and from an elastomeric impression: A pilot clinical trial

Statement of problem. The accuracy of impressions for implant-supported prostheses is essential to ensure a passive fit of the definitive prosthesis. Intraoral scanners (IOSs) have been developed as an alternative to complete-arch implant-supported restorations; however, whether they are sufficiently accurate when more than 3 nonaligned implants are involved is unclear.Purpose. The purpose of this pilot clinical study was to determine whether the fit of complete-arch zirconia implant-supported frameworks processed on a cast obtained with an IOS and adjusted with an auxiliary device is equivalent to a prosthesis obtained from an elastomeric impression.Material and methods. Twelve consecutive participants who were ready for complete-arch restorations on already osseointegrated implants were enrolled. Two records were made, one open-tray with polyether and splinted impression copings and the second with an IOS. A verification gypsum device was used for the elastomeric impression, and a prefabricated auxiliary device was used to adjust the intraoral scans. Two zirconia frameworks with the same design were processed and evaluated intraorally by 2 independent calibrated observers.Results. In 11 of the 12 participants, the digitally processed prosthesis was preferred over the conventionally processed prosthesis. The clinical fit of the prostheses obtained with the completely digital workflow was better than that of those obtained with the conventional workflow.Conclusions. The use of a prefabricated auxiliary device after intraoral scanning allowed delivery of complete-arch implant-supported monolithic zirconia prostheses with a fit better than those fabricated from conventional impressions. (J Prosthet Dent 2022;128:404-14)