The influence of the restorative material on the mechanical behavior of screw-retained hybrid-abutment-crowns

J Mech Behav Biomed Mater. 2020 Nov:111:103988. doi: 10.1016/j.jmbbm.2020.103988. Epub 2020 Jul 26.

Abstract

Background: The use of polymers in implant dentistry is gaining popularity, as they might have several advantages due to their shock absorption capacity.

Purpose: The aim of this study was to evaluate the performance and fracture strength of three resilient shock-absorbing polymer-based materials as well as the widely used ceramics as one-piece screw-retained implant-supported hybrid-abutment-crowns.

Materials and methods: Forty custom-made CAD/CAM one-piece screw-retained restorations were milled out of 5 different monolithic materials (n = 8); Z: 3Y-TZP zirconia, L: lithium disilicate, P: ceramic-reinforced polyetheretherketone (PEEK), C: nano-hybrid composite resin and E: polymer-infiltrated ceramic-network. Specimens were subjected to dynamic loading for 1,200,000 cycles with integrated thermal cycling. The surviving specimens were subjected to quasi-static loading until failure. Shapiro-Wilk test was used to test for normality, and Levene test was conducted to test the homogeneity of variance. One-way ANOVA test followed by Tukey's post-hoc test were used to detect statistically significant differences between groups.

Results: All specimens withstood 1,200,000 cycles of thermo-dynamic loading with no signs of cracks or screw loosening. The median values of fracture strength varied from a minimum of 670 N for group E to a maximum of 2645 N for group Z.

Conclusions: Fracture strength of screw-retained hybrid-abutment-crowns is influenced by the material used. Zirconia showed superior results. However, its fracture strength was comparable to that of PEEK, which additionally enjoys a shock absorbing property.

Keywords: Abutment; Ceramic; Implant; PEEK; Polymer; Resin; Zirconia.

MeSH terms

  • Bone Screws
  • Ceramics
  • Computer-Aided Design
  • Crowns*
  • Dental Porcelain
  • Dental Restoration Failure
  • Dental Stress Analysis
  • Materials Testing
  • Zirconium*

Substances

  • Dental Porcelain
  • Zirconium