Computer Aided Design ‚Äì a software that renders the geometrical shape of an object. It wasn‚Äôt under recently, CAD has become commercially available for fabrication of complete dentures through the system called AvaDent digital dentures. It allows for impression, interocclusal and records + tooth selection to be completed in one appointment. During the second appointment, the CAD technology will fabricate the dentures. Because this has now become commercially available, it will be possible to scan the denture base morphology and toorh positions that are recorded using this technique and move the data to a virtual tooth arrangement program.
Fabrication of complete dentures usually involves 5-step appointments
1.Create preliminary impressions
Customization of stock trays will happen during the first appointment. This procedure involves fabricating a putty cast that is form by pressing mixed poly (vinyl siloxane)¬† putty into the intaglio surface of the existing dentures. The tray is then softened once it‚Äôs been¬† immersed in water bath for about one minute with a set temperature of 80 degrees Celsius. This is then adapted to the putty cast by pressing the material into contact with the cast and stretches the material to cover the area required. Once the trays have been adapted to the putty cast, the patient tries it on to see if there are areas that need adjustments.
2. Create final impressions
After the impression trays have been customized and confirm that the appropriate areas are covered and adjust according to the patient‚Äôs mouth. The appropriate adhesive will then be applied; the trays are then placed in the patient‚Äôs mouth and positioned so the trays are not pressed into contact with the soft tissue, therefore leaving enough room for the border boulding and wash impression material.
3. Record jaw relation
This denture technique uses an AMD device or also known as Anatomical Measuring Device that can be adjusted to the desired dimension of the patient‚Äôs occlusal vertical and then used to maintain the dimension while centric relation is being recorded. The occlusal vertical dimension is then determined. If the existing dentures provide an appropriate occlusal vertical size, they can then be used to record the distance between the face marks when dentures are in close contact If not, the conventional methods should be used in order to figure out the desired size. The rest of the vertical dimensions, tonicity of the musculature, facial proportions, and bio feedback can them be used to confirm the appropriate occlusal vertical dimension. The adjustable screw in the maxillary tray will then be turned clockwise to extend the stylus do that it comes in contact with the mandibular tracing plate at the appropriate vertical measurement. Once the right vertical measurements has been set, the screw in the maxillary AMD is adjusted and used to expand and withdraw the upper lip support so it give enough lip support. The patient is then given a chance to evaluate the adjustments by inspecting his/her lip in front of the mirror.
4. Placement of the final complete dentures
The post-placement adjustments of the final dentures are similar to the placement of conventional dentures. The denture base is made out of a pink traditional resin material, therefore, it can be picked intraorally using conventional techniques.