Kensuke Igarashi1, Hiroki Katagiri2,3, Samir Abou-Ayash4, Martin Schimmel4,5, Kelvin I Afrashtehfar4,6,7. 1. Department of Dental Materials Science, The Nippon Dental University, School of Life Dentistry at Niigata, Niigata, Japan. 2. Advanced Research Center, The Nippon Dental University, School of Life Dentistry at Niigata, Niigata, Japan. 3. Department of Histology, The Nippon Dental University, School of Life Dentistry at Niigata, Niigata, Japan. 4. Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland. 5. Division of Gerodontology and Removable Prosthodontics, University of Geneva, Geneva, Switzerland. 6. Clinical Sciences Department, Ajman University College of Dentistry, Ajman Emirate, UAE. 7. School of Biomedical and Health Sciences, Universidad Europea de Madrid, Madrid, Spain.
Abstract
PURPOSE: To assess the retentive force of telescopic crowns using polyetherketoneketone (PEKK) high-performance polymer 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; and 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 and 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, and 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.
PURPOSE: To assess the retentive force of telescopic crowns using polyetherketoneketone (PEKK) high-performance polymer 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; and 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 and 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, and 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.