To assess the retentive force of telescopic crowns using polyetherketoneketone (PEKK) high-performance polymer (HPP) in relation to conventional materials over a long period of time in an in vitro setting.
MATERIALS AND METHODS
Thirty-six sets of primary and secondary crowns were fabricated as per the double crown-retained prostheses approach. Six samples were included in each of the five test groups (1: Zirconia/PEKK [Zr/PEKK]; 2: Titanium/PEKK [Ti/PEKK]; 3: Cobalt-chrome/PEKK [CoCr/PEKK]; 4: PEKK/PEKK; 5: Gold/PEKK [Au/PEKK]) and the single control group (Gold/Galvano-gold [Au/GA]). The insertion-removal test was performed for 20,000 cycles, and the surface condition was observed. Retentive forces were analyzed using two-way ANOVA (α<0.05).
RESULTS
The retention forces in groups Zr/PEKK and Ti/PEKK significantly decreased over time (group 1: p = 0.035, group 2: p = 0.001), whereas retentive force increased significantly in groups PEKK/PEKK, Au/PEKK, and Control (group 4: p = 0.001, group 5: p = 0.008, control: p = 0.042). Similar wear was observed on the primary crown in groups PEKK/PEKK, Gold/PEKK, and control.
CONCLUSIONS
Groups PEKK/PEKK and Au/PEKK showed a transition of retentive force similar to the control group. Groups PEKK/PEKK and Au/PEKK had similar wear on the surface compared to control. Therefore, PEKK has a promising clinical potential. This article is protected by copyright. All rights reserved.
