Novel ceria-stabilized tetragonal zirconia/alumina nanocomposite as framework material for posterior fixed dental prostheses: Preliminary results of a prospective case series at 1 year of function

Objective: To examine the clinical performance of veneered ceria-stabilized tetragonal zirconia/alumina-nanocomposite (Ce-TZP/A-nanocomposite) frameworks for three-unit fixed dental prostheses (FDPs). Method and Materials: Eight patients in need of one FDP replacing one premolar or molar were included in this case series. Eight Ce-TZP/A- nanocomposite FDP frameworks were fabricated with a CAD/CAM system (Hint-Els) and veneered with a zirconia veneering ceramic (Vintage ZR, Shofu). The FDPs were cemented with resin cement (baseline) and were evaluated at baseline; 2 weeks; and 3, 6, and 12 months after cementation. For the technical evaluation, the USPHS criteria were used. The biologic outcome was judged by comparing the plaque control record (PCR), bleeding on probing (BOP), and probing pocket depth (PPD) of the abutment teeth (test) and untreated contralateral teeth (control). Radiographs were made at baseline and at 6 and 12 months of follow-up. The data were descriptively analyzed. Results: The mean observation period of the eight examined FDPs was 12.8 ± 1.1 months. The survival rate of the FDPs was 100%. Furthermore, no technical or biologic complications were found. No differences of the mean (m) PCR (test: 0.1 ± 0.1, control: 0.2 ± 0.2), mBOP (test: 0.2 ± 0.2, control: 0.1 ± 0.1), and mPPD (test: 2.6 ± 0.8, control: 2.6 ± 0.6) were found between test and control teeth. Conclusions: Ce-TZP/A nanocomposite was found to be a reliable framework material at 1 year of function. Longer observation periods and randomized controlled clinical trials including more patients are needed to validate these findings. Keywords: CAD/CAM, ceria-stabilized, fixed dental prosthesis, framework, zirconia, zirconia/alumina nanocomposite