Influence of Aging on the Fracture Characteristics of Polyetheretherketone Dental Crowns: A Preliminary Study

Although polyetheretherketone (PEEK) is becoming more widely used in dentistry applications, little is known about how aging will affect this material. Therefore, this study aimed to investigate the influence of an aging treatment on fracture characteristics of PEEK dental crowns. Additionally, the impact of the addition of titanium dioxide (TiO(2)) into PEEK was examined. Two types of commercial PEEK discs were used in this study, including TiO(2)-free and 20% TiO(2)-containing PEEK. The PEEK dental crowns were fabricated and aging-treated at 134 °C and 0.2 MPa for 5 h in accordance with the ISO 13356 specification before being cemented on artificial tooth abutments. The fracture loads of all crown samples were measured under compression tests. Results demonstrated that adding TiO(2) enhanced the fracture load of PEEK crowns compared to TiO(2)-free PEEK crowns before the aging treatment. However, the aging treatment decreased the fracture load of TiO(2)-containing PEEK crowns while increasing the fracture load of TiO(2)-free PEEK crowns. The fracture morphology of TiO(2)-containing PEEK crowns revealed finer feather shapes than that of the TiO(2)-free PEEK crowns. We concluded that adding TiO(2) increased the fracture load of PEEK crowns without aging treatment. Still, the aging treatment influenced the fracture load and microscopic fracture morphology of PEEK crowns, depending on the addition of TiO(2).