Removable Components of Partial Dentures

A removable partial denture (RPD) is a dental appliance designed to replace missing teeth. It attaches to the remaining teeth with wire clasps and contains plastic denture teeth. Designed by dentists or prosthodontists, an RPD dramatically improves the appearance of the face, mouth and smile. The RPD attaches to the patient's teeth with metal clasps or precision devices that are almost invisible. The appliance helps maintain correct position of upper and lower jaws, which helps prevent joint disorders. The RPD assists with speech and keeps the remaining teeth in their proper position, protects oral tissues and helps maintain the facial contours. Removable partial dentures have several different parts and are designed from metal, acrylic or a combination of the two materials.

Major Connector

• A correctly designed RPD fits securely in the patient's mouth.

  This part of the denture joins the components of one side of the dental arch to the other. There is an upper and lower arch; an RPD replaces a minimum of two teeth on either one or both sides of the arch. There are several types of mandibular connectors for the lower jaw and maxillary connectors for the upper jaw.

Minor Connector

• The dentist or a prosthodontist designs and makes the RPD.

  This is the link between the major connector or the base of a removable partial denture and the other units of the denture. It's attached to the clasp assembly, indirect retainers, cingulum rests and occlusal rests. The connector must be rigid and put no pressure on underlying tissues of the mouth.

Direct Retainer

• The RPD requires fitting and design time.

  This prevents and retains dislodgment of the denture. It consists of a clasp whose reciprocal arms hug the teeth and prevent lateral movement of the prosthesis. A small piece, called a rest, sits adjacent to the artificial teeth and also acts as a direct retainer. An effective RPD is completely stable when the patient moves his jaws while chewing or talking. When a component shifts, it will cause oral irritation and can lead to cavities caused by this movement against the teeth.

Indirect Retainer

• Good oral hygiene is important for patients using an RPD.

  This component is a small piece of material that projects off the "U" shape of the major connector and rests on a canine tooth. It assists the direct retainer in preventing displacement or rotation of the distal (far) extension of the base of the RPD.

Physical Retainer

• An RPD keeps the jaws and teeth properly aligned.

  This is a wire mesh that forms to fit the mouth. The pink, acrylic base material attaches to this meshwork and connects to the metal framework of the partial denture.

Base and Teeth

• Teeth fit into the pink base.

  The base is pink material, usually acrylic, which resembles the gum tissue. The dentist makes a cast and molds wire mesh to fit. It must conform to the patient's mouth and gums without rubbing or causing any pressure areas. The teeth are of plastic or porcelain and match the patient's closely in color and shape. They fit firmly into the base. The RPD can be modified to add additional teeth if there is a future need.