Prospective 10-year cohort study based on a randomized, controlled trial (RCT) on implant-supported full-arch maxillary prostheses. part II: prosthetic outcomes and maintenance.

BACKGROUND

Long-term follow-up studies (i.e., over 5 years), focusing on prosthetic outcomes and maintenance of implant-supported reconstructions in the edentulous maxilla, are scarce in the literature.

PURPOSE

The purpose of this study was to evaluate and report 10-year data on outcomes and maintenance of screw-retained implant-supported full-arch casted titanium-resin prostheses in the edentulous maxilla.

MATERIALS AND METHODS

In the randomized control trial cohort of 24 patients, the outcome and maintenance of 23 bridges were registered.

RESULTS

One patient dropped out of the study prior to the 10-year control. Of the 23 remaining patients, 21 still had their original frameworks; one framework fractured after 8 years and one was remade after 7 years to create better support for the acrylic. The remaining 23 prostheses showed criteria of success, survival, and failure in 9, 82, and 9%, respectively. Tightening of two assembly screws was necessary in one patient. No detrimental effects were seen because of long cantilever extensions or opposing dentition. A total of 4.7 resin-related complications per prosthesis were observed; tooth fracture was the most common prosthetic complication. There was an indication of greater prevention in the number of resin-related complications with the use of lingual gold onlay compared with a resilient mouth guard, 0.71 and 1.67, respectively per bridge. The bridges were removed and reinserted 0.83 times per patient. No abutment or abutment screw fractures were registered.

CONCLUSION

Fracture or wear of the reconstruction materials were considered predictable risks when using resin-based suprastructure materials. Status of opposing dentition and length of cantilevers did not confer additional risk. The use of a lingual gold onlay indicated prevention of resin-related complications. Future research should focus on the suprastructure materials to predict better overall treatment results of implant-supported full-arch bridges in the edentulous maxilla.