A full denture replaces all the teeth on a given arch, upper or lower. It is supported by what is known as the edentulous (free of teeth) ridge which is the remaining jaw bone, covered by gum, that is left after all teeth have been extracted. A full denture consists of a base made from pink acrylic to resemble gum tissue and acrylic denture teeth in various shades to match the enamel of natural teeth. Dr. McArdle does not use porcelain denture teeth because studies have shown that their extreme hardness and lack of "give" transmits chewing forces more fully to your underlying ridges, causing them to shrink at a greater than rate with dentures using acrylic teeth. The shape and shade of the denture teeth are selected to match any remaining natural teeth on the opposing arch and their alignment is determined when a bite is taken during denture fabrication. If a patient has no natural teeth and will be wearing full dentures on both arches, the shade of the denture teeth can be any one the patient desires. The base is made to fit the edentulous ridge by means of impressions being taken of the patient along with the bite. As the ridge gradually shrinks (anywhere from 0.25%-1% per year on average) over time, a new impression will be needed on occasion to reline the denture. Edentulous ridges shrink much more rapidly over the first few months after immediate dentures have been placed. An immediate denture is one that is inserted directly after any and all of the natural teeth on a given arch have been extracted. This is due to the post-surgical healing process that usually lasts about three to four months. Immediate dentures need to be relined at this point in most cases.

A partial denture replaces all missing teeth on a given arch.

A removable partial denture (bridgework is sometimes called a fixed partial denture) replaces any missing teeth on a given arch that has natural teeth remaining. There are two types of partial dentures, cast and acrylic. A cast partial denture includes a cast metal framework (hence the name) along with base acrylic and denture teeth, like a full denture. The metal framework connects to the remaining natural teeth with arms or hooks called clasps that lock into inherent and fabricated undercuts in those natural teeth. This tends to make partial dentures more stable than full dentures, especially on the lower arch. The base acrylic of a cast partial denture sits on the edentulous areas of the arch with the framework imbedded in it and holds the partial's denture teeth. An acrylic partial denture contains no metal framework. It connects with the remaining natural teeth by either wrought wire clasps set in the base, small finger-like projections of the base that conform to the spaces between the remaining natural teeth or with a soft gasket-like material called cusil that is attached to the base acrylic and envelops those natural teeth. Cast partial dentures are used in treatment plans for most situations. Acrylic partials are sometimes used when only one tooth, especially on the upper, is being replaced or when further tooth loss is anticipated (as with untreated gum disease) in the future since it is easier to add denture teeth to an acrylic partial than to a cast partial. The former are often called "flippers" and an example of the latter would be a cusil partial denture. Cast partial dentures need to be relined less often than full dentures because they rely more on the remaining natural teeth than the edentulous ridge for support. Acrylic partials, because they have no metal framework, are supported considerably more by edentulous areas and so need to be relined more often than cast ones.

FULL DENTURES

1. Never wear a denture to sleep at night. This time without the denture in place gives the gum tissue on your ridge a chance to breathe which helps conserve it. Studies have shown the patients who leave their dentures out at night need to have them relined less often. The only exception to this rule is when immediate dentures are placed. In this case the denture should be worn continuously until the next day to physically minimize any post-surgical swelling. It should be treated like a normal full denture thereafter.

2. When a denture is left out for a prolonged period of time, as when sleeping, it should be kept in water. This is because when the base acrylic dries out it can become quite brittle and more likely to fracture. When in the mouth, a denture is kept moist and this is not a concern.

3. Dentures may be cleaned by adding a denture cleanser, such as an effervescent tablet, to the water they are kept in over night. Gently using a soft toothbrush and a denture cream or toothpaste, however, will probably do a more effective job. Doing both is great. If you are going to use a toothbrush and a cream or paste over the sink, be sure to place a towel in the bottom of the sink first. This will reduce the risk of fracture should you drop the denture while cleaning it. Never boil a denture or use caustic chemicals, such as acetone or bleach, to clean it. A denture can be melted or dissolved in this way.

4. When wearing a denture for the first time, whether a first denture or a replacement one, speech patterns are often disturbed as the tongue, lips and cheeks attempt to function with an unfamiliar partner. Reading allowed to oneself will accelerate a return to normal speaking.

5. After a new denture has been placed, sore spots may occur that were not noticed at the insertion appointment. If this happens, Dr. McArdle must be seen so the denture can be adjusted for them. In most cases, sore spots will not resolve without adjustment of the denture. This is particularly true in the case of an immediate denture. Any irregularity of the bite that affects your ability to chew should also be brought to Dr. McArdle's attention.

PARTIAL DENTURES

1. All the instructions in the previous section apply to partial dentures as well.

2. Never ever bite a partial denture into place in your mouth. Always place it with your fingers. Human jaws can exert forces equivalent to thousands of pounds per square inch (psi). If the partial is not in exactly the correct position when biting: the metal framework of a cast partial can be warped or broken, clasps can be bent or broken, base acrylic or denture teeth can be fractured and the tongue, gums, lips or cheeks can be injured. For the same reasons, you should not attempt to remove or insert a partial denture while you are numb after having Novocain, such as might be used when you have a filling or a crown done. Trying to remove or place a partial denture when portions of the mouth are numb can cause the same kinds of problems.

3. Never ever attempt to tighten the clasps of a partial denture yourself. If the partial feels loose, bring it to Dr. McArdle so he can tighten them. This is a delicate procedure that requires experience. Clasps can be easily broken on tightening and are usually impossible to repair. It only takes Dr. McArdle a few minutes to tighten clasps and he is happy to do this at no charge if you are a regular patient in his practice.

4. Do not leave a partial denture out of your mouth for weeks or months at a time. This can lead to small shifts in tooth position that can make it difficult, if not impossible, to properly reinsert the partial. The clasps and base of a partial denture are designed to make precise contact with the remaining natural teeth on a given arch. Even minimal changes representing just a fraction of a millimeter can cause a problem.