Scientific article
Open access

Five-year randomized controlled clinical study comparing cemented and screw-retained zirconia-based implant-supported single crowns

Published inClinical oral implants research, vol. 33, no. 5, p. 537-547
Publication date2022-05
First online date2022-03-03

Objectives: To compare screw-retained and cemented all-ceramic implant-supported single crowns regarding biological and technical outcomes over a 5-year observation period.

Materials and methods: In 44 patients, 44 two-piece dental implants were placed in single-tooth gaps in the esthetic zone. Patients randomly received a screw-retained (SR) or cemented (CR) all-ceramic single crown and were then re-examined annually up to 5 years. Outcome measures included: clinical, biological, technical, and radiographic parameters. Data were statistically analyzed with Wilcoxon-Mann-Whitney, Wilcoxon, and Fisher's exact tests.

Results: During the observation period, three patients (6.8%) were loss to follow-up. Eight restorations (18.2%, CI (8.2%, 32.7%)) were lost due to technical (6 patients, 13.6% (CI (5.2%, 27.4%)), 2 CR and 4 SR group, intergroup p = .673; implants still present) or biological complications (2 patients, 4.5% (CI (0.6%, 16.5%)), only CR group, intergroup p = .201, both implants lost). This resulted in a survival rate of 81.2% (CI (65.9%, 90.1%)) on the restorative level (18 SR; 15 CR, 3 lost to follow-up). At the 5-year follow-up, the median marginal bone levels were located slightly apical relative to the implant shoulder with 0.4 mm (0.5; 0.3) (SR) and 0.4 mm (0.8; 0.3) (CR) (intergroup p = .582). Cemented restorations demonstrated a significantly higher biological complication rate (36.8%, SR: 0.0%; intergroup p = .0022), as well as a significantly higher overall complication rate (68.4%, SR: 22.7%, intergroup p = .0049). All other outcomes did not differ significantly between the two groups (p > .05).

Conclusions: All-ceramic single-tooth restorations on two-piece dental implants resulted in a relatively low survival rate. Cemented restorations were associated with a higher biological and overall complication rate than screw-retained restorations.

  • Biologic complications
  • Cemented
  • Ceramic abutments
  • Implant abutments
  • Screw-retained
  • Single crowns
  • Technical complications
  • Zirconia
  • Bone Screws
  • Crowns
  • Dental Abutments
  • Dental Implants
  • Dental Implants, Single-Tooth
  • Dental Porcelain
  • Dental Prosthesis, Implant-Supported
  • Dental Restoration Failure
  • Esthetics, Dental
  • Humans
  • Zirconium
Citation (ISO format)
KRAUS, Riccardo D et al. Five-year randomized controlled clinical study comparing cemented and screw-retained zirconia-based implant-supported single crowns. In: Clinical oral implants research, 2022, vol. 33, n° 5, p. 537–547. doi: 10.1111/clr.13913
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Article (Published version)
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ISSN of the journal0905-7161

Technical informations

Creation11/28/2022 11:13:00 AM
First validation11/28/2022 11:13:00 AM
Update time03/16/2023 9:05:51 AM
Status update03/16/2023 9:05:49 AM
Last indexation02/12/2024 1:44:38 PM
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