A fulcrum line is an imaginary line around which an RPD will tend to rotate. Fulcrum lines may be in the horizontal, frontal or vertical plane. Indirect retainers provide resistance to rotational movement of a distal extension RPD away from the denture bearing tissues around the retentive fulcrum line (Figure 2).

What is a fulcrum line in RPD?

A fulcrum line is an imaginary line around which an RPD will tend to rotate. Fulcrum lines may be in the horizontal, frontal or vertical plane. Indirect retainers provide resistance to rotational movement of a distal extension RPD away from the denture bearing tissues around the retentive fulcrum line (Figure 2).

What is indirect retention in RPD?

A secondary fulcrum line is usually established when partial denture design includes indirect retention. Indirect retention prevents the retentive clasp tips from becoming a fulcrum about which the prosthesis could rotate when forces move the denture base away from the tissue.

What is the function of indirect retainer?

The function of the indirect retainer is to prevent the distal-extension base from moving away from its seat because of cheek and tongue forces, sticky foods, or gravity on a maxillary prosthesis.

What is guiding plane in RPD?

The guiding planes are flat axial surfaces in an occluso-gingival direction on abutments. They limit the number of path of placement and removal of a removable partial denture. They aid in stabilizing the removable partial denture against horizontal forces.

What is canine rest?

4. Rest : According to GPT 9  A rigid extension of a removable partial denture that contacts the occlusal, incisal, cingulum, or lingual surface of a tooth or restoration, the surface of which is commonly prepared to receive it.

What is balance occlusion?

Balanced Occlusion is defined as the bilateral, simultaneous, anterior, and posterior occlusal contact of teeth in centric and eccentric positions. Balanced occlusion in complete dentures is unique, as it does not occur with natural teeth.

What is minor connector?

A MINOR CONNECTOR is the connecting link between the major connector or base of a RPD and the other units of the prosthesis, such as clasps, indirect retainers, and occlusal rests. 1. Minor connectors join. the major connector with other parts of the RPD. 2.

Is lingual plate an indirect retainer?

Technically, continuous bar retainers and lingual plates are not indirect retainers since they rest on unprepared lingual inclines of anterior teeth. The indirect retainers are actually the terminal rests at either end in the form of auxiliary occlusal rests or canine rests.

What is denture base?

DEFINITION. A denture base is that part of a denture which rests on the foundation areas and to which teeth are attached.

Article first time published on

What is retainer in prosthodontics?

DEFINITIONS. RETENTION is resistance to movement of a denture away from the teeth and/or tissues along the path of placement of the prosthesis. Most retention of RPDs is provided by DIRECT RETAINERS which are clasp assemblies or attachments applied to an abutment tooth to retain an RPD in position.

Is Cingulum rest indirect retainer?

Indirect retainers for Class II partial dentures are usually placed on the marginal ridge of the first premolar tooth on the opposite side of the arch from the distal extension base (Fig. 4). … A cingulum rest also can be used as an effective indirect retainer.

What is combination clasp?

A combination clasp is a circumferential retainer for a removable dental prosthesis that has a cast reciprocal arm and a wrought wire retentive clasp (GPT8). It consists of a wrought wire retentive arm and a cast reciprocal arm. The combination of a wrought alloy and cast alloy gives it the name ‘combination clasp’.

What is path of insertion?

lh e path of insertion has been defined as “the direction of movement of an appli- ance or prosthesis from the point of initial contact of its rigid parts with the support- ing teeth to the place of final rest.

What is stress breaker?

Medical Definition of stress breaker : a flexible dental device used to lessen the occlusal forces exerted on teeth to which a partial denture is attached.

What is height of contour on teeth?

The height of contour (crest of curvature) is the greatest amount of a curve, or greatest convexity or bulge, farthest from the root axis line. The height of contour on the facial or lingual surfaces of the crown is where this greatest bulge would be touched by a tangent line drawn parallel to the root axis line.

What are supporting cusps?

The supporting cusps are mandibular buccal and maxillary palatal cusps when the posterior teeth are normally related (i.e., no cross-bite or reverse horizontal overlap). … Each cusp has an inner and outer aspect (surface), which are made up of incline planes.

What is Bennett angle?

Bennett angle is the angle. formed between the sagittal. plane and the average path. of the advancing condyle as. viewed in the horizontal plane.

What is centric and eccentric occlusion?

central occlusion (centric occlusion) occlusion of the teeth when the mandible is in centric relation to the maxilla, with full occlusal surface contact of the upper and lower teeth in habitual occlusion. … eccentric occlusion occlusion of the teeth when the lower jaw has moved from the centric position.

What is denture rest?

An occlusal rest consists of two component parts-a horizontal portion and a vertical portion. The horizontal portion is that part which rests on the abutment tooth and transmits the forces of mastication to the tooth. The vertical com- ponent connects the horizontal part of the rest to the partial denture base.

What is the name of tooth rest?

1. Occlusal rests—so named because they are seated on the occlusal surfaces of posterior teeth. 2. Lingual or cingulum rests—those seated on the lingual surfaces of anterior teeth, usually maxillary canines.

What is direct retainer?

A direct retainer is any unit of a removable dental prosthesis that engages an abutment tooth or implant to resist displacement of the prosthesis away from basal seat tissue.

What is mandibular major connector?

There are six mandibular major connectors described in the literature: lingual bar, lingual plate, lingual bar with a continuous bar indirect retainer, labial bar (or plate), cingulum bar and sublingual bar. Of these, the lingual bar and lingual plate are used very frequently.

What is gingival approaching clasp?

Gingivally approaching clasps /Bar/Roach type Approach the undercut gingivally and have a push type of retention. Approach arm • It is a minor connector that connect the retentive tip to the denture base. • It crosses the gingival margin at right angle and it is the only flexible minor connector.

What is cast partial denture?

Cast partial denture is a type of partial denture comprising a cast metal framework with acrylic resin prosthetic teeth. Traditional acrylic partial dentures are less durable, retentive, and stronger than cast partial dentures.

What is refractory cast?

Refractory cast: It is a cast made of material that will withstand high temperature without. disintegration when used in partial denture casting procedure; it has an expansion to. compensate for metal shrinkage. The refractory cast has been made of investment material.

What are the major connectors?

A major connector is the component of the partial denture that connects the parts of the prosthesis located on one side of the arch with those on the opposite side. It is that unit of the partial denture to which all other parts are directly or indirectly attached.

What is a flange in dentistry?

(flanj), That part of the denture base that extends from the cervical ends of the teeth to the border of the denture.

What is the Retromolar pad?

The retromolar pad is a mass of soft tissue located at the posterior end of the mandibular alveolar ridge. This pad covers the underlying bone with surrounding attached muscle fibers. … After the loss of molars the bony alveolar process and surrounding soft tissues remodels, resorbs and blends with retromolar pad [2].

What is residual ridge?

Residual Ridge – The portion of the residual bone and its soft tissue covering that remains after removal of teeth. Residual Bone – The component of maxillary and mandibular bone, once used to support the roots of the teeth, that remains after teeth are lost.

What is flexible denture?

Flexible dentures are a type of partial denture, which are typically constructed of nylon, or other thin thermoplastics, which differ significantly from the thicker, harder acrylic that is often used in normal dentures.