Implant-supported Maxillary Overdentures; a 15-years Evaluation
116 participantsStarted 2026-05-01
Plain-language summary
* Background Patients experiencing problems with their conventional maxillary denture can benefit from implant- retained overdentures. Bar-retained implant overdentures can be supported by 4 or 6 implants, splinted by a bar. Evidence on maxillary implant overdentures has been mostly short to medium term, non-comparing or retrospective. Even more, 15-years data of comparative studies are lacking. It is important to evaluate treatment outcomes, such as implant survival, peri-implant bone changes and patient satisfaction at the long-term.
* Main research question The aim of this 15-years study is to evaluate a patient group treated 15 years ago in a prospective study with a maxillary overdenture on 4 or 6 implants in an edentulous maxilla. The primary objective of the study is to analyze marginal bone level changes by radiological assessments at 15-years follow-up. Secondary objectives are implant and overdenture survival, condition of peri- implant mucosa and patients' satisfaction.
* Design (including population, confounders/outcomes) The study design is an observational study of a group of patients which were treated 15 years ago with dental implants and an overdenture in the maxilla because of problems with retention and stability with their conventional denture. Outcomes: primary outcome is the change in marginal peri-implant bone level 15 years after placing the overdenture. Secondary outcome measures will be implant and overdenture survival, peri-implant mucosa health and patients' satisfaction using a questionnaire.
* Expected results Stable peri-implant bone levels, high implant and overdenture survival rate and satisfied patients.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Fully edentulous patients or patients with an overdenture in the mandible, who were referred to the Department of Oral and Maxillofacial Surgery (University Medical Center Groningen, the Netherlands) 15 years ago, because they suffered from a lack of retention and stability of the upper denture;
At the time of treatment:
* Edentulous in the maxilla for at least one year;
* Sufficient bone volume in height in the anterior or posterior region of the maxilla to place the implants;
* The patient was 18 years or older;
* Sufficient interocclusal space for placement of an overdenture with attachment system;
* The patient was capable of understanding and giving informed consent.
Exclusion criteria at the time of treatment:
* Patients with American Society of Anesthesiologists score (ASA score) ≥ III;
* Patients who were smoking;
* Patients with a history of radiotherapy in the head and neck region;
* Patients with a history of pre-prosthetic surgery or previous implant placement in the maxilla.
Exclusion Criteria:
None
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Change in peri-implant marginal bone level
Timeframe: Through study completion, an average of 15 years