Evaluation of shear bond strength of denture base materials to polymer and CoCr RDP frameworks

Abstract

New removable dental prosthesis (RDP) framework materials are being released that can be fabricated by computer assisted design and manufacturing (CAD/CAM). These materials are proposed to replace traditional cobalt chromium (CoCr) frameworks. However, their properties must be tested to ensure that they are comparable to traditional framework. The ability to bond to veneering resins, is important in the repair of a removable dental prosthesis. CoCr enveloped by poly-methyl methacrylate (PMMA) is traditionally the gold standard for RDP repairs. A new polymer framework material (Ultaire AKP, Solvay Dental 360) was used for a shear bond test to compare both the bond strength of CoCr and AKP to not only PMMA (Probase Cold, Ivoclar Vivadent), but also to a denture composite, in this case Nexco (Ivoclar Vivadent). Samples of CoCr and AKP were embedded in autopolymerizing PMMA cylinders. PMMA and Nexco were bonded to each substrate using their individual manufacturer instructions. Shear bond test results indicate that PMMA with a metal bonding liner called UBAR (Protech Professional Products, Inc) had the strongest bond in the CoCr samples, while the Nexco composite had the strongest bond within the AKP samples. Further testing must be done to evaluate flexural strength of this material as well as other applications of polymer frameworks.