Prosthetics is the branch of dentistry which deals with restoring missing teeth. Restoration can be divided into the removable one, which can be put on and taken off by patients themselves, and permanent, which are cemented permanently in patients’ mouths with the aid of special lutting agents.
Removable restorations are dentures. They can complement partial or complete teeth deficiencies. Both complete dentures, i.e. worn by patients who have no teeth, and partial dentures are made of acrylic. They can be replaced by skeleton dentures, which are more stable, cover smaller area, and are generally accepted more by patients. Skeleton dentures can be made of metal or acetal. Acetal is special elastic resin, which matches the patient’s teeth colour and is particularly recommended for patients allergic to metal. We usually make combine dentures, with a metal skeleton and acetal clasps, rather than whole acetal dentures.
If the conditions in the patient’s oral cavity are appropriate, in order to improve skeleton dentures’ maintenance and achieve better aesthetic effect, combine work is done. Combine work includes permanent prosthetic restoration (crowns and/or bridges), connected with the movable part (so called a skeletal denture on denture locks) with the aid of precise retention elements, i.e. locks, bars, ball denture locks and bolts.
The biggest problem for patients wearing complete dentures is the fact that they tend not to remain stably on their gingiva. The problem concerns especially lower dentures. They can be stabilized with the use of implants with dentures locks, which connect them with a denture. In case of upper dentures, it is possible to limit the plate’s coverage of the patient’s palate, making the denture more comfortable to wear. At our dental office we use implants of a Swiss company Straumann and the system of a so called locator.
Permanent restorations include: crowns, bridges, facings, crown-root input, crown on-lay, and endocrowns which have become more and more popular recently.
Prosthetic crown are made in case of considerable destruction of one’s own tooth; when it needs to be rebuilt in respect of its aesthetic and functional roles. A crown covers the whole tooth, and can be made on a metal or gold base. Next, the base is coated with porcelain.
Another kind of base is zircon. It is also coated with porcelain. In case of a single crown, sometimes only porcelain is used, without the base. A crowns like this is called an all-ceramic crown. It is very aesthetic, resilient and safe for people allergic to metal. It perfectly imitates the patient’s own teeth and cannot be discriminated easily.
Crown are also placed in patients who have already had implanted teeth.
Here, both metal connectors and classic metal-porcelain crowns can be used. Also more aesthetic work , especially recommended for front teeth, can be done: all-ceramic crown with ceramic connector.
In case of a complete destruction of a dental crown, when only the root exists (and there is no place to attach the crown), crown-root inlays need to be made. These are restorative pins fixed permanently to the tooth’s root, above which a miniature tooth protrudes. And only here a crown can be cemented. It has become more and more common that inlays are made of fiberglass, which is very elastic and connects well with the tooth tissues.
An endocrown, a novelty in recent times, has itself the retention which is necessary to keep a crown in a tooth. Applied in dead teeth, endocrowns manage without pin. They are made of porcelain or composite and are very aesthetic. Thanks to more and more modern connecting systems endocrowns stick to the tooth very well, too.
Also veneers, i.e. thin overlays, are made of porcelain. Veneers are cemented to the external surface of front teeth in order to improve their appearance and shape. Teeth do not require a lot of preparation- taking 0,5-1mm of enamel from the top is enough. In consequence, the procedure is not invasive and the effect is spectacular (Hollywood smile).
A crown inlay (onlay, overlay) is a filling made of porcelain or strengthened composite, made by a dentist technician in his /her office. A crown inlay is similar to a filling, but is stronger and abrades more slowly. It is recommended for patients whose fillings tend to fall out or when it is necessary to make a superstructure of many teeth, because of e.g. considerable teeth attrition.
Prosthetic bridges, which let reconstruct missing teeth, use the remaining teeth. A patient’s own teeth, adjacent to the gap after a missing tooth, are called abutment teeth. Before the crown imitating the missing tooth is placed between them, abutment teeth need to be grinded and crowns must be put on them. Bridges, similarly to single crowns are made of metal covered with porcelain or ceramic.
In particular cases (for instance, after losing single teeth due to paradental diseases) in order to complete the missing teeth, it is possible to use a tape made of fiberglass. Splinting the remaining teeth, the missing tooth is placed. Then, it is not necessary to grind the patient’s own teeth- only a little groove is made just to hide the tape.
At our dental office we are willing to make also adhesive bridges, which has become more and more popular. The great advantage of adhesive bridges is the fact that adjacent teeth do not need to be grinded. They are only brushed up gently, like while putting an ordinary filling. Still, only single teeth loses can be completed with adhesive bridges.