Function, esthetics, and stability. Those are the three key words when fabricating an implant retained overdenture. And when it comes to patient satisfaction, a stable and comfortable fit is undoubtedly the decisive factor. With multiple implants, the position of the bar with respect to the tooth arrangement is extremely important to avoid tilting movements. The case study presented here is based on a prosthetic concept which fully considers this principle. The concept has already been successfully applied for many years around the world. Its simplicity and flexibility allow its use in widely divergent situations.

When planning a bar construction, the position of the dental arch–and not of the implants–is the point of departure. In the anterior area as well as premolar and molar region, the bar is placed underneath the teeth. Moreover, it is extended in dorsal direction while reducing the dental arch. Under ideal conditions, the dorsal bar extension coincides with the terminal prosthetic element.
What goes for a normal overdenture also goes here. This means that the retromolar pad and the maxillary tuberosity must always be covered. The palate usually remains free.

The Green Tangent lines at the implants form a plane through which a blue dotted centre line runs.

The blue dotted centre line intersects the vertical center line in Point A1. The vertical center line is at right angles to the hinge axis.

The distance between A2 and A3 is approximately half as much as the distance between A1 and A2.

A line through Point A3 runs parallel to the hinge axis. The ridge intersections indicate the maximum extensions. Up to these points, the prosthesis can be supported by the bar surface.

On this case, the stability of the prosthesis is guaranteed by (tripod) three parts: 1) the two distal attachments, 2) the anterior Hader bar attachment, and 3) the dental arch which is almost completely supported by the bar.
For maxillary constructions, the palate remains free. The extensions of the acrylic resin into the vestibule considerably improves the facial physiognomy–which is often impossible with bridges. The fact that the prosthesis is removable offers advantages such as oral hygiene and servicing.

The implant retained overdenture is an excellent alternative for fixed or screwed bridges.