These are partial dentures made from metal and plastic. The skeleton (major connector) and the hooks, used to hold the denture, are made from metal and the visible parts and the teeth – from plastic. Plastic-only dentures have a denture plate, which covers the entire palate of the upper jaw or the area under the tongue of the lower jaw, causing discomfort, a feeling of a foreign body in the mouth, reduction of the sensation of taste, hot and cold. Cast partial dentures have this plate replaced by a metal connector. Thus, the denture skeleton is extremely strong. This allows reduction in size, which ensures comfort and reduces the feeling of the denture being too big. The sense of taste and warmth of the food are close to normal. Patients get used to this type of dentures very quickly, but they are difficult to manufacture and cost more. They can be used in all teeth defects, in which a sufficient number of healthy teeth is available to bear the denture. This is necessary because they are very stable in the mouth, and may have only very minimal movements. These movements are ensured by the production of individually cast metal hooks, which are consistent with the shape and characteristics of the teeth of the individual.
The planning of cast partial dentures is a complicated process and must meet many requirements – correct transmission of the masticatory pressure on the available teeth, and restoration of optimum speech and aesthetics.
The manufacturing stages of this type of dentures are similar to those of the plastic-only dentures, so only the important points from their manufacture are described here briefly.
Gypsum models of the jaws are molded by the dental technician and placed in the proper ratio (to achieve central occlusion). At this stage individual impression spoons are made and the main analysis of the denture is performed. The direction of insertion and removal of the denture, the supporting teeth, their retention areas that will serve as a retention hooks, and the type are also decided here.
Occlusal templates with shafts are manufacture as well.
The hooks are also tested whether they fit tightly the supporting teeth and hold the denture well in place. The height and occlusion is determined using the templates. In the dental laboratory the artificial teeth are added and the final denture is made.
Fourth visit – The completed denture is placed in the mouth. Only the chewing surfaces of the teeth can be corrected if needed but not the metal skeleton. The dentist explains to the patient how to place and remove the denture, store and clean it, and how to maintain good oral hygiene.
Adaptation of the patient to this type of denture is quicker – from several days to two weeks. They are easily removed and placed in the mouth and are much more comfortable and stable when chewing. Qualitatively planned and made, they are a guarantee for achieving great nutrition, aesthetics and a lack of speech issues.