Longevity of Two-Unit, Posterior All-Zirconia RBBs

Objectives: The study reports a proof-of-principle cohort study for posterior two-unit cantilever (CL2) all-zirconia resin-bonded bridges (RBBs).
Methods: Patients with one or more single edentulous spans were accepted according to inclusion/exclusion criteria (IRB: UW15-205). Patients accepting treatment were treated by students or dentists in residence. Prostheses were designed to include occlusal coverage or a D-shaped retainer following the traditional metal-ceramic RBB design.
Baseline clinical data was recorded to determine: longevity and clinical outcomes; success (restoration present no intervention), survival (restoration present with intervention – recementation or repair) and failure (restoration missing or not suitable for recementation). In addition, patient’s satisfaction and OHIP-49 data were collected.
Results: At baseline 45 patients with 49 premolar-sized edentulous spans were assessed, 36 subjects were recruited with 40 edentulous spans. 69.4% were female with a cohort mean age of 47.5y. 32 prostheses were reviewed at six months, 31 prostheses at one-year and 32 prostheses two-year review. At two years, one prostheses debonded and was recemented (survived) and one abutment had biological complications but the prosthesis was intact. All bridges survived up to 2 years and success rate was 93.8% (30 out of 32).
Patient-reported prosthesis satisfaction was satisfactory with a general satisfaction score of 81.8 out of 100 (SD 11.9). The summary OHIP score of patients decreased from 43.0 to 36.3 indicating an improvement in oral health-related quality of life (p=0.11) with significant improvement in psychological disability (p=0.03).
Conclusions: Short-term clinical data show that all zirconia RBB to have promising longevity with good patient satisfaction and QoL. Longer term follow-up is planned.