Variables for Long-term Success in Implant Dentistry

January 21, 2026 updated by: University of Bern

Variables for Long-term Success in Implant Dentistry: A Retrospective Cross-sectional Study With a 25 Year Follow-up or More

The aims of the present retrospective 25-year study of a sample of 459 patients with 753 sandblasted and acid-etched (SLA) titanium oral implants are:

  • to assess the clinical parameters at SLA implants after 25 years in function
  • to assess the crestal bone levels at SLA implants after 25 years in function
  • to assess and compare the microbiological conditions at SLA implants and their adjacent teeth after 25 years of function
  • to assess the periodontal conditions in patients having received SLA implants 25 years ago
  • to establish a baseline data set for future prospective studies on patients having received SLA implants 25 years ago
  • to assess the incidence rates of biological, technical, traumatic failures / complications with SLA implants
  • to assess the incidence rates of technical failures / complications with prosthetic components on SLA implants
  • to assess the incidence rates of biological, technical, mechanical, esthetic failures / complications with prosthetic reconstructions on SLA implants
  • to find potential risk factors for biological failures / complications with SLA implants; i.e. patients having lost their teeth due to different reasons (e.g. partial anodontia, caries, periodontitis, endodontic failure, trauma, vertical root fracture), (ii) to calculate the success rates using different thresholds set as success criteria, (iii) to evaluate the influence of medical conditions and tobacco smoking on the long-term prognosis of titanium oral implants, and (iv) to assess the frequency and quality of maintenance
  • to find potential risk factors for mechanical, technical, esthetic failures/complications with reconstructions seated on SLA implants
  • to assess the treatment need and utility of implant therapy after 25 years in patients having received SLA implants

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Specific aims

The aims of the present retrospective 25-year study of a sample of 459 patients with 753 sandblasted and acid-etched (SLA) titanium oral implants are:

  • to assess the clinical parameters at SLA implants after 25 years in function
  • to assess the crestal bone levels at SLA implants after 25 years in function
  • to assess and compare the microbiological conditions at SLA implants and their adjacent teeth after 25 years of function
  • to assess the periodontal conditions in patients having received SLA implants 25 years ago
  • to establish a baseline data set for future prospective studies on patients having received SLA implants 25 years ago
  • to assess the incidence rates of biological, technical, traumatic failures / complications with SLA implants
  • to assess the incidence rates of technical failures / complications with prosthetic components on SLA implants
  • to assess the incidence rates of biological, technical, mechanical, esthetic failures / complications with prosthetic reconstructions on SLA implants
  • to find potential risk factors for biological failures / complications with SLA implants; i.e. patients having lost their teeth due to different reasons (e.g. partial anodontia, caries, periodontitis, endodontic failure, trauma, vertical root fracture), (ii) to calculate the success rates using different thresholds set as success criteria, (iii) to evaluate the influence of medical conditions and tobacco smoking on the long-term prognosis of titanium oral implants, and (iv) to assess the frequency and quality of maintenance
  • to find potential risk factors for mechanical, technical, esthetic failures/complications with reconstructions seated on SLA implants
  • to assess the treatment need and utility of implant therapy after 25 years in patients having received SLA implants

Material and methods Out of the pool of patients from the Departments of Oral Surgery and Periodontology and Fixed Prosthodontics at the University of Bern, Switzerland, all patients having received at least one dental implant will be recruited for a comprehensive evaluation 25 years after implant installation and delivery of the reconstruction. The patients had been treated according to a comprehensive treatment strategy prior to the installation of implants and incorporation of reconstructions. All patients were offered maintenance care that was provided either in the School of Dental Medicine, University of Bern, Switzerland, or in the dental practices of the referring dentists at intervals between 3 and 6 months.

All the implants installed were solid screws (SS) with a diameter of 3.3, 4.1 or 4.8 mm, a length between 6-14 mm and a sandblasted and acid-etched surface (SLA) (Straumann® Dental Implant System, Institute Straumann AG, Basel, Switzerland). The implants were placed according to the manufacturer's instructions. The reconstructions were either cemented or screw-retained and consisted of single-unit crowns (SCs) or short-span fixed dental prostheses (FDPs) with or without cantilever extension(s).

Study Type

Observational

Enrollment (Actual)

160

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

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

Yes

Sampling Method

Non-Probability Sample

Study Population

Out of the pool of patients from the Departments of Oral Surgery and Periodontology and Fixed Prosthodontics at the University of Bern, Switzerland, all patients having received at least one dental implant will be recruited for a comprehensive evaluation 25 years after implant installation and delivery of the reconstruction. The patients had been treated according to a comprehensive treatment strategy prior to the installation of implants and incorporation of reconstructions. All patients were offered maintenance care that was provided either in the School of Dental Medicine, University of Bern, Switzerland, or in the dental practices of the referring dentists at intervals between 3 and 6 months.

All the implants installed were solid screws (SS) with a diameter of 3.3, 4.1 or 4.8 mm, a length between 6-14 mm and a sandblasted and acid-etched surface (SLA) (Straumann® Dental Implant System, Institute Straumann AG, Basel, Switzerland).

Description

Inclusion Criteria:

All patients rehabilitated with oral dental implants supporting fixed partial dental prostheses and followed up for at least 20-years.

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
Partial edentulous patients rehabilitated with at least one dental implant
Partial edentulous patients rehabilitated with at least one dental implant in function for at least 20-years
Other: Oral rehabilitation with dental implants
Patients rehabilitated with implant-supported fixed partial dental prostheses

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Implant survival rate
Time Frame: 25 years
percentage of implants in-situ
25 years

Collaborators and Investigators

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

Sponsor

University of Bern

Investigators

  • Study Chair: Martin Schimmel, University of Bern

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

September 9, 2024

Primary Completion (Actual)

July 30, 2025

Study Completion (Actual)

December 31, 2025

Study Registration Dates

First Submitted

September 5, 2024

First Submitted That Met QC Criteria

September 12, 2024

First Posted (Actual)

September 19, 2024

Study Record Updates

Last Update Posted (Actual)

January 23, 2026

Last Update Submitted That Met QC Criteria

January 21, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2023-02279
  • ITI n 1574_2021 (Other Grant/Funding Number: International Team for Implantology)

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

product manufactured in and exported from the U.S.

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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