Load-Bearing Capacity of Posterior CAD/CAM Implant-Supported Fixed Partial Dentures Fabricated with Different Esthetic Materials

Purpose: To compare the load-bearing capacity after long-term use (5-year simulation) of posterior threeunit implant-supported fixed partial dentures (FPDs) fabricated with different esthetic materials. Materials and Methods: A total of 20 specimens fabricated from one design file using CAD/CAM were divided into four groups: polyetherketoneketone (PEKK) veneered with composite resin (CR); PEKK veneered with lithium disilicate (LD); zirconia veneered with fluorapatite (FA); and monolithic zirconia. Samples were placed into a chewing simulator with simultaneous thermocycling. The fracture load after aging was measured using the universal testing machine with load on the central fossa of the pontic. Results: FPDs fabricated with PEKK + LD had significantly higher fracture load (1,526.56 [SD 95.54] N) compared to PEKK + CR (1,069.54 [SD 67.94] N) (P .05). FPDs fabricated with zirconia materials had significantly higher fracture load compared to PEKK materials (P .05). There was no significant difference between monolithic zirconia and zirconia + FA (P > .05). Conclusion: FPDs fabricated with PEKK + LD were superior to PEKK + CR. These materials can be promising alternatives for use as implant-supported FPD materials in the high-stress- bearing posterior region. Zirconia + FA can be an alternative to monolithic zirconia in cases that require more esthetics.