ACRONYMS AND ABBREVIATIONS
A.D.A. American Dental Association
ADL/ADLs Area Dental
Laboratory/Area Dental Laboratories
cc cubic centimeters
DC direct current
NCO noncommissioned officer
NJ New Jersey
NSN National Stock Number
psi pounds per square inch
PTC Productivity Training Corporation
rpm revolutions per minute
SDS sulfate dihydrate solution
US United States
USAF United States Air Force
USP United States Pharmacopoeia
VDO vertical dimension occlusion
wc water column
A range of coarse to fine granules with sharp edges used for smoothing, grinding, or polishing.
Abrasive Paste --
An abrasive suspended in a paste commonly used to smooth off small irregularities on denture teeth after gross grinding.
A taking up of a substance into the mass of another.
Abutment Tooth --
In removable partial dentures, the tooth on which a clasp is placed to support and retain the removable partial denture. In fixed
partial dentures, the teeth to which retainer castings are cemented.
A chemical agent that speeds up a chemical reaction.
A gas formed by the chemical reaction between calcium carbide and water. It is used in dentistry with a special, multiorifice torch
to solder and melt metals.
Acetylene Torch --
A blow torch designed to operate with acetylene gas.
Any one of a group of corrosive chemicals used to clean
off oxide layers or surface contaminants from gold castings.
Acrylic Resin --
The plastic widely used in dentistry for making denture
Acrylic Resin Impression Tray --
A custom tray, specially constructed on a cast of the
patient’s mouth, used for making a final impression. The tray is made from
autopolymerizing acrylic resin.
Acrylic Veneer --
A tooth- colored layer of plastic placed over the facial
surface of a metal crown to improve the crown’s appearance.
The sticking together of unlike substances.
A modification of a dental prosthesis, requested by the
dentist, after it has been completed by the specialist.
A gelatin- like substance obtained from certain seaweeds
and used in compounding reversible hydrocolloid impression materials.
An irreversible type of hydrocolloid made with salts of
To properly position in relation to another object or
A metal that consists of a mixture of two or more pure
Alveolar Process --
That specialized part of the mandible and maxilla that
surrounds and supports the roots of natural teeth.
The bony socket that holds the root of a tooth by the
An alloy of mercury, silver, and other metals used as a
restorative material and for making dies.
Not having a definite crystalline structure.
Anatomic Crown --
The part of a tooth covered with enamel.
Anatomic Teeth --
Denture teeth with cusp angles of 30° or more.
Anchor Lug --
A prefabricated metal piece used to connect a wrought
wire clasp to the resin base of a removable partial denture.
Controlling the heating and cooling of a metal in a way
that makes it soft and ductile.
The positive pole of an electric source.
Anterior Guidance --
A form of occlusion found in the natural dentition. The
working side vertical and horizontal overlap of anterior teeth responsible for
separation of opposing posterior teeth in a working movement.
Anterior Teeth --
The central and lateral incisors and the cuspids of
Anterior Tilt --
A term used in surveying the master cast. When the cast
is tipped on the surveyor table so that the anterior part of the cast is down,
it is called an anterior tilt.
Extending from the front, backward.
Pertaining to the apex or root tip.
Apical Foramen --
The opening at the end of a root of a tooth through which
the tooth receives its nerve and blood supply.
Apothecaries’ Weight --
A system of weights used in dispensing drugs. The basic
unit is the grain.
Approach Arm --
That part of a bar clasp that connects the retentive
portion to the rest of a removable partial denture framework.
Aqua Regia --
A mixture of three parts hydrochloric acid and one part
nitric acid. Gold is soluble in aqua regia.
The alveolar ridges of either the maxilla or mandible
forma horseshoe- shaped arch and are sometimes referred to as either the upper
or lower arch.
Arch Form --
The general contour or shape of the arch. Patients’
arches are sometimes classified as square, tapering, or ovoid, according to
their general shape.
An articulator that contains the condylar path elements
in its upper member and its condylar elements in the lower member.
Arkansas Stone --
A hard, smooth stone used to sharpen dental instruments.
Arrangement (of Teeth) --
The positioning of the artificial teeth in the trial
Arrow Point (Gothic Arch) --
On an articulator, the pointed pattern made by the
intersecting working and balancing paths of a stamp cusp as it travels out of
centric occlusion. The centric occlusion position is the apex of the arrow.
Articular Disc --
The circular- shaped, flat piece of fibrocartilage that
lies between the condyle of the mandible and the glenoid fossa of the temporal
Articulating Paper --
Specially manufactured carbon paper, usually supplied in
strips, which is placed between the upper and lower teeth to mark areas of
In the anatomical sense, the place of union or junction
of two or more bones of the skeleton.
A mechanical device representing the temporomandibular
joints and jaw members to which casts of the mouth can be attached for
performing prosthodontic procedures.
Artificial Stone --
Specially calcined gypsum physically different from
plaster of paris in that the grains are nonporous and the product is stronger.
Wearing away of the biting surfaces of the teeth.
A fibrous silicate of calcium and magnesium. A good
nonconductor of heat found in some dental investments. It is used in strip
form to line the casting rings of fixed prosthetic units.
Autopolymerization of Resin --
Curing or polymerization of acrylic resin without heat by
the addition of an activator and a catalyst.
Auxiliary Lingual Bar --
Same as a supplemental Kennedy bar. These extensions from
the lingual bar of a mandibular removable partial denture framework are used
to stabilize loose, periodontally involved, anterior teeth.
The metal plate constructed to fit the slot or pins of
the porcelain facing. May be manufactured or may be cast in the laboratory.
Balanced Occlusion --
A complete denture occlusion in which there is multiple
anterior and posterior contact on the right and on the left in lateral and
Balancing Side --
The side opposite the working side of natural teeth or a
A major connector used in removable partial denture
construction to connect the right and left sides of the framework.
Bar-Type Clasp --
A type of clasp in which the retentive tip approaches the
undercut from below the survey line.
Basal Seat Area --
The area of the oral structures that maybe used to
support a denture.
That part of a removable prosthesis that retains
artificial teeth. The base of a removable prosthesis is made of metal or
Base Metal --
A metal other than noble metals. Copper is a base metal.
Gold and platinum are examples of noble metals.
A foundation for setting artificial teeth. A foundation
of making complete denture jaw relationship records.
Baseplate Wax --
Thin sheets of wax used to wax up dentures and trays and
for many other purposes.
Beading (Casting) --
Scoring a cast in any desired area to provide a seal
between the finished prosthesis and the soft tissue.
Beading (Impression) --
Rimming an impression with a wax strip before pouring so
that all critical impression landmarks show up in the cast.
Wax derived from the bee’s honeycomb that is used in
many dental waxes.
Bennett Movement --
The lateral bodily shift of the mandible resulting from
movement of the condyles on the lateral inclines of the temporal fossae when
the mandible moves laterally.
The slope or slant of a surface or edge.
Bicuspid or Premolar --
A tooth having two cusps.
Bifurcated, Forked --
Having two roots.
Having two sides. Any removable partial denture having a
major connector is called a bilateral appliance.
Blind Vent --
A riser or vent which does not extend outside the mold.
Blow Torch --
A device designed to mix gas and air so that it can be
ignited and the flame directed on an object to heat or melt it.
The process of eliminating undesirable undercut areas of
a cast or denture. Most frequently used in preparing a cast for removable
partial denture construction. The undercut areas below the survey line on the
teeth are blocked out with wax.
Blockout Tool --
A rod used in the surveyor spindle to remove excess wax
between the height of contour and the gingival border of abutment teeth on
Body of a Clasp --
The rigid part of the clasp formed by the junction of the
occlusal rest, the shoulders of the clasp arms, and the minor connector or
Boiling Point --
The temperature at which a substance boils.
Boley Gauge --
A caliper- like instrument calibrated in millimeters and
used for fine measurements in the laboratory.
The chewed up mass of food and saliva.
Borax or Sodium Tetraborate --
A white crystalline substance used as a flux in soldering
and casting procedures.
Boxing an Impression --
The matrix of wax wrapped around the impression for
confining the plaster or stone as the cast is poured and to preserve
Boxing Wax --
Wax in strip form used to box an impression.
Resistance to displacement in a lateral direction from
Bracing Arm, Reciprocal Arm --
The arm of a clasp which acts principally as a brace
rather than a retainer.
An alloy of about 60 to 70 percent copper and the
See fixed partiai denture.
Brinell Hardness (BHN) --
An index number denoting the relative surface hardness of
a material, Used in testing softer metals and nonbrittle materials such as
gold, copper, and silver.
Broken Stress Fixed Partial Denture --
A fixed partial denture which has one joint that is not
soldered, but instead is held together by a male (key) and female (keyway).
Pertaining to the cheek; the surface of the tooth toward
Buccal Frenum --
The string- like tissue which attaches the cheeks to the
alveolar ridge in the bicuspid region of each arch.
Buccal Groove --
A landmark on the buccal surfaces of mandibular molar
teeth. It extends vertically from the occlusal surface down toward the
Buccal Notch --
The V- shaped notch in the impression or denture formed
by or for the buccal frenum.
Buccinator Muscle --
The cheek muscle.
To polish by rubbing or by holding the object against a
revolving felt wheel impregnated with a polishing agent.
A small rotating instrument used in the dental handpiece
for preparing cavities in teeth.
Burlew Discs --
Rubber wheels impregnated with pumice and used for
polishing dental restorations.
The drawing or flattening out of a malleable metal
through pressure. If a rounded instrument is repeatedly rubbed across the
margin of a soft gold casting and the tooth, the gold will be thinned and
spread over onto the enamel of the tooth.
The process of eliminating the wax pattern from the mold
Burnout Temperature --
The temperature which must be reached to properly
eliminate a wax pattern from the mold and expand the mold.
Butt Joint --
A type of joint in which the two pieces to be joined
touch each other but do not overlap.
Calcification of Teeth --
Deposition of lime salts in the formation of a tooth.
The hard calcium- like deposit which forms on teeth and
on artificial dentures.
Camper’s Line --
An imaginary line on a patient’s face running from the
anterior border of the ala of the nose to the superior border of the tragus of
the ear. The dentist uses this line to check the orientation of the occlusal
plane of a complete denture.
Cancellous Bone --
A type of bone which contains many small air spaces
within its mass. The spaces should not be confused with large hollows or
Cuspid Eminence --
The prominence of labial bone which overlies the upper
Cantilever Fixed Partial Denture --
A fixed partial denture with only one abutment.
Capillary Attraction --
The characteristic by which a liquid in contact with a
solid is elevated or depressed as in a capillary tube.
Carbon Marker --
A graphite stick that fits into the surveyor spindle used
to make a line or mark on the master cast when surveying.
A trade name for silicon carbide. Extremely hard blue
crystals used as an abrasive in many dental stones and points.
Carnauba Wax --
A type of wax obtained from the South American palm and
used in some dental materials.
Cast Base --
The metal portion of the removable prosthesis that covers
the edentulous ridges and supports artificial teeth. A cast base is made of
The positive reproduction of the mouth in stone or
similar material upon which a prosthetic appliance is constructed.
An object formed in a mold or the forming of a casting in
Casting Machine --
A device designed to hold the investment mold and melted
metal which has the capability of forcing the melted metal into the mold by
either centrifugal force, air pressure, or vacuum.
A substance which accelerates a chemical reaction without
entering into the reaction itself.
The negative pole of a source of electric current.
Dental glues that have a dual purpose- hold a casting on
an abutment tooth and protect the pulp against thermal shock.
A soft, bone- like structure covering the root surface of
A heat measuring scale calibrated so that the freezing
temperature of water is O degrees and the boiling temperature of water is 100
The hundredth part of a meter; 2.54 centimeters equal 1
Central Fossa --
The rounded, relatively shallow depression found in
molars in the approximate middle of the occlusal surface.
Central Sprue --
The main channel leading into a mold.
Centric Occlusion --
Maximum contact between opposing natural or artificial
teeth, usually occurring in the midline.
Centric Relation --
The rearmost, midmost, and uppermost position that the
condyles of the mandible can occupy in the glenoid fossae at a given amount of
A force in a direction from the center outward.
A force in a direction from the periphery toward the
center. The opposite of centrifugal.
Having to do with the use of porcelain.
A mineral wax often used as a substitute for beeswax.
Pertaining to the neck of a tooth.
Cervical Line --
Cementoenamel junction; the line where the cementum and
the enamel join.
The neck of a tooth.
Chalk (Calcium Carbonate) --
A powder used for final polishing and also as a
separating medium when adapting baseplates to the stone cast.
Characterization (of Dentures) --
Anything done to a denture to make it look like it
belongs in the patient’s mouth. This can include staining the denture base
for people of color, special tooth arrangements, staining the denture teeth,
Checked Tooth --
A tooth with a hairline crack.
Chewing Cycle --
The complete motion the jaw makes during a single
A sharp bevelled instrument used to trim around the necks
of artificial teeth embedded in acrylic resin.
The lathe attachment that grips the various drills,
shaping heads, abrasive wheels, or buffing wheels for use.
Circumferential Clasp --
That group of clasps that approach the undercut portion
of a tooth from above the survey line.
The part of a removable partial denture which partly
encircles the abutment tooth and helps to retain and stabilize the appliance.
Clasp Arms --
The shoulders and tips of a clasp. The part of the clasp
which extends from the body out to the end.
Clasp Shoulder --
For those clasp arms that exit from a body, the shoulder
is that one- third of a clasp arm closest to the body.
Cleft Palate --
An opening in the palate. It may be in the hard or soft
palate or both.
Cleft Palate, Acquired --
A cleft caused by surgery, disease, or accident.
Cleft Palate, Congenital --
A cleft palate present at birth.
Clinical Crown --
That part of a crown visible in the mouth near the gum
The sticking together of the like substances.
Cold Cure --
The polymerization of acrylic resins at room temperature.
Cold Flow --
Change in shape or dimension at a temperature lower than
the normal softening point of the material.
The neck of an artificial tooth below the cervical line.
It is used to embed and retain the tooth in a denture base.
Combination Clasp --
A circumferential clasp having one cast arm and one
wrought wire arm.
Compensating Curve --
Denture teeth are set on anteroposterior and lateral
curves for purposes of achieving a balanced occlusion. The combination of the
two curves is called the compensating curve.
Complete Denture --
A dental prosthesis that replaces all natural dentition
and the associated structures of the maxillae or the mandible.
Compression Molding --
The method of denture molding which employs a two piece
split mold. The acrylic resin dough is placed between the two halves of the
mold and cured under pressure.
The process of making a substance more compact.
The property of conducting heat or electricity. Silver
and copper are two of the best conductors.
Condylar Guidance --
A device on an articulator which is intended to produce
guidance in the articulator’s movements similar to that produced by the
paths of the condyles in the temporomandibular joints.
Condylar Indications --
The angle of inclination of the condylar guidance to the
horizontal plane of the articulator.
The rounded articular surface at the articular end of a
Condyle Head --
Condyle Path --
The path of the mandibular condyle in the
temporomandibular joint during mandibular movement.
Condition occurring in the offspring before birth.
Connective Tissue --
The tissue which binds together and is the support of the
various structures of the body.
In removable partial dentures, a part of the framework
which serves to connect two parts with another. Connectors are divided into
major and minor.
Contact Area --
The area on a tooth that touches an adjacent tooth.
Normally, found on both mesial and distal surfaces of all teeth except the
Continuous Bar Retainer --
Type of lower removable partial denture which employs a
second or auxiliary bar with the lingual bar. Also called a double lingual
Used as a noun, contour is the shape of a surface. Used
as a verb, contour means to shape into a desired form.
A term for the upper half of a denture flask.
A metal casting made to fit a preparation on the tooth. A
crown is then constructed over the coping. The coping may be made with a post
which fits into the root canal of a nonvital tooth or it may consist simply of
a thin covering over a crown preparation of a vital tooth. A coping can be
cast from metal or made from a highly stable resin.
Copper Band --
Hollow cylinders made of thin copper of various diameters
used to make impressions for crowns and inlays.
Pertaining to the crown portion of a tooth.
Creep, Cold Flow --
Change in shape of a substance without the addition of
heat. Amalgam fillings sometimes change shape under the forces of mastication.
Crest of the Ridge --
The high point of the alveolar ridge.
In posterior areas, a reversal of normal stamp cusp to
opposing fossa relationships. Opposing anterior teeth are in cross- bite when
normal horizontal overlap is reversed.
Cross Section --
A cut section of an object, made so that the interior of
the object can be examined.
In anatomy, that part of the tooth that is covered by
enamel. In the laboratory, that part of the tooth which is visible on the
The heat resistant container used to hold the metal while
it is melted preparatory to casting. Also, a porcelain container used to hold
acid for pickling.
Crucible Former --
The device used to hole the sprued wax pattern upright in
the casting ring when it is invested. It is shaped to forma funnel for the
gold as it enters the mold. It is sometimes erroneously called a sprue former.
Crushing Strength --
The amount of pressure required to crumble or crush a
Solidification of a gaseous or liquid substance.
Cure of a Denture --
To bring about polymerization of the powder and liquid.
Curve of Spee --
The lower natural teeth, including the lower incisors and
cuspids, present an arch- like arrangement when viewed from the side.
A cusp is a cone- shaped elevation on the occlusal
surface of a molar or bicuspid and on the incisal edge of a cuspid.
Cuspid (Canine) --
A tooth having one cusp or point; the third tooth from
Cuspid Line --
The vertical line which the dental officer scribes on the
occlusal rims to indicate the position that the cuspid tooth is to occupy in
Custom Tray, Individual Tray --
An impression tray made from a preliminary impression
used to make the final impression.
Dappen Dish --
A glass medicine dish.
A wetting agent used to lower surface tension of an
investment so that it will flow more easily over the wax pattern.
Deciduous Tooth (Primary Tooth or Baby Tooth) --
A tooth that will be replaced by a permanent tooth.
Removal of the denture from the mold in the flask.
To remove the moisture from a substance.
The quality of being compact or dense. See specific
Dental Arch --
The horseshoe- like arrangement of upper teeth, lower
teeth, or a residual ridge is sometimes referred to as an arch.
Dental Wax --
Any of the various waxes used in dentistry.
Dental Wrought Wire --
A gold alloy in wire form manufactured by drawing the
gold through die plates of varying diameters.
The tissue of the tooth underlying the cementum of crown
which makes up the bulk of the substance of the tooth.
The natural teeth as a unit.
A prosthesis replacing missing teeth.
Denture Base Material --
The material of which the denture is made, exclusive of
Denture Chisel --
An instrument with a bevelled cutting edge designed to
trim the denture material around the necks of the teeth. They are usually
supplied in sets of two— a right and a left.
Denture Staining --
The process of adding pigments to the facial flange of
the denture to more closely simulate natural mouth tissue.
Deoxidizing Investment --
Same as reducing investment.
To make dry to remove all moisture.
Desirable Undercut --
The part of an abutment tooth below the survey line which
can be engaged by the clasp tip to retain the removable partial denture.
A wetting agent used in denture work to aid in the
removal of wax from the denture mold.
Developmental Groove --
A groove formed by the union of two lobes during the
development of the crown of a tooth.
Dew Point --
The temperature of the atmosphere at which moisture
condenses and begins to be deposited as dew or droplets of water.
The statement by the dental officer, following
examination of the patient, that a certain disease condition is present.
The measurement of the width through the center of a
Diamond Point --
Small mounted points which have been impregnated with
diamond particles. They are designed for use in the dental handpiece.
A space between the teeth. Most commonly a space between
the upper central incisors.
The undercut hollow opening found in an artificial tooth
for the purpose of holding the tooth in the denture base material.
An exact positive reproduction of an object. A die is
made from an impression of the prepared tooth.
Dimensional Stability --
The ability of a material to retain the shape in which it
Direct Current --
Current in which the electricity flows along a conductor
in one direction.
Direct Inlay Technique --
The method of inlay construction in which the wax pattern
is made on the tooth in the mouth by the dental officer.
Direct Retainer --
The part of a removable partial denture appliance
designed to directly resist dislodgement; for example, the clasps.
A flat circular plate usually impregnated with an
abrasive agent such as silica, garnet, emery, or some other agent. Used in the
laboratory in smoothing and polishing operations.
An agent that kills infecting agents: for example,
Farthest from the midline of the mouth; the distal
surface of a tooth.
Occlusion— Angle’s Class II.
Double Lingual Bar --
Type of lower removable partial denture which employs a
second or auxiliary bar with the lingual bar. Also called a continuous bar
The moldable mixture formed by combining acrylic resin
powder and liquid.
An irregular outline form used to mechanically lock an
object in place.
The lower half of a denture flask.
A medicinal substance.
Dry Heat --
The heat of a flame as opposed to moist heat from a water
The property of a metal which permits it to be drawn into
a wire without breaking.
Duplicate Cast --
A cast produced from an impression of another cast.
Duplicating Material --
A substance such as hydrocolloid used to make an
impression so that an accurate copy of the case can be produced.
Duplicating a Cast --
The process of producing an exact positive copy of a cast
using an agar mold.
Capable of being stretched or compressed and return to
its original shape.
Elastic Limit --
The extent to which a material may be deformed and still
return to its original form after removal of the force.
Electric Current --
The flow of electrons from one point to another.
Either pole or terminal of an electric source.
The liquid used in electroplating.
Deposition of a coating of metal on a surface using a
source of electricity and an electrolyte.
The amount metal will stretch before it breaks.
The occlusal, facial, or lingual sloping space formed by
the contacting proximal surfaces of adjacent teeth.
An abrasive substance used as a coating on paper discs
which are used to smooth and polish.
A prominence or projection, especially one upon the
surface of a bone.
The white, compact, and very hard substance that covers
and protects the dentin of the crown of teeth.
Enamel Rod --
The microscopic prisms, held together by an
intercementing substance. that form the bulk of the enamel.
The branch of dentistry that deals with the diagnosis and
treatment of nonvital teeth.
Equilibration of Occlusion --
To equalize; to remove high spots and areas of
interference to adjust the contact areas between the upper and lower teeth so
that each tooth carries an equal share of the occlusal load.
Wearing away of tooth substance by the combined action of
a chemical agent and mechanical wear.
Harmony of form, color, and arrangement. The quality of
The causative factors which produce a disease.
An aromatic oil derived from cloves. It relieves pulpal
pain and is used with zinc oxide as a temporary sedative cement. It is a
principal ingredient in zinc oxide- eugenol impression pastes.
Outside of the mouth.
Extrusion of a Tooth --
To raise up out of its socket.
A device used to record the relationship between the
maxillae and the temporomandibular joints and to transfer this relationship to
Face-bow Fork (Bitefork) --
A device used to attach the face- bow to an occlusion rim
for a face- bow transfer.
Face Form --
The outline of the face from an anterior view.
Face Profile --
The outline of the face from the side or lateral view.
Pertaining to the face. The surface of the tooth or
appliance nearest the lips or cheeks. Used synonymously for the words "buccal"
The thin veneer of porcelain or acrylic which closely
fits a metal backing, used in fixed and removable partial dentures.
Female Attachment --
The part of a precision attachment that the male part
fits into, for example, nut- female, bolt- male.
The shaping and contouring of a waxup of a denture or of
the denture itself which is done to simulate natural tissue.
A flash of excess metal which results from poor investing
or burnout technique.
The proportion of pure gold in a gold alloy, the parts
per 1000 of gold.
The process of smoothing and trimming a prosthesis before
final polish or the entire procedure of smoothing and polishing.
Finish Line (Artificial Tooth) --
The raised line in the cervical region of an artificial
tooth which is used as a guide in trimming the wax on the denture base
Finishing Line --
In removable partial dentures, the special preparation
placed in the metal to form a definite sharp junction between the metal and
the acrylic resin.
First Molar --
The 6- year molar. Sixth tooth from the midline.
Fissure, Dental --
A fault in the surface of a tooth caused by the imperfect
joining of the enamel of the different lobes.
An abnormal passageway between two hollow parts or
extending to an outer surface.
Fixed Bridge --
See fixed partial denture.
Flabby Tissue --
See hyperplastic tissue.
The part of the denture base which extends on the facial
or lingual surface from the finish lines of the teeth to the periphery.
The overflow of denture base material which results from
overpacking the denture mold. Also, the thin metal fins which sometimes occur
Flash Point --
The temperature at which a vapor will ignite.
A metal frame constructed in sections for holding the
casts and the investment during the packing and curing phases of denture
construction. The metal ring used to invest a wax pattern. Also, to invest the
denture and cast in the denture flask.
The process of investing a waxed pattern to create a
Flat Plane Tooth --
A nonanatomic tooth which has no cusps.
Capable of being bent without breaking.
Flexure Line, Vibrating Line --
The most anterior area of the soft palate in which
movement or vibration occurs during functions such as swallowing.
Deformation of a material under loading.
Flow on Wax --
To melt and apply the wax in liquid form.
A substance used to prevent or remove an oxide film from
the surface of a heated metal. In porcelain work, an agent which lowers the
fusion temperature of the porcelain.
An exceedingly thin sheet of metal.
An opening or perforation in bone for the entrance or
exit of blood vessels and nerves. Also, the apical foramen in a tooth.
Fossa, Dental --
A rounded depression in the enamel of a tooth.
Fovea Palatina --
One or two small indentations in the region of the
junction of the hard and soft palates formed by a coalescence of mucous
Fox Plate --
A device occasionally used by dental officers in
establishing the occlusal plane on occlusion rims.
The metal skeleton of a removable partial denture.
Freehand Waxing --
A method of waxing in which the wax is flowed from an
instrument directly onto the refractory cast to form the wax framework.
Free-way Space --
The space between the occlusal surfaces of the teeth when
the mouth is at rest.
Frenum or Frenulum --
The small band or fold of connective tissue covered with
mucous membrane which attaches the tongue, lips, and cheeks to adjacent
Capable of being easily crumbled into small pieces;
Frontal Bone --
The bone which forms the front part of the skull.
The support upon which a lever rests when a force is
applied. In removable partial dentures, an abutment tooth may act as a fulcrum
for the appliance.
Fulcrum Line --
An imaginary line through the abutment teeth around which
a removable partial denture would rock if not prevented from doing so.
Fully Adjustable Articulator --
A very sophisticated articulator that has enough controls
(adjustments) to almost duplicate a person’s jaw movements.
Furnace, Burnout --
The gas or electric oven used to eliminate the wax from a
Furnace, Porcelain --
A specially constructed oven used to fuse dental
Capable of being melted.
Fusion Temperature --
The highest temperature to which an alloy can safely be
exposed in the soldering process, usually close to the lower limit of the
A measure of the thickness or diameter of an object.
An instrument used to measure.
Galvanic Current --
A current of electricity produced by chemical action
between two dissimilar metals suspended in liquid.
An abrasive, glass- like coating on paper discs that is
used to smooth and polish.
Solidification of a liquid substance in which a gel forms
and acts as a matrix between the undissolved particles. Alginate gels as it
The gum tissue.
Gingival Crevice --
The trough formed by the attachment of the gingiva to the
crown of the tooth.
Removal of the gingival tissue from around the necks of
Inflammation of the gum tissue.
The final firing of porcelain in which a high gloss is
imparted to the material.
A noble metal used extensively in dentistry, most
commonly, in the form of alloys.
Gold Alloy --
An alloy consisting of gold mixed with other metals such
as silver, platinum, copper, and palladium.
The basic unit for the apothecaries’, avoirdupois, and
troy systems of weight. A troy grain is 1/ 24 of a pennyweight.
Grain Growth --
The merging of smaller grains into larger grains of metal
during prolonged heating of the appliance at excessively high heat. This
produces a brittle metal.
A unit of weight in the metric system which is equal to
approximately 15 grains apothecaries’.
An elongated ditch- like depression on the surface of a
Half Flasking --
The process of investing the denture in the lower or
first half of the denture flask.
Hamular Notch --
A landmark found just posterior to the tuberosity. See
Hanau Articulator --
A semiadjustable articulator manufactured by the Hanau
Handpiece or Straight Handpiece --
The instrument used to hold and spin burs and mounted
points in dental operations.
Hardening Heat Treatment --
The controlled heating and cooling of the alloy to
produce a high degree of hardness and a low degree of ductility.
Hard Palate --
The anterior two- thirds of the roof of the mouth
composed of relatively hard, unyielding tissue.
Heat Soaking --
The process of allowing the invested inlay or partial
denture to remain in the oven at the burnout temperature for a prescribed
length of time to remove all carbon and to properly expand the mold.
Heat Treatment --
In its broadest sense, the annealing or softening of the
gold and the controlled cooling or hardening. Sometimes the term, "heat
treatment" is confined solely to the hardening process.
Heel of a Denture --
The posterior extremities of a denture. The heels
correspond with the retromolar pad area of the lower denture and the
tuberosity area of the upper.
Height of Contour --
The greatest circumference of a crown of a tooth.
High Lip Line --
The horizontal line which the dental officer marks on the
occlusion rim to indicate the approximate level of the upper lip when the
patient smiles. It is used to help select the length of the anterior teeth.
Hinge Axis --
An imaginary line through both condyles around which the
mandible can rotate without downward, forward, or lateral movement.
Hinge Joint --
A joint, such as the knee joint, which moves in only two
Horizontal Overlap (overjet) --
The projection of the upper anterior and posterior teeth
beyond the lower teeth in a horizontal direction.
The addition of water to a substance; for example,
plaster which has absorbed water from the air.
A trade name for a form of gypsum which is harder and
more durable than ordinary dental plaster.
An organic compound made up solely of hydrogen and
An impression material used extensively in dentistry. May
be reversible agar type or irreversible alginate type.
Hydrocolloid, Irreversible, Alginate Type --
An impression material supplied as a powder to be mixed
with water. It can only be used once, hence the name irreversible.
Overgrowth of a part due to an increase in size and
number of cells.
Hyperplastic Tissue --
Tissue of increased size and excessively movable.
Immediate Denture --
A complete or partial denture made before the natural
teeth, which are to be replaced, are extracted. It is inserted at the time the
teeth are extracted.
A negative reproduction of a given tissue area made to
reproduce a positive form or cast of the area.
Impression Paste --
A material usually supplied as a base and a hardener to
be mixed together and used as a corrective impression material.
Impression Plaster --
Plaster of paris made expressly for mouth impressions. It
contains accelerators, and usually coloring and flavoring agents. It may also
Impression Tray, Individual --
A tray of acrylic resin or other material made to fit the
individual patient’s mouth more closely than would be possible with a stock
Impression Tray, Stock --
A metal device, formed in the general shape of an arch,
used for confining the impression material and carrying it into the mouth for
the purpose of obtaining an impression.
Pertains to the cutting edge of the anterior teeth.
Incisal Edge --
The biting edge of an anterior tooth.
Incisal Pin --
The pin that fits into the upper member of the
articulator and rests on the incisal table. It maintains a selected amount of
opening between the bows of the articulator.
Incisal Rest --
The projection of an anterior clasp assembly, which rests
on the incisal edge of the tooth and prevents displacement of the appliance in
a gingival direction. An incisal rest may also be designed independent of a
Incisal Table --
The table on the articulator upon which rests the incisal
guide pin. May be adjustable or nonadjustable, depending on the type of
Incisive Foramen --
An exit hole for blood vessels and nerves found behind
the maxillary central incisors in the midline. The foramen is covered by the
Incisive Papilla --
A small pad of tissue, located at the midline just behind
the crest of the maxillary ridge which protects the vessels and nerves as they
exit from the incisive foramen.
A tooth with a cutting edge; the centrals and laterals.
Inclined Plane --
A surface which slopes at an angle from the horizontal
A guide, usually of stone, used to reposition teeth or
other parts in some original position.
Indirect Inlay Technique --
A technique of waxing the pattern on a die outside of the
Indirect Retainers --
A part of a removable partial denture framework on the
opposite side of the fulcrum line which resists tipping forces and designed to
counteract those forces.
Induction Current --
The process of generating an electric current in a
conductor by means of a magnetic field.
Induction Casting Machine --
A specially constructed casting machine which melts metal
by means of an electric current of extremely high frequency.
The area on a tooth below the survey line,
Infrabulge Clasp --
See bar clasp.
Gold supplied by the manufacturers in the form of one or
two pennyweight pieces. Some of the chrome alloys are supplied in small
cylinders also called ingots.
Initial Set --
The first hardening of a gypsum product.
Injection Flask --
A denture flask designed to permit compression molding of
an acrylic resin denture with a sprue leading into the mold.
A restoration made to fit inside a prepared tooth cavity
and then cemented into place.
The interlocking or fitting together of opposing parts as
with the cusps of the maxillary and mandibular teeth.
Intermaxillary Space --
The space between the crests of the upper and lower
Intermediate Abutment --
The middle abutment in a three abutment fixed partial
denture. In a fixed partial denture from cuspid to second molar with the
second bicuspid present, the second bicuspid is the intermediate abutment.
Between adjoining tooth surfaces.
Interproximal Space --
Space situated between two adjacent teeth.
Inside the mouth.
Intraoral Tracer --
A device used for registering centric relation. The
tracing is made within the mouth.
Inverted Spruing --
A method of spruing a cast removable partial denture in
which a hole is made in the investment model so that the sprue approaches the
wax pattern from underneath.
To surround, envelop, or embed an object in an investment
In dentistry, the plaster-type material used to enclose a
waxed pattern in the flask, thus forming a mold. Also, a heat resistant
material used to enclose a wax pattern before burning out the wax, thus
forming a mold.
Investment Cast --
The refractory cast on which the removable partial
denture frame pattern is waxed and cast.
Jacket Crown --
A complete crown restoration made of acrylic resin or
A common name for the maxillae or mandible.
Jaw Relation --
Relation of the mandible to the maxillae.
The preparation, such as a groove made in an object,
against which a stone matrix is poured. The hardened stone matrix can then be
removed and returned to its original position as often as desired. Also, to
prepare a surface with a cut or groove.
Knoop Hardness --
An index of the hardness of a material.
Pertaining to the lips. The surface of an anterior tooth
opposite the lips.
Labial Bar --
The metal piece or major connector that connects the
right and the left sides of a lower removable partial denture. It is contoured
to the labial tissue anterior to the lower teeth.
Labial Frenum --
The connective tissue which attaches the upper or the
lower lip to the alveolar ridge at or near the midline of both upper and lower
Labial Notch --
The V- shaped indentation in an impression or denture
formed by or for the labial frenum.
Lamina Dura --
The inner bony wall of the tooth socket.
The area of investment stone extending from the periphery
of the lower half flasked denture to the edge of the flask.
Lateral Condylar Path --
The path of the condyle in the temporomandibular fossa
when the mandible moves laterally.
Lateral Incisor --
An anterior tooth located just distal to the central
incisor. The second tooth from the midline.
Lateral Interocclusal Record --
A jaw relationship record of the teeth with the mandible
in a functional position.
The processor method of forming a ledge in the blockout
wax on an abutment tooth. The ledge is created in the exact area where the
retentive tip of the clasp is to be placed.
Any wound or local degeneration.
A mechanical principle in which force is multiplied by
extending the lifting force farther from and on the opposite side of the
fulcrum from the object to be moved.
Line Angle --
The angle formed by the union of two surfaces of a tooth.
The junction of the mesial surface with the labial surface of an incisor is
called the mesiolabial line angle.
Pertaining to the tongue. The surface of a tooth or
prosthesis next to the tongue is the lingual surface.
Lingual Bar --
The metal piece or major connector used to connect the
right and the left sides of a lower removable partial denture. It is contoured
to the lingual tissue behind and below the anterior teeth.
Lingual Flange --
The part of a denture or impression which extends from
about the crest of the ridge to the periphery on the lingual surface.
The band of tissue which attaches the tongue to the floor
of the mouth.
The indentation on the lingual periphery of a lower
impression made by the lingual frenum. Also, an indentation provided in the
same area of the denture to allow free movement of the lingual frenum.
The solid plate of metal which is continuous with the
lingual bar and which rests against the lingual surfaces of the anterior
teeth. It functions as a connector and sometimes as a periodontal splint for
Lingual Rest --
A rest on a removable partial denture which is placed on
the lingual surface of an anterior tooth. Also, a lingual rest is sometimes
used on the free end of a cantilever fixed partial denture.
Long Axis --
An imaginary line which might be drawn in a vertical
plane through the center of a tooth.
Low-Fusing Alloy --
Any one of the alloys which melts at a very low
Major Connector --
A part of a removable partial denture framework which
connects one side of the appliance with the other. A lingual bar is an
Male Attachment --
The projecting part of a precision attachment made to fit
the female part of the attachment.
The property of a metal which permits it to be extended
in all directions without breaking.
Small elevations of enamel present on incisors as they
erupt. They are quickly worn down in mastication.
The lower jaw.
Referring to the mandible or lower jaw.
The spindle or shank which fits the lathe chuck or
handpiece and holds a stone or disc.
The border or boundary as between a tooth and a
restoration. Also, the outer edge of a crown, inlay, or onlay.
Marginal Ridges --
The elevations of enamel which form the mesial and distal
margins of the occlusal surfaces of the bicuspids and molars and the mesial
and distal margins of the incisors and cuspids on the lingual.
Masseter Muscle --
A muscle of mastication. It extends from the external
surface of the angle of the mandible to the zygomatic process.
Master Cast --
The positive reproduction in stone made from the final
Master Impression --
The impression from which the master cast is made.
Chewing of food.
The mold in which something is formed.
The upper jaw.
Plural of maxilla.
Referring to the maxilla or upper jaw.
Maxillomandibular Record or Registration --
A record of the relationship of the mandible to the
Toward the middle.
Median Line --
An imaginary line which extends through the middle of the
face. Also, the midline of a cast.
Median Raphe --
The fibrous tissue which extends along the midline of the
Melting Point --
The point at which a pure metal will become molten or
changes from a solid to a liquid.
Melting Range of an Alloy --
The interval between the temperature at which the alloy
beings to melt (solidus) and the temperature at which it is completely molten
Mental Foramen --
A foramen in the facial surface of the mandible near the
roots of the bicuspids, through which pass the mental vessels and nerves.
A metallic element, liquid at room temperature. It is
mixed with silver alloy for amalgam dies.
The surface of a tooth nearest the midline in a normal
A substance which is to some degree malleable and ductile
and which conducts heat and electricity.
Metal Base Denture --
A denture in which the base material is largely metal.
Methyl Methacrylate --
Acrylic resin. A synthetic resin used as a denture base
material for artificial dentures.
The imaginary line through the middle of an object which
divides it into equal parts.
One- thousandth of an ampere.
A unit of length in the metric system which is equal to
1000 microns or the one thousandth part of a meter.
The final refinement of the occlusion accomplished by
placing a layer of abrasive paste on the occlusal and incisal surfaces of
denture teeth and moving the maxillary teeth against the mandibular teeth in
functional movements. It is done on the articulator.
Minor Connector --
The part of a removable partial denture frame which
unites clasps and rests to the remainder of the framework.
Modeling Plastic --
A material used extensively for making impressions.
Contains shellac, talc, glycerine, wax, tallow and palm oil.
Modulus of Elasticity --
A complex measure of the elasticity of a wire in relation
to the stress to which it is subjected.
One of the grinding teeth situated in the posterior
region of the mouth. The teeth behind the premolars.
The hollow form or matrix in which an object is castor
shaped. Also, the shape of an artificial tooth.
Methyl methacrylate liquid.
The stone which attaches the cast to the articulator.
Also, the attachment of the casts to the articulator with stone.
Mounting Ring --
The removable round metal piece which attaches to the
upper and lower members of the articulator and to which the dental casts are
fixed in mounting.
Mucobuccal Fold --
The junction between the cheek and the alveolar mucosa of
the upper or lower jaw.
Mucous Membrane --
The moist soft tissue which lines the mouth.
Mylohyoid Ridge --
The ridge of bone which begins on the lingual of the body
of the mandible in the third molar area, runs downward and forward to the
lower border of the mandible in the region of the midline. It forms the
attachment for the mylohyoid muscle.
Nasal Bone --
Two small bones which form the arch of the nose.
Noble Metal --
A metal, such as gold, not readily oxidized at ordinary
temperatures or on heating.
Nonanatomic Teeth --
Artificial teeth that do not conform to the anatomy of
Oblique Ridge --
The transverse ridge of enamel which crosses the occlusal
surface of the upper molars from mesiolingual to distofacial.
A prosthesis used to close an abnormal opening between
the oral and nasal cavities.
Occipital Bone --
The bone which forms the posterior portion of the skull.
To bring together to bring the maxillary and mandibular
Occlusal Equilibration --
The process of refining and perfecting the occlusion.
This term is usually confined to the natural occlusion.
Occlusal Plane --
The plane established by the occlusal surfaces of the
bicuspids and molars of both the upper and lower jaws in opposition. May also
refer to the same plane established in the occlusion rims.
Occlusal Rest --
The part of the clasp which lies on the occlusal surface
of the tooth.
Occlusal Stop --
See occlusal rest.
Occlusal Surface --
The biting, grinding, or chewing surfaces of molars and
The contact relation and interdigitation of the maxillary
and mandibular teeth.
Occlusion Rim --
The built- up wax attached to the baseplate to establish
measurements of the patient’s teeth which are positioned in the occlusion
rim during the setup.
Covering the metal work of a prosthesis with a material
so that it does not show through a thin veneer of acrylic resin or porcelain.
Open Bite --
Increased interarch distance.
Orientation of Occlusal Plane --
Location of the position which the occlusal plane is to
occupy between the upper and lower ridges.
Oven, Burnout --
The gas or electric furnace used to eliminate the wax
pattern from the investment mold.
Ovoid Arch Form --
A dental arch which is oval or round in outline.
To combine with oxygen; for example, iron rust or brass
Oxyacetylene Torch --
A blow torch which mixes acetylene gas and pure oxygen to
produce a hotter flame than either gas and air or acetylene and air.
Packing of a Denture --
Placing the acrylic dough in the mold and closing the
Palatal Bar --
The metal piece or major connector contoured to the
palatal tissue and used to connect the right and left side of an upper
removable partial denture.
Palatal Bone --
Paired bones that form the posterior portion of the hard
The roof of the mouth.
A white, waxy hydrocarbon distilled from coal or
petroleum, used in the compounding of several dental waxes.
Parietal Bone --
The two quadrilateral bones which form the sides of the
The state of rest which the clasp of a partial denture
should assume when it is in place on the abutment tooth.
Passavent’s Cushion or Pad --
A small bulge of soft tissue found on the posterior and
lateral walls of the nasopharynx at the level of the soft palate. It aids in
closing the opening between the nasal and oral cavities in swallowing.
Path of Insertion --
The route traversed by a removable partial denture as it
is inserted or removed from the teeth. It is always parallel to the spindle of
Pennyweight (dwt) --
One- twentieth of a troy ounce; 24 grains equal 1 dwt.
Around the apex or root tip.
Periodontal Membrane --
The fibers between the alveolar bone and the tooth that
holds the tooth in the socket.
That branch of dentistry which deals with the science and
treatment of periodontal diseases.
Collectively, the tissues which surround and support the
The tough fibrous membrane which covers the outer surface
of all bone.
Peripheral Roll --
The outer border of an impression or denture formed by
the lip and cheek muscles. It does not include the posterior palatal seal.
The circumference or outer border of an object; for
example, a denture border.
Permanent Teeth --
The secondary or adult teeth.
In denture wearing, it refers to the patient’s ability
to say "S" and "CH" clearly with the appliance in place.
A study of the functions and activities of the body.
Removal of oxides from the surface of a gold alloy by
heating in an acid or other pickling agent.
The intermediate or middle abutment in a fixed partial
denture of three abutments. In a fixed partial, extending from cuspid to
second molar with the second bicuspid present, the second bicuspid would be
A finely ground powder used to impart color to a
A thin cast inlay which depends on small parallel pins
for retention. The pins are cast into the inlay and fit into small holes
prepared in the tooth.
A pointed depression on the surface of a tooth. A pit
occurs most often at points where several developmental lines meet, as on the
occlusal surface of molars. Also, they are found at the end of the buccal
grooves of molars.
Plaster Index --
Plaster used to register the position of a tooth, or
teeth, by recording the surfaces of the teeth in soft plaster.
Plaster of Paris --
Gypsum refined by grinding and heating.
Point Angle --
The angle made on a tooth by the convergence of three
surfaces at a point.
Polishing Agents --
Materials which impart a luster to a surface.
Methyl methacrylate powder.
The reaction which takes place between the powder and
liquid during the curing of acrylic resin.
That part of a fixed partial denture suspended between
the abutments which replaces a missing tooth or teeth.
A tooth- colored, sand- like material consisting mainly
of kaolin, feldspar, and flux. It fuses at high temperature to form a hard
substance much like enamel in appearance. It is used for inlays, jacket
crowns, denture teeth, fixed partial denture pontics, and complete crown
Pitted, not dense, containing voids and bubbles.
The upright metal rod which extends into a tube tooth to
retain it. In restorative dentistry, the metal projection of a crown that
extends into the root of a pulpless tooth.
Posterior Palatal Seal (Postdam) --
An elevation of acrylic resin on the tissue side of the
posterior border of an upper denture for the purpose of sealing the denture
against the resilient soft tissue in the palate.
Posterior Tilt --
Tipping of the cast to be surveyed so that the posterior
part of the cast is lower than the anterior part.
Posterior Tooth --
A tooth (bicuspid or molar) having an occlusal surface.
Precious Metal --
A metal that is highly resistant to corrosion and
oxidation. Gold and platinum are examples.
Precision Attachment --
A specially machined male or female part used in some
removable partial dentures for attachment of the appliance to the abutment
Preliminary Impression --
The first impression. A cast is poured and an individual
tray is made for the final impression.
Primary Stress-Bearing Area --
An area of the mouth suited to withstand heavy stress
from the denture.
To cure a denture.
A forecast of the probable outcome of an illness.
In dentistry, the removal of calculus and stains from the
Proportional Limit --
The amount of stress a metal will stand before it is
permanently stretched or bent. It is a measure of strength and toughness of an
Plural of prosthesis.
An artificial replacement for a lost part, In dentistry,
it is used in the more limited sense of strictly dental replacement.
Prosthetic Dentistry --
The art and science of replacing missing natural teeth
and associated tissues with fixed or removable artificial substitutes for the
purpose of restoration and maintenance of oral function, health, comfort, and
appearance. Prosthodontic practice also includes application or prescription
of proper medicinal.
A projecting part.
To project forward.
Protrusive Registration --
Contact relation of the upper and lower teeth when the
mandible is brought forward with the anteriors edge to edge.
Proximal Surface --
The surface of a tooth which lies next to another tooth.
Pterygomaxillary Notch --
The notch formed by the junction of pterygoid hamulus of
the sphenoid bone and the maxilla. See hamular notch.
The connective tissue found in the pulp chamber and
canals. It is made up of arteries, veins, nerves, and lymph tissue.
An abrasive agent used in many polishing procedures.
One- fourth of the mouth. One- half of either arch.
To plunge a hot casting into water. This will soften most
Quick Cure Resh --
Autopolymerizing acrylic resin.
The ascending part of the mandible.
Reciprocal Arm or Bracing Arm --
The rigid arm of the clasp so located on the tooth as to
oppose any pressure exerted by the retentive arm. It acts to stabilize the
appliance and resist lateral displacement.
The principle in clasping which holds that each force on
a tooth must be balanced by an equal and opposite force to prevent movement of
Reducing Flame --
The part of the blowpipe or Bunsen flame least apt to
cause oxidation of the metal when melting or soldering.
Reducing Investment --
A specially made investment which contains fine graphite
or copper particles to prevent oxidation of the casting.
Refractory Cast --
A cast made of a heat resisting material. See investment
Material added to a cast for the purpose of relieving the
pressure over hard areas in the mouth. Also, added to the master cast before
duplicating to create a raised area on the refractory cast. Also, the scraping
of a working cast to better fit a facing to the ridge.
Replacement of the tissue surface of the denture to make
it fit more accurately.
Removable Partial Denture --
A dental prosthesis, which artificially replaces teeth
and associated structures in a partially edentulous dental arch, removed and
replaced by the patient.
A small bulb of wax attached to the sprue for the purpose
of providing additional molten metal when the casting begins to solidify and
A gummy substance obtained from various trees. Resins are
used in making many dental materials.
Resin, Denture --
Methyl methacrylate, commonly referred to as acrylic
Wasting away of tooth or bone. The roots of the primary
teeth are resorbed naturally.
A metallic lug or projection of a removable partial
denture which lies on the occlusal or incisal surface of a tooth. Its
principal function is to resist vertical displacement of the clasp or
Rest Position --
The position of the mandible in which all the masticator
muscles are in a relaxed state.
Rest Seat Preparation --
The preparation made on a tooth to accommodate the
occlusal or incisal rest.
A component which acts to resist dislodgement. In
removable partial dentures, a clasp is referred to as a "direct
retainer." In fixed partial dentures, the abutment casting is a retainer.
Retention of a Clasp --
The property which enables it to resist dislodgment or
change of position.
Retromolar Pad --
The soft tissue pad at the posterior extremity of the
Reverse Curve --
A plane of occlusion which instead of forming the usual
compensating curve assumes an opposite downward curve.
Retrusion of the Mandible --
Backward movement of the mandible.
Reversible Hydrocolloid --
An impression material containing agar which can be
softened to a jelly- like consistency and cooled to a solid to make an
impression or duplicate a cast. This procedure can be repeated by reheating,
hence the name reversible.
In the shape of an equilateral parallelogram having its
angles oblique. The occlusal surfaces of the upper molars are rhomboidal in
A linear elevation of enamel on the surface of a tooth;
for example, a marginal ridge. Also, in prosthodontics, the alveolar ridge
which is the area of the upper and lower jaws formerly occupied by the natural
Ridge Contour --
The shape of the alveolar ridge with reference to its
height, width, and degree of slope.
Ridge Lap --
The area of an artificial tooth which normally overlaps
the alveolar ridge. It corresponds on the inner surface of the denture tooth,
approximately to the location of the collar on the facial surface.
Ridge Relation --
The position of the upper and lower ridges relative to
Ridge Resorption --
The resorption of the alveolar bone resulting in a
progressively flatter ridge.
Ring (Casting Ring) --
A metal cylinder used to confine the investment when
investing the pattern for a crown, onlay, inlay, or removable partial denture
Roach Clasp or Bar Clasp, Vertical Projection Clasp --
A type of removable partial denture clasp which
approaches the survey line of the tooth from below.
Rockwell Hardness --
A method of measuring the hardness of metals which are
too hard for the Brinell needle.
The portion of the tooth that is covered with cementum.
Root Canal --
The small channel which runs through the tooth root.
Connecting the pulp chamber and the root end opening.
Rouge (Jeweler’s Rouge) --
A red powder, usually in cake form, used on a buff or
chamois wheel to impart a high luster to metal or acrylic resin.
The elevated folds or wrinkles of soft tissue situated in
the anterior part of the palate.
Safeside Disc --
An abrasive disc having one smooth side so that it will
not damage or scratch adjacent surfaces or structures.
Sagittal Plane (Mid) --
The plane that divides the body vertically into two equal
Sandpaper Disc --
Various sized discs with different grits of sandpaper on
their surface used for smoothing and polishing in the laboratory.
Sanitary Pontic --
A conical type of artificial tooth contoured so that the
tongue and cheeks can keep it clean.
Saturated Calcium Sulfate Dihydrate Solution (SDS) --
A clear solution of water and a maximum amount of
dissolved gypsum product. Also known as slurry water.
Secondary Stress Bearing Area --
An area of the mouth used, but not ideally suited, for
bearing part of the load caused by a denture.
Second Half-Flasking --
Completion of the investing process in the top half of
the denture flask.
Semirigid Fixed Partial Denture or Broken-Stress Fixed
Partial Denture --
A fixed partial denture in which one of the connections
between the units is a joint which allows some movement instead of the usual
Separating Medium --
An agent used between two surfaces to prevent them from
Indented with many shallow crosscuts; toothed like a saw
blade; for example, serrated pliers.
Setting Expansion --
The increase in size which takes place in a mass of
gypsum material as it hardens.
Setting Time --
The time necessary to harden or solidify.
Setup (noun) --
A broad term usually denoting an upper and lower
arrangement of teeth in wax.
Set Up (verb) --
The act of arranging and positioning artificial teeth in
a complete or partial denture.
A degree of intensity of color.
Shelf Life --
The period of time for which a material can be stored
without losing its useful properties.
Shellac Resin --
A compound composed of wax collected from a tropical
tree, to which various fillers are added. It is manufactured in the form of
wafers for trial baseplates.
A fluid mixture of a liquid and undissolved solid.
Small Interarch Distance --
A small distance between the maxillary and the mandibular
Soft Palate --
The posterior one- third of the roof of the mouth
composed largely of moveable soft tissue.
To join two metals with a third metal by heating.
Soldering Pliers --
Pincer-like instrument used to pickup the solder and
place it in the joint during soldering operations. Same as soldering tweezers
Capable of being dissolved.
In a solution, the dissolved substance is called the
solute. In salt water, the water is the solvent and the salt is the solute.
A substance that is capable of dissolving another
substance. Water is a solvent for salt.
An instrument designed for mixing cement on a slab. A
flat, knife- like instrument used for mixing plaster, Hydrocal, and
investment. An instrument which can be heated for working with wax.
Specific Gravity --
The weight of a substance as compared to the weight of
exactly the same volume of water. The standard used is that 1 cc of water at 4
o C equals 1.
Sphenoid Bone --
The irregular wedge- shaped bone at the base of the
Spindle, Surveyor --
The perpendicular part of the surveyor which contains a
chuck that holds the interchangeable tools.
An appliance of metal or acrylic made to hold parts
together. Periodontal splints are made to hold loose teeth. Fracture splints
are made to hold two pieces of broken bone in correct alignment.
Splint Remounting Plate --
An device which consists of two machined metal plates.
One part is embedded in the cast and the other into the articulator mounting.
The cast can then be removed from the mounting and accurately replaced.
A cylinder of metal or wax attached to the wax pattern of
an onlay, crown, or removable partial denture, which later is withdrawn or
removed from the investment, leaving a passage into the mold.
Sprue Base --
The cone- shaped device used to hold the sprue pin for
inlay casting or the main sprue for partial denture casting.
Square Arch Form --
A dental arch roughly square in outline, particularly in
the anterior region.
The property of resistance to tipping and rocking of a
Stabilized Baseplate --
A baseplate lined with an impression material to increase
A plaster- like substance, the grains of which are much
less porous than those of plaster. It makes a denser, more durable cast than
Stone Cap --
See stone core.
Stone Core --
The layer of stone placed over the incisal and occlusal
surfaces of the teeth in the top half of the flask to facilitate deflasking.
The deformation of a material caused by an external
The forces within a substance which oppose an external
Stress Breaker --
A device incorporated into a removable or fixed partial
denture to reduce the stress on the abutment tooth by allowing some movement
of the joint.
A minor connector is sometimes referred to as a strut.
Under the tongue.
Sulcus (On a Tooth) --
A linear depression on the surface of a tooth, the slopes
of which meet at an angle. A sulcus is always found along the surface of a
Sulfuric Acid --
An acid made up of oxygen, sulfur, and oxygen. Mixed with
water in equal parts, it is used as a pickling solution for gold.
Supernumerary Tooth --
An extra tooth, one in excess of the normal number.
Resistance to displacement in a vertical direction or in
a direction parallel to the long axis of the teeth if they are present.
The area above the survey line on an abutment tooth.
Suprabulge Clasps --
See circumferential- type clasps.
Surgical Guide or Template --
The translucent acrylic tray used in immediate denture
fabrication at the time of extraction and insertion of the immediate denture,
to disclose to the oral surgeon the areas which need trimming.
Analyzing the master cast for favorable and unfavorable
undercut conditions. Establishing the path of insertion by means of a dental
An instrument used to locate and mark the greatest
circumference of one or several abutment teeth at a given tilt of the cast.
Also, used to locate soft tissue undercuts at a given tilt.
Suture Line --
A junction line where the bones of the cranium unite.
To shape a piece of metal between a die and counterdie.
Symphysis, Mandibular --
The external ridge of bone on the facial surface of the
mandible at the midline.
The connector between the clasp body and the frame of the
Tapered Arch Form --
A dental arch which is in between an oval and a square
arch form in outline.
Tapered Blockout Tool --
The tapered, cylindrical- shaped surveyor tool used to
carve the undercut wax on the proximal surface of an abutment tooth on the
master cast. The purpose of the taper is to ensure that the rigid part of the
metal framework does not enter an undercut adjacent to an edentulous space.
A vertical projection- type clasp formed approximately in
the shape of a "T."
The procedure of imparting a desired degree of hardness
to a metal. Also called heat hardening.
A flat or curved plate usually of metal used as a guide
in arranging artificial teeth.
Temporal Bone --
The irregular- shaped bone at the side and base of the
Temporomandibular Joint --
The joint formed by the condyle of the mandible and the
Heavy fibrous bundles that attach a muscle to bone.
Tensile Strength --
A measure of resistance to breakage from a stretching or
Thermal Expansion --
The increase in size of a substance when it is heated.
Materials that soften under heat and solidify when they
are cooled without chemical change.
Thirty Degree (30°) Teeth --
An anatomical type of artificial posterior tooth. The
cusp incline forms a 30° angle with a horizontal plane.
Three-Quarter Veneer --
A crown covering all surfaces of an anterior tooth except
the labial. A posterior three- quarter crown may cover all the surfaces of an
maxillary tooth except the buccal or all the surfaces of a mandibular tooth
except the lingual.
Trade name for chrome alloy characterized by a lower
melting point than any of the other chrome dental alloys.
The position of the cast on the surveyor table relative
to a horizontal plane.
A partial denture is tissue-borne when the masticator
stresses are borne by the soft tissue of the mouth.
A partial denture is tooth- borne when the masticator
forces are carried by the abutment teeth.
A twisting force.
Torus Mandibularis --
An abnormal bony eminence found on the lingual surface of
the body of the mandible. There may be several, usually in the area of the
midline backward to about the bicuspids.
Torus Palatinus --
An abnormal bony eminence on the hard palate.
Transfer Coping --
A metal or plastic cap used to seat a die in an
Transverse Ridge --
The ridge of enamel formed at the junction of buccal and
lingual ridges on the occlusal surface of a molar or bicuspid.
A four- sided plane figure with two parallel sides. The
occlusal surface of the lower first molar is trapezoidal in outline.
A wound or injury produced by physical impact.
Treatment Partial --
A horseshoe- shaped acrylic partial which temporarily
replaces one or two teeth.
Treatment Plan --
An outline of the various clinical steps in proper
sequence to be followed in restoring a mouth to health and function.
Trial Baseplate --
The temporary foundation which is used to establish
certain measurements of the patient and upon which teeth are arranged and
tried in the mouth. It consists of the baseplate and occlusal rim.
Trial Packing --
The process of filling the mold with acrylic resin dough
several successive times before the final closure to ensure an adequate amount
of the material is present.
Triangular Ridge --
The ridge of enamel which extends from the tip of the
cusp down onto the occlusal surface of bicuspids and molars.
Having three roots.
Troy Weight --
The system of weights used in dentistry for weighing
gold. The basic unit is the grain; 24 grains equal 1 pennyweight (dwt).
The process of checking the trial denture in the
patient’s mouth for accuracy as well as the suitability and arrangement of
A nodule or small eminence.
The area at the posterior end of the maxillary alveolar
ridge in the form of a bulge.
Tube Tooth --
An artificial tooth containing a vertical channel which
fits over a metal post and secures the tooth to the appliance.
Twenty Degree (20°) Teeth --
A trade name denoting artificial posterior teeth with
cusp angles at 200.
Any area of the master cast below the survey line which
may affect insertion or removal of a prosthesis.
Undercut Gauge --
A tool for the surveyor shaped so that it will measure
the amount of undercut on a tooth in thousandths of an inch.
Undesirable Undercut --
An area on the cast below the survey line which cannot be
used for retention and which may interfere with insertion and removal of the
removable partial denture.
Vacuum Fired --
Baking a porcelain in a vacuum.
Vacuum Mixing --
A method of mixing a gypsum material in a vacuum.
The palate or roof of the mouth.
A thin layer.
Vertical Overlap --
The extension of the upper teeth over the lower teeth in
a vertical direction.
That part of the mouth between the cheeks or lips and the
Vibrating Line --
A line in the soft palate that marks the junction between
tissue which moves, as in swallowing, and that which is stationary.
A mechanical device used to remove air pockets from a mix
of plaster or stone.
Vicker’s Hardness --
A range of hardness measured by the indentation made by a
square- based, pyramidal diamond point under various loads.
A measure of a liquid’s resistance to flow or its
A stage in the firing of a porcelain restoration. The
state of complete fusion of the porcelain.
The ability to become gaseous or to vaporize into gas.
The unit of electrical pressure which forces the current
through the circuit.
The bone which forms the lower and posterior portions of
the septum of the nose.
Loss of original shape or contour.
A unit of electrical power. It is obtained by multiplying
the voltage by the amperage.
Many different types of waxes are used in dentistry. Each
is compounded to produce certain physical properties for a specific purpose.
Waxes are manufactured in various forms such as baseplate, boxing, inlay, and
Wax Elimination --
Removal of the wax pattern from the mold by heat.
Wax Pattern --
Wax which has been formed into the size and shape desired
in the finished prosthesis and which is used to form the mold in the
Waxup (noun) --
The finished wax pattern for any dental prosthesis.
Wax Up (verb) --
To smooth and finish the wax on a complete denture. To
carve a wax pattern for a fixed prosthetic unit. To contour the wax for any
A process for joining metals using heat and pressure, or
pressure alone, as with gold foil.
Working Cast --
The cast of a whole mouth or section of a mouth upon
which the laboratory work is accomplished.
Dryness of the mouth from lack of a normal amount of
Yield Strength --
The amount of stress a metal or alloy will withstand
before it is permanently deformed.
Zinc Oxide --
A powder incorporated with eugenol or a similar oil to
form a mold antiseptic and analgesic paste. It is a constituent of most
Zygomatic Processes (Temporal and Maxillary) --
The bony extensions of the temporal and maxillary bones
which unite with the zygomatic bone to form the zygomatic arch.