Removable partial dentures, a complete review

By Dr. George Ghidrai

Removable partial dentures (or RPDs) can be a viable alternative to fixed bridgework or implants as a means of replacing missing teeth.

A removable partial denture consists of replacement teeth attached to a pink or gum-colored plastic base, which is sometimes connected by metal framework that holds the denture in place in the mouth.

Removable partial dentures replace one or more teeth, while full dentures replace all the teeth in a jaw.

RPDs can be removed from the mouth by the patient as opposed to fixed bridgework that is definitely cemented on the abutment teeth and cannot be removed from the mouth.

When are removable partial dentures used?

Generally, RPDs can be used in two situations:

1. As a temporary solution to restore function and aesthetics during the transition to more long-term and definitive tooth replacements.

2. As a permanent solution to replace some missing teeth when patients can't afford dental implants or fixed bridgework. In most cases, RPDs are much less expensive than either dental implants, or fixed bridgework.

   Moreover, in some clinical situations, dental implants or fixed bridges cannot be placed. For example, some serious general or local conditions can make anesthesia, surgical procedures and the overall implant placement inadvisable (see dental implants contraindications).

   On the other hand, dental bridges cannot be executed when the number of remaining teeth is not enough to support the bridge or some teeth are unsuitable (see dental bridges). In such situations, RPDs can also be viable alternatives.

Types of removable partial dentures

Removable partial dentures generally attach to the remaining teeth by means of rests, clasps or precision attachments. They are supported by the gum ridge areas where the teeth once were and, in the case of an upper RPD, the palate (or roof of the mouth). There are more types or RPDs:

• The "flipper"

  The “flipper” is a type of RPD made of acrylic plastic resin, usually indicated as a temporary denture. Flippers cling around the necks of the existing teeth, to which they attach with the addition of metal wire clasps to aid in their retention and stability.

  the "flipper" attaches to adjacent teeth with metal clasps

  This type of RPD tends to be less comfortable, loose fitting, and prone to wear and staining. Many times, it can be flipped in and out by the tongue (hence their name).

  Moreover, the metal clasps used to help keep the appliances in place can be unsightly in areas near the front of the mouth.

• Flexible partial dentures

  Flexible RPDs are made of a form of nylon, known as flexible polyamide. The material is thermoplastic; it will change shape under high heat so that it can be injected into flexible denture bases to which replacement teeth are subsequently attached.

  flexible partial denture

  Flexible partial dentures can look realistic, stay more securely in place and are more comfortable to wear. Instead of metal clasps, they have thin, gum-colored extensions that snap into the crowns of adjacent teeth near the gum line, thus providing an important cosmetic improvement.

  However, they still have stability problems, especially if the RPD is designed on the lower arch; they are also difficult to reline, rebase and repair. Flexible RPDs are most often used to restore function and aesthetics during the transition to a long-term tooth replacement.

• Partial Dentures with precision attachments

  This type of partial dentures is precision made and usually constructed of a lightweight and strong metal alloy that allows the partial denture to be very thin and unobtrusive. The artificial teeth are anchored in pink resins or plastics that mimic gingival tissue and are attached to the metal substructure.

  The removable partial denture is made to attach to natural teeth with devices called precision attachments. Precision attachments are more esthetic than clasps, providing a better stability. Crowns or bridges on natural teeth are needed to improve the fit of the removable partial denture and they are usually required with attachments.

  partial denture with precision attachments

  Partial dentures with precision attachments generally cost more than those with clasps. Dentures with precision attachments are normally used as definitive restorations.

How are removable partial dentures made?

In most cases, dental implants are today's state-of-the-art tooth replacement systems, while fixed bridgeworks represent the next best alternative. However, precision RPDs are also designed to last for years. In fact, they were quite commonplace before the routine use of implants.

The design of precision RPDs is quite critical to their success and will generally depend on two key factors:

• The number and distribution of missing teeth
• The health and condition of the remaining teeth

The removable denture development process may take more weeks and several appointments. Once your dentist determines what type of appliance is best for you, he or she will usually make a series of impressions of your jaws and determine how your jaws relate to one another and how much space is between them.

The impressions are sent to a dental lab, where the technician will create a series of models, wax forms, and plastic patterns in the exact shape and position of the denture to be made.

removable partial denture on a dental cast

One or more appointments may be needed to assess the denture for color, shape, and fit before the final denture is cast.

What to expect/do after the removable denture is finalized?

• In the beginning, your new partial denture may feel a little awkward or bulky. This happens until the muscles of the cheeks and tongue get used to the new situation. It takes 3 to 4 weeks before you get accustomed to wearing it.

• Inserting and removing the partial denture will require some practice.

• It is not unusual for minor irritation or soreness to occur and for saliva flow to increase when you first start wearing dentures. If the denture puts too much pressure on a particular area, that spot will become sore.

  Call your dentist as soon as you notice that. After making the necessary adjustments, you may be asked to wear your partial denture all the time. Although this may be uncomfortable at first, it's the quickest way to identify areas that may still need adjustments.

• Start out by eating soft foods that are cut into small pieces. Chew on both sides of the mouth and avoid foods that are extremely sticky or hard. As you become more accustomed to your dentures, eating should become a more pleasant experience.

• If you find it difficult to pronounce certain words, practice reading out loud and repeat the words that give you trouble. You will notice that in a short time you will become used to speaking properly with your partial denture.

• Follow all instructions given by your dentist. Never force the partial denture into position by biting down. This could bend or break the clasps or alter the precision attachments.

Caring for your dentures

Are dentures worn 24 hours a day?

During the first several days after receiving your denture, you may be asked to wear it all the time, including while you sleep. It is the quickest way to identify the areas on the denture that may need adjustment.

Once adjustments are made, your dentist may advise you to remove the denture before going to bed. This allows gum tissues to rest and allows normal stimulation and cleansing by the tongue and saliva. The denture can be put back in the mouth in the morning.

Cleaning your dentures

Because of the way RPDs attach to the remaining teeth and the fact that they rest on the gums, they tend to accumulate a lot of bacterial plaque. This can increase the risk of both periodontal diseases and tooth decay. Therefore, excellent daily oral hygiene together with scrupulous care of the removable denture, are all prerequisites to success.

Read this article for complete instructions on how to clean and take care of your dentures.

Adjustments

Over time, adjusting the denture may be necessary. As you age, your mouth naturally changes, which can affect the fit of the denture. Your bone and gum ridges can recede or shrink, resulting in a poorly fitting denture.

Dentures that do not fit properly should be adjusted by your dentist. This procedure is called relining or rebasing.

Poorly fitting dentures can cause various problems, including sores or infections. See your dentist promptly if your denture becomes loose, and maintain your regular visits, too.

Should I use a denture adhesive?

Always ask your dentist before using a denture adhesive, as there are situations when denture adhesives should not be used. Dental adhesives are safe as long as they are used as directed.

If the denture is well-fitting and the adhesive is only used to give added stability, there should be no side effects. If adhesives are used excessively to fill voids for an ill-fitting denture, they can be harmful to the underlying soft and hard tissues.