Removable prosthodontics uses different types of removable partial and complete dentures including cast metal dentures with precision attachments which are close to fixed bridges as far as aesthetics and comfort is concerned.
This type of prosthetic treatment with removable dentures is used in cases when there are not enough teeth on both sides of the area with missing teeth or when almost all or all teeth are missing. In such cases a dental bridge is impossible because it requires at least one tooth on both sides of the missing teeth area as supporters. Partial removable dentures are attached to the rest of the teeth by clasps or special precision attachments (mechanical joints, ball and bar attachments, telescopic crowns, etc.) The stability of complete dentures and overdentures is achieved by soft tissues of the bearing area and/or dental implants.
The advantages of removable dentures are improved chewing ability, aesthetic appearance and speech especially in cases with missing front teeth. Last but not least, dentures improve self-esteem and quality of life.
Partial removable dentures
Partial removable acrylic dentures
Partial removable acrylic/ plastic dentures use different types of clasps on the natural abutment teeth for support and retention. They are relatively cheap and quick option for replacement of missing teeth. The main problem is that such kind of dentures are not so stable and they traumatize the abutment teeth and oral mucosa. That’s why they are recommended as temporary treatment method until other permanent prosthetic treatment is done.
Before- missing teeth in lower jaw
Partial removable acrylic dentures with wire clasps
Partial removable acrylic denture with wire clasps in lower jaw
According to the material, partial dentures could be made of rigid plastics- acrylics, relined with soft plastic, elastic dentures, etc.
Cast metal partial removable dentures
Cast metal framework is used in this type of partial dentures. This makes the denture thinner and stronger than a regular acrylic denture. Clasps could be made of metal or other aesthetic material. Comfort of the patient is increased, speech is improved because palate and tongue are not covered by acrylics, sense of taste is better. Such dentures are almost immobile during chewing.
The abutment teeth that support and hold the denture in place must be with healthy periodontal tissues. This means no gum inflammation, bleeding, gum recession or mobility. The reason is the abutment teeth are overloaded by the clasps of the dentures and if they are with periodontal disease they will become mobile very fast and would be extracted. If the clasps are made of metal and they are located in the visible area, aesthetics is decreased.
It is a combination of a fixed bridge and a removable cast metal partial denture which are connected by precision attachments. Precision attachments provide greater strength, comfort and aesthetics to the patient. These attachments could be mechanical joints, bar attachemnts, ball attachments, locks, telescopes, etc.
Difference between cast metal dentures with metal clasps and those with precision attachments is that cast metal dentures are much more aesthetic because the precision attachments are hidden between the fixed bridge and removable partial denture. Combined prosthetic approach provides a long-lasting result which depends on excellent oral hygiene and regular recall visits for prophylaxis.
Cast metal dentures with mechanical joints
The abutment teeth (at least two on each side) are treated with block crowns (two connected crowns) or a bridge. The mechanical joints are fixed to the crowns or the bridge. The denture is placed over the mechanical joints which makes the denture very stable and almost immobile during function. Such kind of dentures are extremely aesthetic because the precision attachments (mechanical joints) are hidden. It is important for the long-term result that the chewing pressure and forces are transmitted mainly trough the abutment teeth and less trough the oral mucosa and underlying bone.
Upper metal-ceramic bridge with precision attachments
Cast metal dentures with precision attachments
Upper metal ceramic bridge and cast metal denture, connected with precision attachments
Lower metal-ceramic bridge with precision attachments
Cast metal dentures with precision attachments (inner surface)
Lower metal ceramic bridge and cast metal denture, connected with precision attachments
Cast metal dentures with bar attachments
The abutment teeth which must be periodontally healthy ( without mobility) are prepared for full crowns, connected with a bar attachment. The dentures are very comfortable because the metal frameworks are very thin and the hard palate of the upper jaw and sublingual area of the lower jaw are free, the chewing pressure is transmitted trough abutment teeth mainly.
A metal-ceramic bridge with a bar attachment and two crowns with precision attachment
Cast metal partial denture with bar attachment
Lower cast metal denture with bar attachment
Overdentures look like complete dentures outside but they are supported by specially treated abutment teeth which are hidden under the overdentures. In this way the overdentures are much more stable and comfortable for the patient but it is absolutely necessary to have at least one abutment tooth on each side. Other option is to use dental implants instead of natural abutment teeth.
Before- upper jaw
Ball attachments on two teeth in upper jaw
After- upper overdenture
Before- lower jaw
Ball attachments on two teeth in lower jaw
After- lower overdenture
Complete dentures are used when all the teeth are missing. The complete edentulism (lack of natural teeth) and bone loss lead to serious speech and eating difficulties as well as changes in the patient’s face.
The main task of the prosthetic treatment is to restore the correct bite, improvement of chewing function and speech, aesthetic appearance and self-esteem of the patient.
Upper complete denture relies on vacuum effect for retention. Providing stability of the lower complete denture is much more difficult or impossible due to tongue movement and smaller bearing area which favor the displacement of the lower denture during function. Adaptation to complete dentures takes time and requires patience of the patient. But there is always another modern option- comfortable and stable overdentures over dental implants.
A modern alternative to the removable dentures for replacement of missing teeth are all types of crowns and fixed bridges over dental implants.