Abstract:

Objective To comparatively analyze the friction wear performance, fracture resistance, and displacement resistance before and after aging of full crowns made from PEEK, cobalt-chromium alloy, and zirconia, providing a theoretical basis for the future application of PEEK in crown fabrication. Methods Standard anatomical full crowns of PEEK, cobalt-chromium alloy, and zirconia were fabricated by preparing the upper first premolar and taking silicone rubber impressions, resulting in 25 crowns of each material. The crowns were divided into three groups: Group A (15 crowns, 5 from each material), Group B (30 crowns, 10 from each material), and Group C (30 crowns, 10 from each material, serving as a control). Group A underwent 120 000 chewing simulations under simulated oral physiological conditions, using a stereomicroscope and Micro-image Analysis & Process system to assess and compare wear of antagonists (opposing talc ceramic balls) and material wear. Group B underwent 10 000 thermal cycling aging tests and Group C were served as the control. Universal testing machines were used to evaluate and compare the fracture resistance and displacement resistance of Groups B and C. Results ①The wear heights of full crown materials were as follows: cobalt-chromium alloy (0.61±0.05)mm, zirconia (0.81±0.07)mm, and PEEK (0.96±0.04)mm, with PEEK>zirconia>cobalt-chromium alloy (P<0.05). For antagonist wear, the wear heights were cobalt-chromium alloy>zirconia>PEEK (P<0.05). ②The fracture resistance of cobalt-chromium alloy before and after aging was (3 665.645±71.166)N and (2 906.830±225.143)N, respectively; for zirconia it was (2 447.825±316.961)N and(1 829.229±72.046)N; and for PEEK crowns it was (1 632.378±53.046)N and (1 074.872±105.491)N, showing cobalt-chromium alloy>zirconia>PEEK (P<0.05). The displacement resistance for cobalt-chromium alloy before and after aging was (1 604.630±95.680)N and (1 092.137±77.869)N; for zirconia it was (1 768.851±56.273)N and (1 381.618±62.326)N; and for PEEK crowns it was (1 148.811±70.417)N and (931.723±64.454)N, indicating zirconia>cobalt-chromium alloy>PEEK (P<0.05). The aging degradation of cobalt-chromium alloy’s fracture and displacement resistance was (758.815±157.734)N and (512.492±34.530)N, respectively; for zirconia, it was (618.597±251.281)N and (387.233±7.947)N; and for PEEK crowns, it was (557.506±61.950)N and (217.089±14.589)N, with anti-aging performance: PEEK>zirconia>cobalt-chromium alloy (P<0.05). Conclusion The wear resistance, fracture resistance, and displacement resistance of PEEK meet the clinical standards for full crown materials, and PEEK demonstrates good anti-aging performance while effectively protecting opposing teeth. Therefore, PEEK has the potential to become a novel material for full crown fabrication

Key words: PEEK, biomaterials, chewing simulation, dental prosthetics