An In vitro Comparative Evaluation of Marginal Fit and Fracture Strength of Polyetheretherketone/BioHPP Fixed Partial Denture Framework with Cobalt–Chromium and Zirconia Fixed Partial Denture Framework

A BSTRACT Background: Polyetheretherketone (PEEK)/BioHPP, a high-performance polymer, has been recently adopted into dentistry from the automotive engineering industry. This material has been known to have mechanical properties comparable to conventional crown and bridge materials, but this has not been completely elucidated. Aims: The aim of this study was to compare the compressive strength and marginal adaptation of PEEK/BioHPP framework with that of the conventional cobalt–chromium (Co–Cr) alloy and zirconia frameworks. Materials and Methods: Fabrication of stainless steel master models and epoxy models was performed initially. The master model was scanned, and framework milling was done with the three materials (Co–Cr, zirconia, and PEEK). The fabricated frameworks were cemented on the epoxy resin models following which marginal adaptation and compressive strength were analyzed using standardized protocols before and after thermomechanical aging. The data were analyzed statistically using the R software. Results: BioHPP displayed the best marginal fit among the three materials, with molars exhibiting 69.39 ± 2.88 microgap prior to thermomechanical aging, which increased to 75.27 ± 1.69 after thermomechanical aging ( P < 0.05). In premolars, after cementation, it was 72.53 ± 0.95 microgap prior to thermomechanical aging, and after thermocycling, it rose to 77.86 ± 2.23 ( P < 0.05). Compressive strength was highest in the Co–Cr group, 2598.33 ± 185.22N ( P < 0.05), and lowest in the zirconia group (1187 ± 164.28 N). PEEK demonstrated compressive strength values (1236 ± 143.76 N) lower than Co–Cr alloy but higher than zirconia. Conclusion: The study results indicated that PEEK framework exhibited a better marginal fit compared to the base metal and zirconia frameworks. With respect to fracture strength, PEEK demonstrated a higher strength compared to zirconia and demonstrated values greater than the average masticatory force. Hence, PEEK can be recommended for usage in prosthetic dentistry as an efficient material for the fabrication of crowns and bridges, with due consideration must be given to long term clinical trials.