Overdenture Maintenance — Service and Matrix Replacement

Overdentures are a partial solution—neither fixed implant prostheses nor conventional removable dentures. Patients must understand that this type of prosthesis requires systematic maintenance and component replacement. The laboratory must be prepared to perform this service promptly, without delays.

What is an Overdenture?

An overdenture is a removable prosthesis supported by implants. It relies on implants via retentive matrices (locator, O-ring, bar), but the patient can remove it. Benefits: cheaper than a fixed prosthesis on multiple implants, easier to clean.

Drawbacks: requires service, matrix replacement, less stability than a fixed prosthesis.

Maintenance Schedule

Period	Action	Significance
24-48 h after placement	Occlusion check	Matrices may be too loose—requires adjustment
1 month	First matrix replacement	Patient "learns" to use them experimentally—matrices may already be worn
3 months	Retention check	Are the matrices still sufficiently retentive?
Every 6-12 months	Matrix replacement	Standard—matrices wear out with repeated insertion/removal
Annual check-up	Overall prosthesis evaluation	Does it require relining, repair, or partial matrix replacement?

The patient must be trained in correct insertion and removal. Careless maneuvers shorten matrix lifespan.

Common Problems and Solutions

Matrices too loose or too tight — the first replacement may be needed within a few days. The manufacturer offers matrices with various retention levels (light, regular, heavy).

Undercut reline — after a few months, the palatal foundation changes (bone resorption). This requires relining the undercut of the denture. Complimentary — part of standard service.

Fracture of the attachment housing — the patient applies too much pressure or manipulates incorrectly. Connector replacement, new matrices.

Patient cannot manage manipulation — some patients (motor skill issues, arthritis) have difficulty with insertion/removal. In such cases, it is better to consider a fixed prosthesis.

Materials and Components

Standard overdenture components (deltalabs.):

Locator matrices — most common, universal for most implants
O-ring systems — less popular, require precisely matched patrix
Bar system — for multiple implants, more complex

Matrix replacement is a 30-minute procedure, costing 200-400 PLN per patient (depending on the number of implants).

Patient Education

The patient must know:

How to insert and remove — demonstration before delivering the prosthesis, educational materials
Service is mandatory — overdentures are not "set it and forget it"
Cost of service — matrix replacement every 6-12 months
Alternative — if the patient does not want service, it is better to consider a fixed prosthesis