ALL-on-4 Over Denture
Implant dentures are a type of overdenture attached to implants, which differs from a regular denture that rests on the gums. These dentures are used typically when the patient has no remaining teeth in the jaw, but has sufficient bone to support implants. They also have special attachments that snap closed to connect them with the implants. For patients who have difficulty getting a regular lower denture to work for them, these are an ideal solution. Implant dentures are also suitable for upper arch teeth too, however.
The All-on-4 Overdenture
Screw-retained hybrid dentures and hybrid bridges are proven replacements for removable prostheses worn by patients with missing teeth. A custom acrylic framework is fabricated on your master model work and then scanned. The scanned data of the framework and the individual implant platforms are transferred to a design station where the one-piece bar framework is finalized. After design, it is milled from titanium for a precision fit of less than 20 microns. The industry standard screw-retained hybrid denture incorporates this bar into the acrylic processing of the denture tooth setup.
The premium hybrid bridge incorporates shaded gingival tissue and zirconia-based ceramic restorations that are cemented onto the precision-milled titanium bar, making implant dentures a highly esthetic option. Both options offer excellent predictability and function.
Another more affordable, biocompatible option for the patient is the CST or Cable-Stayed Framework, which uses frames manufactured out of compressible hybrid fiber design for optimized physical strength. These give patients the esthetics and comfort of their own dentition. It’s a major evolution in fiber design and application, as well as an ingeniously simple concept for fabricating an implant supported fiber structure for fixed/hybrid dentures, popularized by solutions like the All-on-4™ implant system.
CST® fibers contain elastic properties known as “visco elastic” that resemble acrylic far more than metal. Implant dentures made from visco elastic materials are more likely to warp under stress loads, but they return to their initial shape provided the stress loads don’t exceed specific levels. The primary advantage of visco elasticity is that it lowers peak stress loads by stretching out the load “period”.
Like cable-stayed bridges and reinforced concrete, which take advantage of visco elasticity themselves, the CST® concept results in strong and durable prosthesetic devices. This is partly due to the high degree of compatibility between CST® fibers and the acrylics or composites that are flowed or “processed” around the framework. The strength of the completed prostheses is also affected by the chemical compatibility between the CST® fibers and the acrylic, in that they are chemically bonded.
The addition of glass fibers has consistently shown an increase in the fracture resistance of the dental acrylics used in implant dentures. In one study, the fracture resistance of denture acrylic increased by 280% with the addition of FiBER FORCE® mesh fibers, at a volume of 25% by weight. FiBER FORCE® CST® frameworks processed in acrylic have been shown to resist forces of 400 daN (880 lb.). On a distal extension of 11mm a fracture resistance of 92 daN (202 lb.) has been demonstrated – 200% more than an unreinforced distal extension. As maximum generated posterior intraoral forces – as opposed to functional forces, which are much lower – are generally accepted to be in the region of 50 daN (110 lb.), FiBER FORCE® CST® structures have demonstrated sufficient physical strength to stand up to even the most extreme intra-oral forces.