Retrospective Database Study: Influence of Post-endodontic Restoration Placement on Survival of Root Canal-treated Teeth

January 24, 2026 updated by: Philipp Kanzow, Prof. Dr. med. dent., Dr. rer. medic., University of Göttingen

Influence of the Timing of Post-endodontic Restoration Placement on the Survival of Root Canal-treated Teeth

The aim of this study is to assess the influence (i.e. type and timing) of post-endodontic restorations on the survival of root canal-treated teeth and to determine the influence of patient-, tooth-, treatment-, and restoration-specific parameters on longevity.

Patients who received a root-canal treatment between 1998 and 1999 with subsequent placement of an indirect restoration (e.g. crown, partial crown) will be retrospectively analyzed. Patient-, tooth-, treatment-, and restoration-specific parameters will be obtained from digital and paper-based dental records.

Survival and success of the root-canal treatments will be assessed using Kaplan-Meier statistics. Mean annual failure rates (mAFR) and median survival time will be calculated (Kaplan-Meier statistics). Potential predictive factors will be tested using log-rank tests and multi-variate Cox-regression analysis.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Actual)

541

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Germany
    • Lower Saxony
      • Göttingen, Lower Saxony, Germany, 37075
        • University Medical Center Göttingen, Dept. of Preventive Dentistry, Periodontology and Cariology

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients who received a root-canal treatment followed by the placement of an indirect post-endodontic restoration (e.g. partial crowns, crowns) within the Department of Preventive Dentistry, Periodontology and Cariology between 1998 and 1999.

Description

Inclusion Criteria:

  • Patients who received a root-canal treatment followed by the placement of an indirect post-endodontic restoration (e.g. partial crowns, crowns) within the Department of Preventive Dentistry, Periodontology and Cariology between 1998 and 1999.

Exclusion Criteria:

  • None.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Indirect post-endodontic restorations
Indirect post-endodontic restorations (e.g. crown, partial crown).
Other: No patient treatment is associated with the study
No patient treatment is associated with the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Success of endodontic treatment
Time Frame: 1998-2023
Success is defined as the time-interval without a subsequent endodontic re-intervention or extraction of the tooth.
1998-2023

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Survival of the tooth
Time Frame: 1998-2023
Survival of the tooth is defined as the time-interval without extraction of the tooth.
1998-2023

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Göttingen

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2024

Primary Completion (Actual)

June 1, 2025

Study Completion (Actual)

June 1, 2025

Study Registration Dates

First Submitted

May 28, 2024

First Submitted That Met QC Criteria

May 28, 2024

First Posted (Actual)

June 4, 2024

Study Record Updates

Last Update Posted (Actual)

January 27, 2026

Last Update Submitted That Met QC Criteria

January 24, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • Timing-post-endodontic
  • 20/2/20 (Other Identifier: Local Ethics Commission)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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