Influence of monolithic restorative materials on the implant-abutment interface of hybrid abutment crowns: An in vitro investigation

J Prosthodont Res. 2023 Jul 31;67(3):450-459. doi: 10.2186/jpr.JPR_D_22_00115. Epub 2022 Dec 15.

Abstract

Purpose This in vitro study aimed to investigate the long-term performance, stability, and fracture mode of monolithic hybrid abutment crowns, and the effect of different materials on the implant-abutment interface (IAI).Methods Eighty monolithic hybrid abutment crowns luted on titanium bases were manufactured from 3Y-TZP zirconia (ZY3), "Gradient Technology" zirconia (ZY35), 5Y-TZP zirconia (ZY5), lithium disilicate ceramic (LDS), zirconia-reinforced lithium silicate ceramic (ZLS), polymer-infiltrated ceramic network (MHY), polymethylmethacrylate (PMA), and 3D-printed hybrid composite (PHC) (n = 10 for each material). Eighty implants (Camlog Progressive-Line, diameter: 3.8 mm) were embedded in accordance with ISO standard 14801, and crowns were mounted. After artificial aging (1.2 × 106 cycles, 50 N, thermocycling), intact specimens were loaded 30° off-axis in a universal testing machine until failure.Results Seven specimens in the PHC group failed during artificial aging, and all the others survived. There were two subgroups based on the one-way analysis of variance and Dunnett's test (P < 0.05) of the mean fracture load values. The first comprised Z3Y, ZY35, Z5Y, and LDS, with mean fracture loads between 499.4 and 529.7 N, while the second included ZLS, MHY, and PMA, with values in the 346.2-416.0 N range. ZY3, ZY35, ZY5, and LDS exhibited irreversible, visible deformations of the implant shoulders with varying dimensions after load-to-fracture tests.Conclusions Crowns made of LDS, ZLS, MHY, and PMA may act as potential stress breakers, and prevent possible deformation at IAIs. Further clinical studies need to assess if these materials also withstand relevant loads in-vivo.

Keywords: CAD-CAM materials; Fatigue testing; Hybrid abutment crowns; Implant-abutment interface; Single implants.

MeSH terms

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

Substances

  • zirconium oxide
  • Dental Porcelain
  • Zirconium