terminology rpd

Removable Partial Denture.

• It is a dental prosthesis that replaces some teeth in a partially dentate arch, and can be removed from the mouth and replaced at will.

Abutment : It is a tooth, a portion of a tooth , or a portion of an implant that serves to support and / or retain a prosthesis.

Height of Contour : It is defined as a line encircling a tooth , desingnating its greatest circmference at a selected position determined by a dental surveyor.

• Undercut: It is the term used in reference to an abutment tooth, is that portion of a tooth that lies between the height of contour and the gingiva.

• Angle of cervical convergence:It is an angle viewed between a vertical rod contacting an

abutment tooth and the axial surface of the abutment cervical to the height of countour.

• Guiding Planes: Two or more vertically parallel surfaces of abutment teeth shaped to direct a prosthesis during placement and removal are called Guiding Planes.

Retainer

• A retainer is defined as any type of clasp, attachment, device, etc… used for the fixation , stabilization or retention.

• A retainer can be INTRACORONAL

EXRACORONAL

DIRECT

INDIRECT

• Clasp : A clasp(direct retainer) is the component of the clasp assembly that engages a portion of the tooth surface and either enters an undercut for retention or remains entirely above the height of contour to act as a reciprocating element.

Surveyor

• A dental cast surveyor is an instrument used to determine the relative parallelism of two or more axial surfaces of teeth or other parts of a cast of a dental arch.

• Support : It is defined as the foundation on which a dental prosthesis rests, or to hold up and serve as a foundation.

• Stability: defined as the quality of a prosthesis to be firm , stable , or constant and to resist displacement by functional, horizontal , or rotational stresses.

• Retention: It is the inherent quality of the denture that resists the vertical forces of dislodgement.

• Refractory Investment: It is an investment material that can withstand the high temperatures of casting or soldering.

• Refractory Cast: A cast because it is compounded to withstand high temperatures without disintegrating and , incidentally , to perform certain functions relative to the burnout and expansion of the mold.

• Path of Placement : It is the direction in which a restoration moves from the point of initial contact of its rigid parts with the supporting teeth to its terminal resting position, with rests seated and the denture base in contact with the tissues.

• Path of removal: