Retention Load of Telescopic Crowns with Different Taper Angles between Cobalt-Chromium and Polyetheretherketone Made with Three Different Manufacturing Processes Examined by Pull-Off Test

Wagner, Christina; Stock, Veronika; Merk, Susanne; Schmidlin, Patrick R.; Roos, Malgorzata; Eichberger, Marlis und Stawarczyk, Bogna (2018): Retention Load of Telescopic Crowns with Different Taper Angles between Cobalt-Chromium and Polyetheretherketone Made with Three Different Manufacturing Processes Examined by Pull-Off Test. In: Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry, Bd. 27, Nr. 2: S. 162-168

Abstract

PurposeTo investigate the retention loads of differently fabricated secondary telescopic polyetheretherketone (PEEK) crowns on cobalt-chromium primary crowns with different tapers. Materials and Methods: Cobalt-chromium primary crowns with 0 degrees, 1 degrees, and 2 degrees tapers were constructed, milled, and sintered. Corresponding secondary crowns were fabricated by milling, pressing from pellets, and pressing from granules. For these nine test groups, the pull-off tests of each crown combination were performed 20 times, and the retention loads were measured (Zwick 1445, 50 mm/min). Data were analyzed using linear regression, covariance analysis, mixed models, Kruskal-Wallis, and Mann-Whitney U-test, together with the Benferroni-Holm correction. Results: The mixed models covariance analysis reinforced stable retention load values (p = 0.162) for each single test sequence. There was no interaction between the groups and the separation cycles (p = 0.179). Milled secondary crowns with 0 degrees showed the lowest mean retention load values compared to all tested groups (p = 0.003) followed by those pressed form pellets with 1 degrees. Regarding the different tapers, no effect of manufacturing method on the results was observed within 1 degrees and 2 degrees groups (p = 0.540;p = 0.052);however, among the 0 degrees groups, the milled ones showed significantly the lowest retention load values (p = 0.002). Among the manufacturing methods, both pressed groups showed no impact of taper on the retention load values (p > 0.324 and p > 0.123, respectively), whereas among the milled secondary crowns, the 0 degrees taper showed significantly lower retention load values than the 1 degrees and 2 degrees taper (p < 0.002). Conclusion: Based on these results, telescopic crowns made of PEEK seem to show stable retention load values for each test sequence;however, data with thermo-mechanical aging are still required. In addition, further developments in CAD/CAM manufacturing of PEEK materials for telescopic crowns are warranted, especially for 0 degrees.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 1059-941X
• Sprache: Englisch