Dentures, also known as false teeth, are prosthetic devices constructed to replace missing teeth, and which are supported by surrounding soft and hard tissues of the oral cavity. Conventional dentures are removable, however there are many different denture designs, some which rely on bonding or clasping onto teeth or dental implants. There are two main categories of dentures, depending on whether they are used to replace missing teeth on the mandibular arch or the maxillary arch.
Removable partial dentures are for patients who are missing some of their teeth on a particular arch. Fixed partial dentures, also known as “crown and bridge”, are made from crowns that are fitted on the remaining teeth to act as abutments and pontics made from materials to resemble the missing teeth. Fixed bridges are more expensive than removable appliances but are more stable.
Conversely, complete dentures or full dentures are worn by patients who are missing all of the teeth in a single arch (i.e. the maxillary (upper) or mandibular (lower) arch).
Modern dentures are most often fabricated in a commercial dental laboratory using a combination of a tissue shaded powder polymethylmethacrylate acrylic (PMMA) for the tissue shaded aspect, and commercially produced acrylic teeth available in hundreds of shapes and tooth colors.
The process of fabricating a denture usually begins with a dental impression of the maxilla or mandible. This impression is used to create a stone model that represents the arch. A wax rim is fabricated to assist the dentist or denturist with establishing the vertical dimension of occlusion. After this a bite registration is created to marry the position of one arch to the other.
Once the relative position of each arch to the other is known, the wax rim can be used as a base to place the selected denture teeth in correct position. This arrangement of teeth is tried in the mouth so that adjustments can be made to the Occlusion. After the occlusion has been verified by the dentist with the patient, and all phonetic requirements are met, the denture is processed.
Processing a denture is usually performed in a lost-wax process whereby the form of the final denture, including the acrylic denture teeth, is invested in stone. This investment is then heated, and the wax is removed through a sprue when it melts. The remaining cavity is then either filled by forced injection or pouring of the uncured denture acrylic. After a curing period, the stone investment is removed, the acrylic is polished, and the denture is complete.
A dental bridge is an appliance used to replace one or more missing teeth. These appliances are cemented into place and cannot be removed by the patient.
As the name of this appliance implies, the bridge is made out of three pieces that fit into the open space in the mouth, “bridging” the gap. Most bridges are made of a pontic tooth (or false tooth), held together by two crowns (a “cap” that covers the tooth, approximating its normal size and shape). This trio is then attached (cemented) to the abutment teeth (the surrounding teeth of each side of the gap).
Nearly everyone who has one or more missing teeth is a candidate for a dental bridge. However, the difference between proper and improper oral hygiene is, generally, what determines the success of the dental bridge. The teeth that will support the bridge must be in good periodontic health.
There are several different types of dental bridges. Your dentist or oral health specialist will recommend the most appropriate one for your mouth condition and the location of the missing tooth or teeth.
Traditional bridge
– as described above, this bridge consists of a pontic (false) tooth held together by two crowns. The trio is cemented to the surrounding teeth on each side of the gap.Resin-bonded bridge (also known as a Maryland bridge) – this type of bridge involves the pontic (false) teeth being fused to metal bands that are bonded to the back of the abutment teeth with a resin cement. This type of procedure is common when the teeth missing are in the front of the mouth.
Cantilever bridge – this type of procedure is most appropriate when there is only one abutment tooth on either side of the span.
The following recommendations will help to eliminate, or reduce, any oral health problems while your teeth are bonded by a bridge:
Brush your teeth carefully after every meal with fluoride toothpaste and a soft-bristled toothbrush, as food may become lodged causing the gums and teeth to become infected. This may lead to further complications resulting in the loss of the bridge.
Floss daily. Your dentist, or other oral health specialist, may recommend using a floss threader to carry floss under the pontic (false) tooth so it and the abutment (support) teeth can be cleaned.
Have your teeth cleaned every six months by an oral health professional.
Limit your sugar and starch intake, as debris left behind from these types of foods may turn into damaging acids, which, in addition to promoting plaque formation, may also be harmful to teeth and gums.
Avoid hard and/or sticky snacks. This includes foods such as popcorn, hard or chew candy, caramel, and/or nuts.
Most bridges last more than 10 years with proper oral hygiene.