Clinical assessment of different implant-supported esthetic crown systems fabricated with semi-digital workflow: Two-year prospective study

J Esthet Restor Dent. 2022 Dec;34(8):1247-1262. doi: 10.1111/jerd.12961. Epub 2022 Sep 19.


Objective: To assess the clinical outcome of three esthetic implant-supported crown systems fabricated with semi-digital workflow and their influence on the clinical outcome of dental implants.

Material and methods: A total of 30 participants had received dental implants restoring missing maxillary first/second premolars. After 6 weeks, customized zirconia abutments were early loaded. Two months later, the definitive crowns were fabricated using semi-digital workflow and cemented. According to the crown material, 3 groups were randomly allocated; group (Z): ultrahigh-translucent monolithic zirconia, group (C): resin-matrix ceramic and group (P): polyetherketoneketone veneered with light-cured composite resin. Clinical outcomes including the survival and success rates were evaluated at baseline, 6, 12, 18, and 24 months.

Results: The survival rate for all studied groups was 100%, while their success rate was 100% for group (Z) and 90% for group (C) and group (P). Based on the functional implant prosthodontic score, a statistically significant difference was detected between group (Z) and group (P) (p < 0.001) as well as between group (C) and group (P) (p = 0.01).

Conclusions: The zirconia group had the most favorable clinical behavior, while the polyetherketoneketone had the least. All crown systems had comparable success rates with similar values of the peri-implant marginal bone loss.

Clinical significance: Using semi-digital workflow, ultrahigh-translucent monolithic zirconia, resin-matrix ceramic and polyetherketoneketone veneered with light-cured composite resin can be considered as favorable implant-supported crowns. The implant-supported crown system based on polyetherketoneketone veneered with light-cured composite resin is counted as a promising esthetic and restorative option.

Keywords: PEKK; dental implants; digital workflow; hybrid abutments; resin-matrix ceramic; zirconia.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Ceramics
  • Composite Resins
  • Computer-Aided Design
  • Crowns
  • Dental Abutments
  • Dental Implants*
  • Dental Prosthesis, Implant-Supported
  • Dental Restoration Failure
  • Esthetics, Dental
  • Humans
  • Prospective Studies
  • Workflow
  • Zirconium


  • Composite Resins
  • Dental Implants
  • polyetherketoneketone
  • Zirconium
  • zirconium oxide