DEFINITION OF TERMS

prosthesis

a denture, an obturator, a fixed partial denture, or a crown.

an artificial device used to replace missing body parts to restore function, appearance, and oral health

prosthodontics

a dental specialty focused on the diagnosis, planning, rehabilitation, and maintenance of patients with missing teeth using artificial replacements

tooth-supported RPD

a type of rpd that gains its support entirely from the remaining natural teeth, without relying on soft tissue for support

tooth-tissue supported RPD

a type of rpd that derives its support from both the remaining natural teeth and the edentulous ridge (soft tissue)

distal extension partial denture

a type of rpd where the artificial teeth extend beyond the last tooth with no tooth support at the back

appliance

it is any device designed to perform a specific function in the mouth

devices (such as splints, orthodontic appliances, and space maintainers) worn by the patient in the course of treatment

stability

it is the ability of the denture to resist movement or displacement in a horizontal direction

quality of a prosthesis of being firm, stable, or constant and resisting displacement by functional, horizontal, or rotational stresses.

retention

it is the ability of a denture to resist dislodgment in a vertical direction

quality inherent in the denture that resists the vertical forces of dislodgment (e.g., the force of gravity, the adhesiveness of foods, the forces associated with opening of the jaws).

interim / provisional denture

a temporary removable prosthesis used to restore function, esthetics, or even for convenience

dental prosthesis used for a short time for reasons of esthetics, mastication, occlusal support, or convenience, or for conditioning the patient to accept an artificial substitute for missing natural teeth until a more definite prosthetic dental treatment can be provided

complete denture

a dental prosthesis that replaces all of the natural dentition and is entirely supported by tissues

abutment

a tooth or a portion of a tooth, or a portion of an implant that serves to support and retain a prosthesis

height of contour

it is the most prominent part of the tooth surface when viewed from a specific angle

line encircling a tooth, designating its greatest circumference at a selected position determined by a dental surveyor

undercut

when used in reference to an abutment tooth:

—that portion of a tooth that lies between the height of contour and the gingiva

when used in reference to other oral structures:

—the contour or cross section of a residual ridge or dental arch that would prevent placement of a denture

angle of cervical convergence

the combined angle formed by opposing axial walls to the long axis of the tooth

angle viewed between a vertical rod contacting an abutment tooth and the axial surface of the abutment cervical to the height of contour.

retainer

used for fixation, stabilization, or retention of a prosthesis

a component of a dental prosthesis that secures the appliance to an abutment tooth

may be intracoronal or extracoronal and can be used as a means of retaining a removable or a fixed restoration

circumferential clasp arm

a type of retentive clasp that approaches the undercut area from above the height of contour or in an occlusal direction

term used to designate a clasp arm that originates above the height of contour and approaches the tooth undercut from an occlusal direction.

rest

a rigid component of rpd that is placed on an abutment tooth to provide vertical support, its main function is to prevent tissue-ward movement

any component of the partial denture that is placed on an abutment tooth, ideally in a prepared rest seat, so that it limits movement of the denture in a gingival direction and transmits functional forces to the tooth.

denture base

part of denture that rests on the residual bone covered by soft tissue, it serves to transmit functional forces like chewing pressure

whether it is metal or is made of a resinous material that rests on the residual bone covered by soft tissue and to which the teeth are attached

edentulous ridge

it is the part of alveolar process and its overlying soft tissue that remains after extraction of natural teeth

relining

resurfacing of a denture base with new material to improve its fit and adaptation

rebasing

it is the process of replacing the entire denture base material of an rpd without changing the position of artificial teeth

involves refitting a denture by replacing the entire denture base with new material without changing the occlusal relations of the teeth.

major connector

the main part of rpd that connects the components on one side of the arch to those on the opposite side

Part of a removable partial denture that connects the components on one side of the arch to the components on the opposite side of the arch.

minor connector

it joins the smaller components to the major connector

it serves as the link between the major connector and other functional parts

acrylic

formed from acrylic acid

acrylic resin

any of a group of thermoplastic resins made by polymerizing

pertaining to polymers of acrylic acid, methacrylic acid, or acrylonitrile; for example, acrylic fibers or acrylic resins

anatomic ridge form

surface form of the edentulous ridge when at rest or when not supporting a functional load

often recorded in a soft impression material

balanced occlusion

the simultaneous contacting of maxillary and mandibular teeth on the right and left in the anterior and posterior occlusal areas in centric or any eccentric position within the functional range

bar clasp

a type of retentive clasp that approaches the undercut area below the height of contour or from a gingival direction

type of extracoronal retainer that originates from the denture base or framework, traverses soft tissue

basal seat

oral tissues and structures of the residual ridge supporting a denture base

the tissue-covered area of the edentulous ridge (the gum and bone) where a denture rests

cast

an accurate and positive reproduction of a maxillary or mandibular dental arch made from an impression of that arch

further designated according to the purpose for which it is made, such as diagnostic cast, master cast, or investment cast

also may be used as an infinitive (to cast) or as an adjective (cast framework, or cast metal base)

casting

a metal object shaped by being poured into a mold to harden

used primarily to designate the cast metal framework of a partial denture but also may be used to describe a molded metal denture base that is actually cast into a mold.

centric occlusion

the occlusion of opposing teeth when the mandible is in centric relation

this may or may not coincide with the maximal intercuspal position

centric relation

the maxillomandibular relationship involves condyles articulating anteriorly against articular eminences, independent of tooth contact.

the most retruded mandible-maxillae relation allows lateral movements, while the most posterior lower-to-upper jaw relation allows lateral movements at specific vertical dimensions.

clasp assembly

part of a rpd that acts as a direct retainer and/or stabilizer for a prosthesis by partially encompassing or contacting an abutment

dental cast surveyor

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

also used to locate and delineate the contours and relative positions of abutment teeth and associated structures

dental stones

used to form an artificial stone reproduction from an impression

used as an investment or for mounting purposes

all dental stones are gypsum products

direct retainer

directly stabilizes the prosthesis

consists of a clasp assembly or precision attachment

placed near the edentulous area, usually on abutment teeth

component of a removable partial denture used to retain or prevent dislodgment

functional impression

impression and resulting cast of the supporting form of the edentulous ridge

artificially created by means of a specially molded (individualized) impression tray or an impression material

displaces those tissues that can be readily displaced and that would be incapable of rendering support to the denture base when it is supporting functional load

functional occlusal registration

used to designate a dynamic registration of opposing dentition rather than the recording of a static relationship of one jaw to another

guiding planes

it is a flat and parallel surface on the abutment tooth to guide the path of insertion and removal of rpd

surfaces are parallel to the path of the placement and parallel to each other

preferably these surfaces are made parallel to the long axes of abutment teeth.

incisal rest

a rest placed on the incisal edge of an anterior abutment tooth

indirect retainer

prevents it from rotating or lifting on the opposite side

placed away from the edentulous area, often anterior to the fulcrum line

part of rpd that assists direct retainers in preventing displacement of distal extension denture bases by resisting lever action from the opposite side of the fulcrum line

investment cast

cast compounded to withstand high temperatures without disintegrating to perform certain functions relative to burnout and expansion of the mold

lingual bar connector

component of the partial denture framework located lingual to the dental arch and above the moving tissues of the floor of the mouth but as far below the gingival tissues as possible

lingual rest

a rest that occupies a position on the lingual surface of an anterior tooth

linguoplate

designation given when the lingual bar major connector is attached to a thin, contoured apron adjacent to the lingual surfaces of the anterior teeth in the mandible.

mold

word used to indicate either the cavity into which a casting is made or the shape of an artificial tooth

use of the term is incorrect when referring to a reproduction of a dental arch or a portion thereof

occlusal rest

a rest placed on the occlusal surface of a posterior tooth

palatal bar

thin, broad palatal coverage with a width of less than 8 mm used as a major connector

palatal major connector

any thin, broad palatal coverage that is used as a major connector

palatal strap

proportionally thinner and broader than a palatal bar, although differentiation is somewhat objective

plastic

refers to any of various substances that harden and retain their shape after being molded.

precision attachment

refers to an interlocking device, one component of which is fixed to an abutment or abutments while the other is integrated into a removable prosthesis to stabilize and/or retain it

refractory investment

investment material that can withstand the high temperatures of casting or soldering

plaster of paris and artificial stone may be considered investment if either is used to invest any part of a dental restoration for processing

removable partial denture (RPD)

prosthesis that replaces some teeth in a partially dentate arch and can be removed from the mouth and replaced at will

residual ridge

residual bone with its soft tissue that covers the underlying area of the denture base

the exact character of the soft tissue covering may vary, but it includes the mucous membrane and underlying fibrous connective tissue

resin

used broadly for substances named according to their chemical composition, physical structure, and means for activation or curing

semiprecision rest

rigid metallic extension of a fixed or removable partial denture that fits into an intracoronal preparation in a cast restoration.

stone

use of the word in dentistry should be limited to those gypsum materials that are employed for their hardness, accuracy, or abrasion resistance

support

foundation on which a dental prosthesis rests, or to hold up and serve as a foundation

wax pattern

converted to a casting via elimination of the pattern by heat, leaving a mold into which the molten metal is forced by centrifugal force or other means.