Removable restorations are a subcategory of prosthetics. Various versions of partial restorations supplement existing teeth and/or implants. Full restorations (full/complete dentures) replace all the teeth in an edentulous jaw (the only prosthetic alternative not involving implants).
A differentiation is made between less expensive, purely removable restorations (this includes full dentures and clasped dentures retained on natural teeth) and more expensive fixed-removable dentures. With more expensive restorations the removable section is anchored using retentive and connector elements (possible options are clasps, attachments, telescope crowns, press-stud systems, magnets etc.) on the periodontally-borne, fixed section of the restoration (mainly in the form of crowns or bridges on teeth and implants).
Telescopic denture (wax try-in, stone model)
An overdenture completely covers all connectors and corresponds to a full denture.
Generally, removable restorations cover segments which are extended to a greater or lesser extent, supported by and cover the load-bearing mucosa. During fabrication, the aim is to achieve uniform fit of the removable restoration base on the jaw using special impression materials and procedures. If the resilience of the mucosa is exceeded or if the removable restoration is subjected to repeated rubbing movements, pressure spots may quickly occur. After months and years the bony denture-bearing area resorbs individually by varying degrees (physiological and pressure atrophy). Congruency can be restored by relining the denture base.
The area of the removable restoration that covers the hard palate in the upper jaw is referred to as the palatal plate (fabricated from acrylic or metal) and a section on the edentulous alveolar ridge is referred to as the saddle. Removable restoration saddles are often connected by a metal base (frequently fabricated using CrCo), in the upper jaw possibly using a large connector (transverse connector) and in the lower jaw using a lingual bar. Removable restorations can, however, also be fabricated completely without metal.
Clasped CoCr denture on stone model
Missing teeth are mostly replaced on saddles by prefabricated denture teeth made from acrylic, less commonly (historically more frequently) also by prefabricated porcelain teeth. In contrast, removable bridges (mainly supported by telescope crowns) replace teeth with solid or veneered pontics and function entirely or as far as possible without mucosal coverage.
Restorations, which are fixed for the patient (possibly screw-retained or semi-permanently cemented), but are designed to be removable by the dentist, are called "operator-removable".
Removable restorations - unlike fixed restorations - allow extraoral care and repair measures. Control and hygiene of the residual teeth are also facilitated. In many cases removable restorations can be extended if load-bearing abutment teeth are lost and a remake is often unnecessary.
With removable restorations placing implants to increase the number of abutments can contribute to firmer, more stable retention and easing of the stress on residual natural teeth.
If a removable restoration is only to be worn temporarily, e.g. for testing a new occlusal relationship or bridging the period required for fabrication of the definitive restoration or other treatment, it is called a temporary restoration. This often involves a simple acrylic denture, with bent wire clasps if necessary. Removable restorations, fitted immediately following surgery (implant placement or extraction), are called immediate restorations.
If other anatomical structures are also replaced by removable restorations in addition to missing teeth, these are referred to as maxillofacial appliance.