Abbreviations and Acronyms
BBC.buffing bar compound
cm3.cubic centimeter
cm.centimeters
DI.disto-incisal
dwt.penny weight
EDM.electric discharge machine
FPD.fixed partial denture
g/cc.grams per cubic centimeter
gr.grain
lb.pound
MID.mesio-incisal-distal
MI.maximum intercuspation
ml.milliliter
mm.millimeter
MOD.mesio-occlusal-distal
MO.mesio-occlusal
OSHA.Occupational Safety and Health Administration
oz.ounce
PMEL.precision measurement evaluation laboratory
psi.pounds per square inch
RPD.removable partial denture
rpm.revolutions per minute
SDS.saturated calcium sulphate dihydrate solution
Terms
abrasive.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.
absorption.Taking up a substance into the mass of another.

abutment.
1. On RPDs, it is the tooth on which a clasp is placed to support and retain the removable partial
denture.
2. On fixed partial dentures, it is the tooth to which the retainer is cemented.
3. On implants, it is the part that supports and/or retains the prosthesis.
accelerator.A substance that speeds up a chemical reaction.
acid.Any one of a group of corrosive chemicals used to clean oxide layers or surface contaminants
from gold castings.
acid etching.
1. In clinical dentistry, treating the enamel, generally with phosphoric acid, by removing
approximately 40 microns of rod cross-section for resin retention.
2. As a laboratory procedure, using electrolysis or chemicals to remove a microscopic layer of
metal to produce mechanical retention for resin bonding. (Do not confuse with electropolishing,
which occurs to a much greater degree.)
acrylic resin.A plastic widely used in dentistry for making denture bases, provisional crowns, custom
trays, etc.
acrylic resin impression tray.See custom tray.
acrylic resin veneer.A tooth-colored layer of plastic placed over the facial surface of a metal crown to
improve the crown¡¯s appearance.
ADA Specification.A detailed description of the qualities and properties required of a dental material
as set forward by the American Dental Association (ADA).
adhesion.The sticking together of unlike substances.
adjustment.A modification to a dental prosthesis to enhance fit, function, or appearance.
agar.A gelatin-like substance obtained from certain seaweeds (algae) and used in compounding
reversible hydrocolloid impression materials.
Aker¡¯s clasp.See circumferential clasp.
alginate.An irreversible type of hydrocolloid made from a salt of alginic acid.
align.To properly position in relation to another object or objects.
alloy.A metal consisting of a mixture of two or more pure metals.
alveolar process.Part of the mandible and maxilla that surrounds and supports the roots of natural
teeth.
alveolus.The bony socket holding the root of a tooth by the periodontal ligament.
amalgam.An alloy of mercury, silver, and other metals used as a restorative material.
amorphous.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 degrees or more.
anneal.To heat a metal, followed by a controlled cooling to remove internal stresses and create a
desired degree of toughness, temper, or softness to the metal.
anode.The positive pole of an electric source.
anterior guidance.See mutually protected articulation.
anterior guide pin.The pin fitting into the upper member of the articulator, resting on the anterior
guide table, that maintains a selected amount of vertical separation. Also called incisal guide pin.
anterior guide table.Component of the articulator on which the anterior guide pin rests to maintain
occlusal vertical dimension and influence articulator movements. Also called incisal guide table.
anterior teeth.The central and lateral incisors and the cuspids of either arch.
anterior tilt.A term used in surveying the master cast; when the cast is tipped on the surveyor table so
the anterior part of the cast is lower than the posterior.

anteroposterior.Extending from the front, backward.
anteroposterior curve.The anatomic curve established by the occlusal alignment of the teeth, from
the cuspid through the buccal cusps of the posterior teeth, when viewed from the side. Also called the
curve of Spee.
antiseptic.Chemical agent applied to tissue to inhibit growth of microorganisms.
apical.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.
approach arm.The part of a bar clasp connecting the retentive portion to a removable partial denture
framework.
aqua regia.A mixture of three parts hydrochloric acid and one part nitric acid. Used for removing a
layer of gold.
arch.See dental 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.
arcon articulator.An articulator having the condyle elements attached to the lower member in the
same way condyles are an anatomic feature of the mandible in a human skull.
arrangement.See tooth arrangement.
arrow point (gothic arch angle).On an articulator, the pointed pattern made by the intersecting
working and balancing paths of a stamp cusp as it travels out of maximum intercuspation. The
maximum intercuspation (MI) position is the apex of the arrow.
articular disc.The circular-shaped, flat piece of fibrocartilage lying between the condyle of the
mandible and the glenoid fossa of the temporal bone.
articulating paper.Colored paper or film, usually supplied in strips, used intraorally and in the
laboratory to detect contact between the maxillary and mandibular teeth.
articulation.
1. The place of union or junction of two or more bones of the skeleton.
2. In dentistry, the contact relationship between the occlusal surfaces of the teeth during function.
articulator.A mechanical device representing the temporomandibular joints and jaws to which
maxillary and mandibualr casts can be attached for performing prosthodontic procedures.
artificial stone.See dental stone.
asbestos substitute.A strip used to line a casting ring used to invest fixed prosthodontic units;
replaced asbestos strips.
asepsis.A pathogen-free condition.
attrition.The wearing away of the biting surfaces of the teeth.
autogenous glaze.A natural glaze.
autopolymerizing resin.Resin whose polymerization is initiated by a chemical activator.
auxiliary lingual bar.An extension from the lingual bar of a mandibular RPD framework used to
stabilize loose, periodontally involved anterior teeth. Also called a supplemental Kennedy bar.
axial.Lines, walls, or surfaces parallel with the long axis of a tooth.
axis.An imaginary line passing through a body, around which the body may rotate; for example,
transverse horizontal axis.
axis orbital plane.The horizontal plane established by the transverse horizontal axis of the mandible
with a point on the inferior border of the right or left bony orbit (orbitale). Can be used as a horizontal
reference point; corresponds to the Frankfort plane.
backing.The metal plate constructed to fit the slot or pins of the porcelain facing. May be cast in the
laboratory or manufactured.

balanced articulation.The bilateral, simultaneous, anterior, and posterior occlusal contact of teeth in
centric and eccentric positions. Also called balanced occlusion.
balanced occlusion.See balanced articulation.
balancing side.See nonworking side.
balancing side occlusal contacts.See nonworking side occlusal contacts.
bar.A major connector used in RPD construction to connect the right and left sides of the framework.
bar clasp.A type of clasp in which the retentive tip approaches the undercut from below the survey
line. Also called infrabulge clasp.
basal seat area.See denture foundation area.
base.The part of a removable prosthesis that retains artificial teeth and replaces the alveolar process
and gingival tissues. The base of a removable prosthesis is made of metal or denture resin.
base metal.Any metal element that doesn¡¯t resist tarnish and corrosion. Any metal that is not noble.
baseplate.See record base.
baseplate wax.A hard, pink wax used for making occlusion rims, waxing dentures, and many other
dental procedures.
beading.
1. As in ¡°beading a cast,¡± to score a cast in any desired area to provide a seal between the finished
prosthesis and the soft tissue.
2. As in ¡°beading an impression,¡± to rim an impression with a wax strip before pouring so all
critical impression landmarks show up in the cast.
bead line.The indentation resulting from beading the cast.
beeswax.The wax derived from the bee¡¯s honeycomb; used in many dental waxes.
Bennett Movement.See laterotrusion.
bicuspid or premolar.A tooth having two cusps.
bifurcated.(forked) Having two roots.
bilateral.Having two sides. Any RPD having a major connector is called a bilateral appliance.
biocidal.Destructive to living organisms.
biteplane.See occlusal plane.
blind vent.See chill set.
block out.The process of eliminating undesirable undercut areas of a cast or denture. Most frequently
used in preparing a cast for RPD 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 master casts.
blow torch.A device designed to mix gas and air so it can be ignited. The flame is directed on an
object to heat or melt the object.
body of a clasp.Connects rest and clasp arms to the minor connector.
boiling point.The temperature at which the vapor pressure of a liquid is equal to the external pressure.
Boley gauge.A caliper-like instrument calibrated in millimeters and used for fine measurements in the
laboratory.
bolus.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.Wax wrapped around the impression for confining the dental stone as the cast
is poured.
boxing wax.A pliable wax in strip form, used to box an impression.
bracing.The resistance to displacement in a lateral direction from masticatory forces.

bracing arm.See reciprocal arm.
brass.An alloy of about 60 to 70 percent copper; the remainder is zinc.
bridge.See fixed partial denture.
Brinell hardness.An index number denoting the relative surface hardness of a material, usually
abbreviated ¡°Bhn.¡± Used in testing softer metals and nonbrittle materials such as gold, copper, and
silver.
broken stress fixed partial denture.See interlock fixed partial denture.
bruxism.A clenching of the teeth accompanied by lateral motion in other than chewing movements of
the mandible. Grinding or gritting of the teeth usually during sleep or nervous tension. Causes excessive
wear of occlusal surfaces.
buccal.Pertaining to the cheek. The surface of the tooth toward the cheek.
buccal frenum.A connecting fold of membrane attaching the cheeks to the alveolar ridge in the
bicuspid region of each arch. (plural: buccal frena)
buccal groove.Landmark on the buccal surfaces of mandibular molars, extending vertically from the
occlusal surface down toward the cemento-enamel junction.
buccal notch.The V-shaped notch in the impression or denture formed by or for the buccal frenum.
buccinator muscle.The cheek muscle.
buff.To polish by rubbing or by holding the object against a revolving felt wheel impregnated with a
polishing agent.
bur.A small rotating instrument used in the dental hand piece for cutting acrylic resin or metal. Also
used by the dentist to cut enamel or dentin.
burlew discs.The rubber wheels impregnated with pumice, used for polishing dental restorations.
burn out.See wax elimination.
burn out temperature.The temperature that must be reached to properly eliminate a wax pattern from
the mold and expand the mold.
burnish.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.
butt joint.A type of joint in which the two pieces to be joined touch each other, but do not overlap.
calculus.The hard calcium-like deposit that forms on teeth and on artificial dentures.
cameo surface.The viewable portion of the denture. The part of the denture base normally polished.
Includes the facial and lingual surfaces of the teeth.
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.
canine.A tooth having one cusp or point; the third tooth from the midline. So named because it
corresponds to the long teeth of a dog. Also called a cuspid.
canine or cuspid eminence.The prominence of labial bone that overlies the root of the upper canine
canine guided articulation.A form of mutually protected articulation in which the canines disengage
the posterior teeth during an excursive mandibular movement. Also called cuspid guidance.
cantilever fixed partial denture.A fixed partial denture supported on only one end with one or more
abutments.
cap.A term used for the top of a denture flask.
capillary attraction.The characteristic by which, because of surface tension, 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.

carborundum.A trade name for silicon carbide. Extremely hard blue crystals used as an abrasive in
many dental stones and points.
caries.Tooth decay.
carnauba wax.A type of wax obtained from the South American palm tree used in some dental
materials.
cast.
1. The positive reproduction of the mouth in stone or similar material on which a prosthetic
appliance can be constructed.
2. To produce a shape by thrusting a molten liquid into a mold possessing the desired shape.
cast base.The portion of the removable prosthesis covering the edentulous ridges and supporting
artificial teeth; made of metal. Also called metal base denture.
casting.
1. An object formed in a mold
2. The process of forming a casting in a mold.
casting machine.A device designed to hold the investment mold and melted metal that has the
capability of forcing the melted metal into the mold by either centrifugal force, air pressure, or vacuum.
catalyst.A substance that accelerates a chemical reaction without affecting the physical properties of
the material involved.
cathode.The negative pole of a source of electric current.
cement.Dental luting agents with the dual purpose of holding the casting on a tooth and protecting the
pulp against thermal shock.
cementum.A soft, bone-like structure covering the root surface of the tooth.
centigrade.A heat measuring scale calibrated so the freezing temperature of water is 0 degrees and the
boiling temperature of water is 100 degrees.
centimeter.A hundredth of a meter; 2.54 centimeters equals 1 inch.
central fossa.The rounded, relatively shallow depression found in molars in the approximate middle
of the occlusal surface.
centric occlusion.The occlusion of teeth when the mandible is in centric relation; may or may not
coincide with MI.
centric relation.A maxillomandibular relationship in which the condyles articulate with their
respective discs in the anterior-superior position of the glenoid fossa against the articular eminences.
centrifugal.A force in a direction from the center, outward.
centripetal.A force in a direction from the periphery toward the center; the opposite of centrifugal.
ceramic.Having to do with the use of porcelain.
ceramic crown.A ceramic restoration restoring a clinical crown without a supporting metal
substructure.
ceramo-metal.See metal ceramic restoration.
ceresin.A mineral wax often used as a substitute for beeswax.
cervical.Pertaining to the neck of a tooth.
cervical line.The line where the cementum and enamel join. Also known as the cementoenamel
junction.
cervix.The neck of a tooth.
chalk.Calcium carbonate. A powder used for final polishing.

characterization.
1. (Dentures) Anything done to a denture to make it look natural, including staining the denture
base, making special tooth arrangements, and staining the denture teeth.
2. (Metal ceramic restorations) Staining and/or modifying the surface texture and shape to make the
restoration look natural.
checked tooth.A tooth with a hairline crack.
chewing cycle.See masticatory cycle
chill set.A riser or vent that does not extend outside the mold.
Christensen¡¯s phonemenon.The space occurring between opposing occlusal surfaces during
mandibular protrusion. Occuring because of disclusion of posterior teeth in protrusion due to condylar
guidance.
chroma.Saturation of a hue.
chuck.The lathe attachment that grips the various burs, abrasive wheels, or buffing wheels.
circumferential clasp.A clasp that approaches the undercut portion of a tooth from above the survey
line.
clasp.The part of RPD that partly encircles the abutment tooth and helps to retain, support, and
stabilize the appliance.
clasp arms.The shoulders and tips of a clasp; the part of the clasp that extends from the body out to
the tip.
clasp shoulder.The part of the clasp arm that connects the body to the retentive terminal; the portion
of the clasp arm closest to the body.
cleft palate.An opening in the palate in the hard or soft palate or in both. An acquired cleft palate is
caused by surgery, disease, or accident. A congenital cleft palate is present at birth.
clinical crown.That part of a crown visible in the mouth above the gum line.
closed bite.Slang for decreased occlusal vertical dimension.
coalescence.The result of firing porcelain at an extremely high temperature.
cohesion.The molecular attraction by which the particles of a body are united throughout their mass.
cold cure.The polymerization of acrylic resins at room temperature. See autopolymerizing resin.
cold flow.A change in shape or dimension at a temperature lower than the normal softening point of
the material.
collar.The neck of an artificial tooth below the cervical line used to embed and retain the tooth in a
denture base.
combination clasp.A circumferential clasp assembly having one cast arm and one wrought wire arm.
compensating curve.The combination of the two curves made when the denture teeth are set on
anteroposterior and lateral curves for purposes of achieving a balanced articulation.
complete denture.A dental prosthesis replacing all natural dentition and the associated structures of
the maxilla or mandible.
compression molding.The method of denture molding employing a two-piece split mold. Acrylic
resin dough is placed between the two halves of the mold, compressed, and cured under pressure.
concave.Curving inward; dished in.
condensation.The process of making a substance more compact.
conductivity.The property of conducting heat or electricity. Silver and copper are two of the best
conductors.
condylar guidance.A device on an articulator intended to produce guidance in the articulator¡¯s
movements similar to that produced by the paths of the condyles in the temporomandibular joints.
condylar guide inclination.The angle formed by the inclination of a condylar guidecontrol surface of
an articulator to a specified reference plane; for example, horizontal condylar guide inclination.

condylar indication.The scale on the articulator measuring the amount of condylar inclination.
condylar path.The path of the mandibular condyle in the temporomandibular joint during mandibular
movement.
condyle.The rounded articular surface at the articular end of a bone. In the temporomandibular joint, it
is football shaped and found on the end of the condyloid process of the mandible.
condyle head.See condyle.
congenital.A condition occurring in the offspring before birth.
connective tissues.The tissues that bind together and support the various structures of the body.
connector.
1. In RPDs, a part of the framework that serves to connect two parts with another. Connectors are
divided into major and minor.
2. In fixed prosthodontics, the portion of a fixed partial that connecting the retainers and the
pontics.
contact surface.The area on a tooth touching an adjacent tooth. Normally found on both mesial and
distal surfaces of all teeth except the third molars. Also called contact area.
continuous bar connector.A type of lower RPD that employs a second or auxilliary bar with a lingual
bar. Also called a continuous bar retainer and double lingual bar.
contour.
1. (noun) The shape of a surface.
2. (verb) To shape into a desired form.
convex.A surface curved outward toward the viewer.
cope.The upper half of a denture flask.
coping.A thin covering or crown.
copper band.The hollow cylinders of thin copper in various diameters used to make impressions for
crowns and inlays.
coronal.Pertaining to the crown portion of a tooth.
creep.To change shape permanently due to prolonged stress or exposure to high temperatures.
crest of the ridge.The high point of the alveolar ridge.
crossbite.See reverse articulation.
cross-section.A cut section of an object made so the cut is perpendicular to the object¡¯s long axis.
crown.
1. In anatomy, the part of the tooth covered by enamel.
2. In the laboratory, an artificial replacement that restores missing tooth structure with a metal or
ceramic restoration.
crucible.The heat resistant container used to hold the metal while it is melted in preparation for
casting.
crucible former.The device used to hold the sprued wax pattern upright in the casting ring when it is
invested. Shaped to form a funnel for the gold as it enters the mold. Sometimes erroneously called a
sprue former.
crushing strength.The amount of pressure required to crumble or crush a material.
crystallization.The solidification of a gaseous or liquid substance.
cure of denture.See polymerization.
Curve of Spee.See anteroposterior curve.
cusp.A cone-shaped elevation on the occlusal surface of a molar or bicuspid and on the incisal edge of
the cuspid.
cuspid.See canine.

cuspid line.The vertical line the dentist scribes on the record rims to indicate the position the cuspid is
to occupy in the setup.
custom tray.An impression tray made on a preliminary cast used to make the final impression.
cyanoacrylate.A quick setting adhesive. Also called super glue.
dappen dish.A glass medicine dish.
debubblizer.A wetting agent used to lower surface tension of the water in an investment so it flows
more easily over the wax pattern.
decalcification.The loss or removal of calcium salts from calcified tissues. Characterized by areas of
white, splotchy opacity on the surfaces of teeth.
deciduous tooth.A tooth that will be replaced by a permanent tooth.
decreased occlusal vertical dimension.A reduction in the distance between two points when the teeth
are in occlusal contact. Also called closed bite.
deflask.The removal of the denture from the mold in the flask.
dehydrate.To remove the moisture from a substance.
density.The mass of a substance per unit volume.
dental arch.A term given to the horseshoe-like arrangement of either the upper or lower teeth or the
residual ridge.
dental implant.A prosthetic device implanted within the bone to provide retention and support for a
fixed or removable appliance.
dental plaster.A gypsum refined by grinding and heating.
dental stone.A specially calcined gypsum physically different from dental plaster in that the grains are
nonporous and the product is stronger.
dental wax.Any of the various waxes used in dentistry.
dental wrought wire.An alloy in wire form manufactured by drawing it through die plates of varying
diameters.
dentin.The tissue of the tooth underlying the enamel of the crown that makes up the bulk of the
substance of the tooth.
dentition.The natural teeth as a unit.
dentulous.With teeth; as opposed to edentulous (without teeth). Also called dentate.
denture.See complete denture.
denture base material.The material of which the denture is made; exclusive of the teeth.
denture border.
1. The margin of the denture base at the junction of the polished surface and the impression surface.
2. The peripheral border of a denture base at the facial, lingual, and posterior limits. Also called
peripheral roll.
denture foundation area.The surfaces of the oral structures available to support a denture.
denture staining.The process of adding pigments to the facial flange of the denture to more closely
simulate natural mouth tissue.
deoxidizing.To remove oxides from the surface of a gold alloy by heating the alloy in an acid or other
proprietary agent. Also called pickling.
deoxidizing investment.See reducing investment.
desiccate.To make dry; to remove all moisture.
desirable undercut.The part of an abutment tooth below the survey line that can be engaged by the
clasp tip to retain the RPD.
developmental groove.A groove formed by the union of two lobes during the development of the
crown of a tooth.
devitrification.To eliminate vitreous (glass) characteristics partly or wholly; to recrystallize.

diagnosis.The determination of the nature of the disease condition present in a patient.
diagnostic cast.A reproduction of the mouth for the purpose of study and treatment planning.
diamond point.Small mounted points impregnated with diamond particles, used in the dental hand
piece.
diastema.A space between the teeth.
diatoric.A channel placed in the denture tooth as a mechanical means of retaining it in the denture
base.
die.The positive reproduction of a prepared tooth in any suitable substance.
dimensional stability.The ability of a material to retain its size and form.
direct current.The 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 dentist.
direct retainer.The part of an RPD appliance designed to directly resist dislodgement; for example,
the clasp.
disc.A flat circular plate, usually impregnated with an abrasive agent, used in the laboratory to smooth
and polish. The abrasive agent may be silica, garnet, emery, or some other agent.
disclude.Separation of the maxillary and mandibular teeth.
disinfectant.An agent that kills infecting agents; for example, phenol.
distal.A surface facing away from the midline of the mouth; the distal surface of a tooth.
double lingual bar.See continuous bar connector.
dough.The moldable mixture formed by combining acrylic resin powder and liquid.
dovetail.A widened portion of a prepared cavity used to increase retention.
dowel.A post, usually made of metal, fitted into the prepared root canal of a natural tooth. Also called
post and core.
drag.A term for the lower half of a denture flask.
dry heat.The heat of a flame (as opposed to moist heat from a water bath).
ductility.The property of a metal that permits it to be drawn into a wire without breaking.
duplicate cast.A cast produced from an impression of another cast.
duplicating a cast.The process of producing a duplicate cast.
duplicating material.A substance such as hydrocolloid used to make an impression so an accurate
copy of the cast can be produced.
eccentric.Any position of the mandible other than its normal position.
edentulous.Without teeth; may be an area, arch, or entire mouth.
elastic.Susceptible to being stretched, compressed, or distorted and then tends to resume the original
shape.
elastic limit.The extent to which a material may be deformed and still returned to its original form
after removal of the force.
electric current.The flow of electrons from one point to another.
electrode.Either pole of an electric mechanism.
electrolyte.The liquid used in electroplating.
electroplating.The process of covering the surface of an object with a thin coating of metal by means
of electrolysis.
electropolishing.The removal of a minute layer of metal by electrolysis to produce a bright surface.
elongation.The amount a metal will stretch before breaking.
embrasure.The space defined by surfaces of two adjacent teeth. The space is divided into
occlusal/incisal, facial, lingual, and gingival areas.

emergence profile.The contour of a tooth or restoration, such as a crown on a natural tooth or dental
implant abutment, as it relates to the adjacent tissues.
emery.An abrasive substance used as a coating on paper discs used to smooth and polish.
eminence.A prominence or projection, especially on the surface of a bone.
enamel.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 and forming the
bulk of the enamel.
endodontia.The branch of dentistry dealing with diagnosing and treating nonvital teeth.
envelope of motion.The three-dimensional space made by the mandibular border movements in which
all unstrained mandibular movement occurs.
equilibration of occlusion.See occlusal equilibration.
erosion.The superficial wearing away of tooth substance due to chemical agents. Most often seen on
labial and buccal surfaces.
esthetics.Harmony of form, color, and arrangement. The quality of a pleasing appearance.
etiology.The causative factors which produce a disease.
eugenol.
1. An aromatic oil derived from clove oil to relieve pulpal pain.
2. May also be combined with zinc oxide to make a temporary sedative cement.
3. A principal ingredient in zinc oxide eugenol impression pastes.
excursion.The movement occurring when the mandible moves away from MI.
external or lateral.Surfaces farther from the medial plane.
extracoronal.Outside of the crown portion of a natural tooth.
extraoral.Outside of the mouth.
extrinsic.Outside, as opposed to intrinsic or inside.
extrinsic coloring.Coloring from without; applying color to the external surface of a prosthesis.
extrusion.The movement of teeth beyond the natural occlusal plane; may be accompanied by a similar
movement of their supporting tissues and/or bone.
face form.The outline of the face from an anterior view.
face profile.The outline of the face from the side or lateral view.
facebow.A device used to record the relationship between the maxillae and the temporomandibular
joints and to transfer this relationship to the articulator.
facebow fork.A device used to attach the facebow to an occlusion rim, or to index the maxillary teeth,
for a facebow transfer.
facial.
1. Pertaining to the face.
2. The surface of the tooth or appliance nearest the lips or cheeks. Used synonymously for the
words buccal and labial.
facing.The thin veneer of porcelain or resin that closely fits a metal backing; used in fixed dentures
and RPDs.
facial moulage.A negative reproduction of the face made out of artificial stone, plaster of paris, or
other similar materials.
female attachment.See matrix.
festooning.Shaping and contouring a denture wax-up or the cured denture base to simulate natural
tissue.
fin.A flash of excess metal that results from a fracture in the investment mold.
fineness.The proportion of pure gold in a gold alloy; the parts per 1,000 of gold.

finish line.
1. On an artificial tooth, the raised line in the cervical region used as a guide to trim the wax on the
denture base material.
2. In RPDs, the special preparation placed in the metal to form a definite sharp junction between the
metal and acrylic resin.
finishing.
1. The process of smoothing and trimming a prosthesis before its final polish.
2. The entire procedure of smoothing and polishing.
first molar.The 6-year molar. The 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.
fistula.An abnormal passage resulting from incomplete healing.
fixed bridge.See fixed partial denture.
fixed partial denture.A fixed dental prosthesis, cemented to the prepared teeth or attached to
implants, restoring one or more, but fewer than all of the missing natural teeth.
fixture.
1. Something fixed or attached.
2. The intraosseous portion of a dental implant.
flange.The part of the denture base that extends on the facial or lingual surface from the finish lines of
the teeth to the periphery.
flash.
1. The overflow of denture base material that results from over-packing a denture mold.
2. The thin metal fins that sometimes occur on castings.
flash point.The temperature at which a vapor ignites.
flask.
1. A metal case or tube used in investing procedures. Holds the casts and the investment during the
packing and curing phases of denture construction. The metal ring used to invest a wax pattern.
2. To flask or surround; to invest.
flasking.The process of investing a waxed pattern to create a mold.
flat plane tooth.See nonanatomic teeth.
flexible.Capable of being bent without breaking.
flexure line.See vibrating line.
flow.Deformation of a material under loading.
flow on wax.To melt and apply the wax in liquid form.
flux.
1. A substance used to increase fluidity and prevent or reduce oxidization of a molten metal.
2. Any substance applied to the surfaces to be joined by soldering to clean and free them from
oxides and promote union.
foil.An extremely thin, pliable sheet of metal, usually of variable thickness.
foramen.An opening in a bone or tooth allowing for the entrance or exit of blood vessels and nerves;
for example, the apical foramen in the tooth.
fossa.An anatomical pit, groove, or depression.
fovea palatina.Two small pits or depressions in the posterior aspect of the palate, one on each side of
the midline at or near the attachment of the soft palate to the hard palate.
fox plate.A device occasionally used by dentists to establish the occlusal plane on occlusion rims.
Used to compare with arbitrary lines or planes on the head; for example, Camper¡¯s line.
framework.The metal skeleton of an RPD or metal-ceramic fixed partial denture.

Frankfort horizontal plane.A horizontal plane represented in profile by a line between the lowest
point on the margin of the orbit to the highest point on the margin of the auditory meatus. It nearly
parallels the upper member of an articulator, making it a useful plane of orientation for setting denture
teeth.
freehand waxing.A method of waxing in which wax is flowed from an instrument directly onto the
refractory cast to form the removable partial denture framework.
freeway space.See interocclusal rest space.
frenum.See frenulum. (Plural: frenums or frena.)
frenulum.The small band or fold of connective tissue covered with mucous membrane that attaches
the tongue, lips, and cheeks to adjacent structures.
friable.Capable of being easily crumbled into small pieces; brittle.
frontal bone.The bone that forms the front part of thecranium.
fulcrum.The support on which a lever rests when a force is applied. In RPDs, an abutment tooth may
act as a fulcrum for the appliance.
fulcrum line.An imaginary line through the abutment teeth around which an RPD would rock if not
prevented from doing so.
functional mandibular movements.All natural, proper, and characteristic movements of the
mandible made during speaking, chewing, yawning, swallowing, etc.
furnace.
1. burnout.The gas or electric oven used to eliminate the wax from a mold.
2. porcelain.A specially constructed oven used to fuse dental porcelain.
fusible.Able to be 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 melting range.
gauge.A measure of the thickness or diameter of an object.
galvanic current.A current of electricity produced by chemical action between two metals suspended
in liquid.
garnet.An abrasive, glass-like coating on paper discs used for smoothing and polishing.
gelatin.The solidification of a liquid substance in which a gel forms and acts as a matrix between the
undissolved particles. Alginate gels as it sets.
gingiva.The gum tissue.
gingival crevice.The shallow fissure formed by the attachment of the gingiva to the crown of the
tooth.
gingivectomy.The removal of the gingival tissue from around the necks of the teeth.
gingivitis.An inflammation of the gingiva.
glaze.The final firing of porcelain in which the surface is vitrified and a high gloss is imparted to the
material.
gold.A noble metal used extensively in dentistry, most commonly in the form of an alloy.
gold alloy.An alloy consisting of gold mixed with other metals, such as silver, platinum, copper, and
palladium.
grain.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 process produces a brittle metal.
gram.A unit of weight in the metric system, equal to approximately 15 grains in the apothecaries¡¯
system of weight.
groove.A long narrow depression on the surface of a tooth, such as the indentation between two cusps.

group function.Multiple contact relations between the maxillary and mandibular teeth in lateral
movements on the working side; simultaneous contact of several teeth act as a group to distribute
occlusal forces. Also called unilateral balance.
gypsum.The natural hydrated form of calcium sulfonate.
half flasking.The process of investing the denture in the lower or first half of the denture flask.
hamular notch.See pterygomaxillary notch.
handpiece or straight handpiece.The instrument used to hold and spin burs and mounted points in
dental operations.
hard palate.The anterior two-thirds of the roof of the mouth composed of relatively hard, unyielding
tissue.
hardening heat treatment.See tempering.
heat soaking.The process of allowing the invested inlay or RPD to remain in the oven at the burnout
temperature for a prescribed length of time to remove all carbon and properly expand the mold.
heat treatment.In its broadest sense, the annealing or tempering of an alloy. (Sometimes the term heat
treatment is confined solely to the tempering.)
heel of a denture.The posterior extremities of a denture. The heel corresponds with the retromolar pad
area of the lower denture and the tuberosity area of the upper denture.
height of contour.The greatest circumference of the crown of a tooth.
high lip line.The horizontal line the dentist marks on the occlusion rim to indicate the approximate
level of the upper lip when the patient smiles. Used to help select the length of the anterior teeth.
highly adjustable articulator.An articulator that allows replication of three dimensional movement
of recorded mandibular motion.
hinge axis.See transverse horizontal axis.
hinge joint.A joint that moves in only two directions, such as the knee joint.
horizontal overlap.The projection of teeth beyond their antagonists in a horizontal direction. Also
called overjet.
hue.The basic color. White, black and grays possess no hue.
humidor.A container used to maintain a humid atmosphere.
hydration.The addition of water to a substance. Plaster that has absorbed water from the air is said to
be hydrated.
hydrocal.A form of gypsum that is harder and more durable than ordinary dental plaster.
hydrocolloid.An impression material used extensively in dentistry. It 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.¡±
hygienic pontic.A pontic that is easier to clean because it has a domed or rounded cervical form and
does not have contact with the ridge. Generally used in the posterior where esthetics are of no concern.
hyperplasia.The abnormal overgrowth of a part. Increase in size and number of cells.
hyperplastic tissue.Excessive tissue proliferation, usually as a response to chronic irritation.
immediate denture.A complete denture or RPD fabricated for placement immediately following the
removal of natural teeth.
implant.See dental implant.
impression.A negative reproduction of a given 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 impressions of the mouth. It contains
accelerators and, usually, coloring and flavoring agents. It may also contain starch.

impression tray or stock tray.See stock impression tray.
impression tray, individual.See custom tray.
impression, final.An impression used to form the master cast.
impression, functional.An impression that captures supporting structures in the form they will
assume during mastication.
impression, pickup.An impression in which an object is lifted off the teeth by the impression
material. When the cast is poured, the object will be seated in its proper place on the cast.
impression, two-piece.An impression taken in two separate steps with (usually) two separate types of
impression materials.
incisal.The cutting edge of the anterior teeth.
incisal edge.The biting edge of an anterior tooth.
incisal pin.See anterior guide pin.
incisal rest.A rigid extension of an RPD that contacts a tooth at the incisal edge.
incisal table.See anterior guide table.
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.
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.
incisor.Teeth with cutting edges; the centrals and laterals.
inclination.Deviation of the long axis of a tooth with respect to a vertical line of reference. The four
basic directions of inclination are described as facial, lingual, distal, and mesial.
inclined plane.A surface that slopes at an angle from the horizontal plane.
index.A guide, usually of a rigid material, used to reposition teeth or other parts in some original
position.
indirect inlay technique.A method of waxing the pattern on a die outside of the mouth.
indirect retainers.A part of an RPD framework located on the opposite side of the fulcrum line from
tipping forces and designed to counteract those forces.
induction casting machine.A specially constructed casting machine that melts metal by using an
electric current of extremely high frequency.
induction current.The process of generating an electric current in a conductor using a magnetic field.
inferior.Below.
infrabulge.The area on a tooth below the survey line.
infrabulge clasp.See bar clasp.
ingot.Gold supplied in the form of one or two pennyweight (1.55 or 3.1 grams) pieces. Some of the
base metal alloys are supplied in small cylinders and are 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.
injection molding.The method of denture molding by adapting a plastic material into a closed mold
by forcing or pressing the material through sprue channels.
inlay.A restoration made to fit inside a prepared tooth cavity and cemented into place.
insertion.
1. The attachment point for a muscle in the bone or other structure to be moved.
2. See placement.
intaglio surface.The portion of the denture or other restoration having its contour determined by the
impression; the internal or reversal surface of an object. Also called internal surface or tissue surface.

interarch distance.The interridge distance; the vertical distance between the maxillary and
mandibular edentulous arches under specified conditions. Also called intermaxillary space.
intercondylar distance.The distance between the rotational centers of two condyles.
interdigitation.See maximum intercuspation (MI).
interim prosthesis.A fixed or removable prosthesis, designed to enhance esthetics, stabilization,
and/or function for a limited period of time, after which it is replaced by a permanent prosthesis.
interlock.A device connecting a fixed unit or a removable prosthesis to another fixed unit.
interlock fixed partial denture.A fixed partial denture constructed in two pieces containing a matrix
and patrix. Also called broken stress fixed partial denture.
intermaxillary space.See interarch distance.
intermediate abutment.A natural tooth located between terminal abutments serving to support a
fixed or removable prosthesis.
internal or medial.Surfaces closer to the medial plane.
interocclusal rest space.The difference between the vertical dimension at rest and the vertical
dimension in occlusion. Also called freeway space.
interproximal.Between adjoining tooth surfaces.
interproximal space.The space between two adjacent teeth.
intraoral.Within the mouth.
intraoral tracing.A tracing made within the mouth.
intrinsic coloring.Coloring from within; the incorporation of a colorant within the material of a
prosthesis or restoration.
inverted spruing.A method of spruing a cast RPD in which a hole is made in the investment model so
the sprue approaches the wax pattern from underneath.
invest.To envelop or embed an object in an investment material.
investment.
1. The gypsum material used to enclose a denture wax pattern in the flask, forming a mold.
2. In fixed or removable prosthetics, a heat resistant material used to enclose a wax pattern before
wax elimination.
investment cast.See refractory cast.
jacket crown.See ceramic crown or resin crown.
jaw.A common name for the maxillae or mandible.
jaw relation.See maxillomandibular relationship.
Kennedy classification.A system of classifying partially edentulous arches based on the pattern of
tooth loss.
key.
1. 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.
2. To prepare a surface with a cut or groove.
Knoop hardness.A surface hardness test using a diamond stylus.
labial.Pertaining to the lips. The surface of an anterior tooth opposite the lips.
labial bar.The metal piece or major connector connecting the right and left sides of a lower RPD.
Contoured to the labial tissue anterior to the lower teeth.
labial frenum.The connective tissue attaching the upper or lower lip to the alveolar ridge at or near
the midline.
labial notch.The V-shaped indentation in an impression or denture, formed by or for the labial
frenum.
lamina dura.The layer of compact bone forming the wall of a tooth socket.

land area.The portion of a dental cast extending beyond the impression¡¯s replica surface, laterally
defining the area between the end of the replica¡¯s surface and the cast.
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.
laterotrusion.Condylar movement on the working side in the horizontal plane. This term may be used
in combination with terms describing condylar movements in other planes; for example, laterodetrusion,
lateroprotrusion, lateroretrusion, and laterosurtrusion.
ledging.The process or 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.
lesion.Any hurt, wound, or local degeneration.
leverage.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.
lingual.Pertaining to the tongue. The surface of a tooth or prosthesis next to the tongue is the lingual
surface.
lingual bar.The metal piece of a major connector used to connect the right and left sides of a lower
RPD. It is contoured to the lingual tissue behind and below the anterior teeth.
lingual flange.The part of a denture or impression extending from about the crest of the ridge to the
periphery on the lingual surface.
lingual frenum.The band of tissue attaching the tongue to the floor of the mouth.
lingual notch.
1. The indentation on the lingual periphery of a lower impression made by the lingual frenum.
2. An indentation provided in the same area of the denture to allow free movement of the lingual
frenum.
lingual plate.The solid plate of metal that is continuous with the lingual bar and rests against the
lingual surfaces of the anterior teeth. It functions as a connector and sometimes as a periodontal splint
for loose teeth.
lingual rest.A rest on an RPD placed on the lingual surface of an anterior tooth. Sometimes used on
the free end of a cantilever fixed partial denture.
lingualized articulation.A denture occlusion using anatomic maxillary teeth against nonanatomic
mandibular teeth. Also called lingualized occlusion.
long axis.An imaginary line passing lengthwise through the center of a tooth.
low fusing alloy.Any one of the alloys that melt at very low temperatures.
major connector.A part of an RPD framework connecting one side of the appliance with the other. A
lingual bar is an example.
male attachment.See patrix.
malleability.The property of a metal that permits it to be extended in all directions without breaking.
malocclusion.Defective occlusion or deviation from normal occlusion.
malposition.Incorrect positioning of teeth.
mamelons.Small elevations of enamel present on incisors as they erupt; quickly worn down during
mastication.
mandible.The lower jaw.

mandibular.To refer to the mandible or lower jaw.
mandibular translation.The translatory (medio-lateral) movement of the mandible when viewed in
the frontal plane.
mandrel.The spindle or shank that fits into the lathe chuck or handpiece and holds a stone or disc.
margin.
1. A border or boundary, as between a tooth and a restoration.
2. The outer edge of a crown, inlay, or onlay.
marginal ridge.The elevations of enamel forming the mesial and distal boundaries of the occlusal
surfaces of the posterior teeth and the mesial and distal boundaries of the lingual surfaces of the anterior
teeth.
masking.The process of applying an opaque covering to camouflage the metal component of a
prosthesis. Also called opaqueing.
masseter muscle.A muscle of mastication that 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 impression.
master impression.The negative impression from which the master cast is made.
mastication.The chewing of food.
masticatory cycle.A three-dimensional representation of mandibular movement produced during the
chewing of food. Also called chewing cycle.
matrix.
1. The mold in which something is formed to use as a relationship record. See index.
2. The portion of a dental attachment system that receives the patrix. Also called female attachment.
maxilla.The upper jaw.
maxillary.To refer to the maxilla or upper jaw.
maxillary orthopedic appliance (bite guard).See maxillary orthotic appliance.
maxillary orthotic appliance.An acrylic resin appliance designed to cover the occlusal and incisal
surfaces of the maxillary teeth of a dental arch to stabilize the teeth and/or provide a flat platform for
unobstructed excursion glides of the mandible.
maxillary tuberosity.An area in the form of a bulge at the posterior end of the maxillary alveolar
ridge.
maxillofacial prosthetics.A subspecialty of prosthodontics where prostheses are fabricated to replace
missing or damaged head and neck structures; for example, artificial eyes, ears, noses, or obturator
dentures.
maxillomandibular relationship.Any spatial relationship of the maxilla to the mandible. Also called
jaw relation.
maxillomandibular relationship record or registration.A record of the relationship of the mandible
to the maxillae.
maximum intercuspation (MI).The complete intercuspation of the opposing teeth independent of
condylar position.
medial raphe.The fibrous tissue extending along the middle of the hard palate.
median line.
1. An imaginary line extending through the middle of the face.
2. The midline of a cast.
median (medial).Toward the middle.
median plane.The plane dividing the body in equal left and right halves.
melting point.The point at which a pure metal becomes molten, or changes from a solid to a liquid.

melting range of an alloy.The interval between the temperature at which the alloy begins to melt
(solidus) and the temperature at which it is completely molten (liquidus).
mental foramen.A foramen on the facial surface of the mandible near the roots of the bicuspids,
through which the mental vessels and nerves pass.
mesial.The surface of a tooth nearest the midline in a normal occlusion.
metal.A substance that, to some degree, is malleable and ductile and conducts heat and electricity.
metal base denture.See cast base.
metal ceramic restoration.A fixed restoration consisting of a metal alloy substructure covered with a
veneer of porcelain. Also known as porcelain fused to metal and ceramo-metal restoration.
metamerism.The phenomenon occuring when the color of two objects match in one lighting
condition, but do not match in others.
methyl-methacrylate.The chemical name for synthetic acrylic resin. One of its most common uses is
as denture base material for complete dentures and RPDs.
metric system.A decimal system of weights and measures. The basic units are the meter for length
and grams for weight or mass.
midline.The imaginary line through the middle of an object, dividing the object into equal parts.
milliampere.One-thousandth (1/1000) of an ampere.
millimeter.A unit of length in the metric system equal to 1,000 microns or one-thousandth of a meter.
mill in.
1. The procedure of refining occluding surfaces through the use of abrasive materials.
2. The machining of boxes or other forms in cast restorations to be used as retainers for fixed or
removable prostheses.
minor connector.The part of an RPD uniting clasps and rests to the remainder of the framework.
modeling plastic impression compound.A thermoplastic dental impression material.
modulus of elasticity.A complex measure of the elasticity of a material determined by its ratio of
stress to strain. As the modulus of elasticity rises, the material becomes more rigid.
molars.The teeth situated in the posterior region of the mouth. The teeth behind the premolars.
mold.
1. The hollow form or matrix in which an object is cast or shaped.
2. The shape of an artificial tooth.
monomer.A chemical compound that can undergo polymerization. The most common is methyl
methacrylate liquid.
morphology, tooth.The study of the form and structure of a tooth.
mounting.
1. The laboratory procedure of attaching a cast to an articulator.
2. The relationship of dental casts to each other and the instrument to which they are attached.
mounting plate.The removable metal, resin, or plastic piece that attaches the dental casts to the upper
and lower members of the articulator.
mucolabial fold.The junction between the cheek and the alveolar mucosa of the upper or lower jaw.
mucous membrane.The soft tissue outlining the mouth.
mutually protected articulation.An occlusal scheme in which the posterior teeth prevent excessive
contact of the anterior teeth in MI and the anterior teeth disengage the posterior teeth in all mandibular
excursive movements.
mutually protected occlusion.See mutually protected articulation.
mylohyoid ridge.An oblique ridge on the lingual surface of the mandible that extends from the level
of the roots of the last molar teeth and serves as a bony attachment for the mylohyoid muscles forming
the floor of the mouth.

nasal bone.The two small bones forming the arch of the nose.
nasolabial fold.The crease between the nose and the upper lip.
noble metal.A metal not readily oxidized at ordinary temperatures or by heating; for example, gold or
platinum.
non-noble.A metal that is expected to form oxides or sulfides; for example, silver or tin.
nonanatomic teeth.Artificial teeth that do not conform to the anatomy of natural teeth. Also called
flat-plane or zero-degree teeth.
nonprecious.Metals or alloys that are not scarce and do not possess a high intrinsic value. Examples
are nickel and chromium. The term ¡°nonprecious¡± is regarded by many as less technically correct than
the preferred term ¡°base metal.¡±
nonworking side.The side of the mandible that moves toward the median line in a lateral excursion.
The side opposite the side toward which the mandible moves. Also called balancing side.
nonworking side occlusal contacts.Contacts of the teeth on the side opposite the side toward which
the mandible moves in articulation. Also called balancing side occlusal contacts.
oblique ridge.The transverse ridge of enamel crossing the occlusal surface of the upper molars from
mesiolingual to distofacial.
obturator.A prosthesis used to close an abnormal opening between the oral and nasal cavities.
occipital bone.The bone forming the posterior portion and base of the skull.
occlude.To bring together; to bring the upper and lower teeth together.
occlusal equilibration.
1. To equalize.
2 To remove high spots and areas of interference. To adjust the contact areas between the upper and
lower teeth so each tooth carries an equal share of the occlusal load.
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 RPD that contacts the occlusal surface of the tooth.
occlusal surface.The biting, grinding, or chewing surfaces of molars and bicuspids.
occlusal vertical dimension.The distance measured between two points when the occluding members
are in contact. Also called vertical dimension of occlusion.
occlusion.
1. The act or process of closure or of being closed or shut off.
2. The static relationship between the incising or masticating surfaces of the maxillary or
mandibular teeth.
occlusion rim.See record rim.
opaqueing.See masking.
open bite.Slang for open occlusal relationship.
open occlusal relationship.The lack of tooth contact in an occluding position. Also called open bite.
orbitale.The lowest point in the margin of the orbit (directly below the pupil when the eye is open and
the patient is looking straight ahead) that may readily be felt under the skin. Can be used as a reference
point for making a facebow record.
orientation of occlusal plane.The position the occlusal plane is to occupy between the upper and
lower ridges.
origin.The fixed point of attachment of a muscle.
oven, burnout.See furnace.
overdenture.A prosthesis that covers and is partially supported by natural teeth, tooth roots, and/or
dental implants.
overjet.See horizontal overlap.

overjet principle.The spruing method used to reduce casting turbulence in an RPD mold. In this
system, the sprue leads exit the main sprue below its tip.
ovoid arch form.A dental arch that is oval or round in outline.
oxidation.The process of heating a metal substructure in a porcelain furnace to cleanse the porcelainbearing
surfaces of contaminants and produce an oxide layer for porcelain bonding. Also called
degassing.
oxidize.To combine with oxygen; for example, iron rust or brass tarnish.
oxypropane torch.A blowtorch mixing propane gas and pure oxygen to produce a much hotter flame
than either natural gas and air or propane and air.
packing a denture.To place the acrylic dough in the mold and close the flask.
palatal bar connector.A major connector of an RPD that crosses the palate and is characterized by
being relatively narrow anteroposteriorly.
palate.The roof of the mouth; classified into both hard and soft palate areas.
palatine bone.The paired bones forming the posterior one-third of the hard palate.
pantograph.An instrument used to graphically record in one or more planes paths of mandibular
movement and provide information for the adjustment of an articulator.
papillary hyperplasia.Abnormal tissue growth found on the hard palate.
paraffin.A white, waxy hydrocarbon distilled from coal or petroleum and used to compound several
dental waxes.
parafunctional mandibular movement.Disordered movement of the mandible; for example,
movements associated with tension, emotion, or aggression.
parietal bone.The two quadrilateral bones forming the sides of the skull.
partial veneer crown.A restoration restoring all but one coronal surface of a tooth, usually not
covering the facial surface.
Passavant¡¯s cushion or pad.A small bulge of soft tissue on the posterior and lateral walls of the
nasopharynx at the level of the hard palate. Aids in closing the opening between the nasal and oral
cavities when swallowing.
Passavant¡¯s ridge.See Passavant¡¯s cushion or pad.
passive.
1. Not active or in operation.
2. Resistant to corrosion.
3. Existing or occurring without being active, direct, or open.
passivity.The quality or condition of inactivity or rest assumed by the teeth, tissues, and denture when
an RPD is in place, but not under masticatory pressure.
pathogen.Any disease producing agent; for example, a virus, bacterium, or microorganism.
pathogenic.Capable of producing disease.
path of insertion.See path of placement.
path of placement.The specific direction in which a prosthesis is placed on the abutment teeth.
patrix.The extension of a dental attachment system that fits into a matrix. Also called male
attachment.
pennyweight.See Troy weight.
periapical.The area around the apex or root tip of a tooth.
periodontics.The branch of dentistry dealing with the science and treatment of the tissues and bone
surrounding the teeth.
periodontium.Collectively, the tissues surrounding and supporting the tooth.
periosteum.The tough fibrous membrane covering the outer surface of all bone except at articular
surfaces.

peripheral roll.See denture border.
petrolatum.A lubricant used as a separator in many dental laboratory procedures.
phonation.Action constituting a source of vocal sound.
phonetics.
1. The science or study of speech sounds and their production, transmission, and reception.
2. The symbols representing the speech sounds of a language. A denture patient¡¯s ability to say ¡°s¡±
and ¡°ch¡± clearly with the appliance in place.
physiology.The branch of biology dealing with the functions and activities of living organisms and
their parts, including all physical and chemical processes.
physiologic rest position.The position of the mandible where all the masticatory muscles are in a
relaxed state.
pier abutment.See intermediate abutment.
pigment.A finely ground powder used to impart color to a material.
placement.The process of directing a prosthesis to a desired location; the introduction of prosthesis
into the patient¡¯s mouth. Also called insertion.
plaster of paris.A white, powdery, slightly hydrated calcium sulfate used to make casts and molds
when combined with water to form a quick setting paste.
plastic.
1. Capable of being shaped or formed.
2. Pertaining to the alteration of living tissues.
3. Any of numerous organic synthetic or processed materials that are generally thermoplastic or
thermosetting polymers. They can be cast, extruded, molded, drawn, or laminated into films,
filaments, and objects.
pit.A depression usually found where several developmental lines intersect.
point angle.The angle made on a tooth by the convergence of three planes or surfaces.
polishing agent.Any material used to impart a luster to a surface.
polymer.Compound (powder) composed of smaller organic units. Most common in dentistry is methyl
methacrylate powder.
polymerization.The reaction that takes place between the powder and liquid during the curing of
acrylic resin. Characterized by joining together molecules of small molecular weights to a compound of
large molecular weight.
pontic.The part or parts of a fixed partial denture replacing a missing tooth or teeth, usually restoring
function and space occupied by the natural crown.
porcelain.A ceramic material. In dentistry, most porcelains are glasses and are used in the fabrication
of teeth for dentures, pontics, facings, metal ceramic restorations, and other restorations.
porcelain fused to metal restoration.See metal ceramic restoration.
porous.Pitted; not dense. Containing voids and bubbles.
porosity.The presence of voids or pores within a structure.
post.
1. A retention mechanism for acrylic resin teeth used on an RPD.
2. The portion of a dowel (post and core) restoration that extends into the root portion of a tooth.
posterior.Situated in back of or behind.
posterior palatal seal.See postpalatal seal
postpalatal seal.An elevation of acrylic resin on the tissue side of the posterior border of a maxillary
appliance for the purpose of sealing it against the resilient soft tissue in the palate.
posterior tilt.When a cast is surveyed with the posterior part of the cast lower than the anterior.
posterior teeth.Premolars and molars.

precious metal.A metal containing primarily elements of the platinum group, gold, and silver.
precious metal alloy.An alloy predominantly composed of elements considered precious.
precision attachment.A retainer consisting of a metal receptacle (matrix) and a closely fitting part
(patrix). The matrix is usually contained within the normal or expanded contours of the crown on the
abutment tooth; the patrix is attached to a pontic or RPD framework.
preliminary cast.A cast formed from the preliminary impression used for the purpose of diagnosis,
treatment planning, or the fabrication of a custom tray.
preliminary impression.A negative reproduction made to form a preliminary cast.
process.
1. A prominence or projection of bone.
2. In dentistry, any technical procedure that incorporates a number of steps; for example, the
procedure of polymerization of dental resins for prostheses or bases.
prognosis.A forecast of the probable outcome of an illness.
propane.A flammable gas found in petroleum and natural gas.
prophylaxis.The removal of calculus and stains from the teeth.
proportional limit.The amount of stress a metal will stand before it is permanently stretched or bent;
a measure of the strength and toughness of an alloy.
prosthesis.An artificial replacement for a lost part of the body. In dentistry, it is used in the more
limited sense of a strictly dental replacement. (Plural: prostheses.)
prosthodontics.The branch of dentistry pertaining to the restoration and maintenance of oral function,
comfort, appearance, and health of the patient by the restoration of natural teeth and/or the replacement
of missing teeth and contiguous oral and maxillofacial tissues with artificial substitutes.
protrude.To project forward.
protrusion.
1. The act of protruding something forward.
2. In dentistry, a position of the mandible anterior to centric relation.
protrusive interocclusal record.A registration of the mandible in relation to the maxillae when both
condyles are advanced in the temporal fossa.
protrusive articulation.Occlusal contact relationships between maxillary and mandibular teeth when
the mandible moves into a forward position.
protruberance.A projecting part; bulge.
proximal.
1. Situated close to.
2. Next to or nearest the point of attachment or origin.a central point.
proximal tooth surface.The surface of a tooth that lies next to another tooth.
pterygomaxillary notch.The notch formed by the junction of pterygoid hamulus of the sphenoid bone
and maxilla. Located just posterior to the maxillary tuberosity. Also called hamular notch.
pulp.The connective tissue found in the pulp chamber and canals and made up of arteries, veins,
nerves, and lymph tissue.
pumice.A type of volcanic glass used as an abrasive agent in many polishing procedures.
quadrant.One of the four sections of the dental arches, divided at the midline.
quench.To cool suddenly by plunging into a liquid.
quick cure resin.See autopolymerizing resin.
ramus.The ascending part of the mandible.
rational posterior teeth.See nonanatomic teeth.
rebase.Complete replacement of the denture base, saving only the denture teeth.

reciprocal arm.The rigid arm of the clasp located on the tooth, opposing any pressure exerted by the
retentive arm. Acts to stabilize the appliance and resist lateral displacement. Also called bracing arm or
reciprocal clasp.
reciprocity.The state of being inversely related or proportioned; opposite.
record base.An interim denture base used to support the record rim material for recording
maxillomandibular records.
record rim.The occlusal surfaces fabricated on a record base for the purpose of making
maxillomandibular relationship records and/or arranging teeth. Also called occlusion rim.
reducing zone of a flame.The zone of a flame least apt to cause oxidation of the metal when melting
or soldering.
reducing investment.A specially made investment that contains fine graphite or copper particles to
prevent oxidization of the casting. Also called deoxidizing investment.
refractory cast.A cast made of a heat resisting material. Also called investment cast.
reinforced acrylic pontic (RAP).An anterior acrylic resin denture tooth attached to a specially
constructed retentive site on an RPD framework.
relief.
1. The reduction or elimination of undesirable pressure or force from a specific region; for example,
the scraping of a working cast to better fit a facing to the ridge.
2. Material added to a cast to relieve the pressure over specific areas in the mouth. Also added to
the master cast before duplicating it to create a raised area on the refractory cast.
reline.The replacement of the tissue surface of the denture to make it fit more accurately.
removable partial denture (RPD).A dental prosthesis that artificially replaces teeth and associated
structures in a partially edentulous dental arch and can be removed and replaced by the patient.
reservoir.
1. An area where extra supply or stock is collected or accumulated.
2. In dentistry, an attachment to the sprue to provide additional molten metal when the casting
begins to solidify and shrink.
resin.
1. A gummy substance obtained from various trees used to make many dental materials.
2. A broad term used to describe natural or synthetic materials that form plastic materials after
poly-merization.
resin, denture.See acrylic resin.
resin crown.A resin restoration restoring a clinical crown without a metal substructure.
resorption.The loss of tissue substance by physiologic or pathologic processes. The roots of the
primary teeth are resorbed naturally.
rest.A supporting device of an RPD lying on the occlusal or incisal surface of a tooth..
rest position.See physiologic rest position.
rest seat preparation.The preparation made on a tooth to accommodate an occlusal or incisal rest.
retainer.Any type of device used for the stabilization or retention of a prosthesis. In RPDs, a clasp is
called a direct retainer. In fixed partial dentures, an abutment casting is called a retainer.
retention of a clasp.The property that enables a clasp to resist dislodgement.
retromolar pad.The soft tissue pad at the posterior extremity of the mandibular ridge.
retrusion of the mandible.A backward movement of the mandible.
reverse curve.A curve of occlusion defined by the cusp tips and incisal edges which, when viewed in
the sagittal plane, is curved upward or superiorly.

reverse articulation.An occlusal relationship in which the mandibular teeth are located facial to the
opposing maxillary teeth. The maxillary buccal cusps are positioned in the central fossa of the
mandibular teeth. Also called crossbite.
reversible hydrocolloid.An impression material containing agar that 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.¡±
rhomboidal.The shape of an oblique-angled parallelogram with only the opposite sides equal. The
occlusal outline of the maxillary molars are rhomboidal.
ridge.
1. An elevated body part; a long, narrow, raised crest.
2. A linear elevation of enamel on the surface of a tooth; for example, a marginal ridge.
3. (Alveolar ridge) The area of the upper and lower jaws formerly occupied by the natural teeth.
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 that normally overlaps the alveolar ridge. On the inner surface
of the denture tooth, it corresponds approximately to the location of the collar on the facial surface.
ridge relationship.The position of the upper and lower ridges relative to each other.
ridge resorption.The resorption of the alveolar bone once teeth are no longer present, resulting in a
progressively flatter ridge.
ring.A metal cylinder used to confine the investment when investing the pattern for a fixed wax
pattern or an RPD framework pattern.
Roach clasp.See bar clasp.
Rockwell hardness.A measurement of the hardness of metals that are too hard for the Brinell needle.
root.The portion of the tooth covered with cementum.
root canal.The small channel running through the tooth¡¯s root, connecting the pulp chamber and the
root-end opening.
rouge, jeweler¡¯s.A red powder usually in cake form used on a buff or chamois wheel to impart a high
luster to metal.
rubber points/wheels.Rubber impregnated with abrasive used for smoothing ground surfaces.
rugae.The elevated folds or wrinkles of soft tissue situated in the anterior part of the palate.
safeside disk.An abrasive disk having one smooth side so it does not damage or scratch adjacent
surfaces or structures.
sagittal plane (mid).The plane dividing the body vertically into two equal halves.
sandpaper disks.Various size disks with different grits of sandpaper on their surface used for
smoothing and polishing in the laboratory.
sanitary pontic.See hygienic pontic.
sanitization.A process that removes gross debris and reduces the number of microorganisms on
nonliving material.
saturated calcium sulphate dihydrate solution (SDS).A clear, true solution of water and a
maximum amount of dissolved, dihydrate (set) gypsum product.
second half-flasking.Completion of the investing process in the top half of the denture flask.
semirigid fixed partial denture.See interlock fixed partial denture.
separating medium.An agent used between two surfaces to prevent them from sticking together.
serrated.Indented with many shallow crosscuts.
setting expansion.The dimensional increase that occurs concurrent with the hardening of various
materials, such as plaster of paris, dental stone, die stone, and dental casting investment.
setting time.The time necessary to harden or solidify.
setup.See tooth arrangement.

shade.A particular hue or variation of a primary hue, such as a greenish shade of yellow.
shelf life.The period of time a material can be stored without losing its useful properties.
shellac base.A record base constructed using a shellac-based wafer that has been adapted to the cast
with heat.
sideshift.Articulator simulation of mandibular translation.
slurry.A fluid mixture of a liquid and undissolved solid. Used to accelerate the setting time of dental
stone.
soft palate.The movable part of the palatal anatomy posterior to the hard palate.
solder.
1. A fusible metal alloy used to unite the edges or surfaces of two pieces of metal.
2. The act of uniting two pieces of metal by the proper alloy of metals.
soluble.Capable of being dissolved.
solute.In a solution, the dissolved solution is called the solute. In salt water, the water is the solvent
and the salt is the solute. See solvent.
solvent.A substance capable of dissolving another substance; for example, water is the solvent of salt.
See solute.
spatula.
1. An instrument designed for mixing; a flat, knife-like instrument used for mixing plaster,
hydrocal, and investment.
2. An instrument that 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 formula is 1 cm3 of water at 4 oC = 1.
sphenoid bone.The irregular, wedge-shaped bone at the base of the skull.
spindle, surveyor.The perpendicular part of the surveyor containing a chuck that holds the
interchangeable tools.
splint.
1. A rigid or flexible device that keeps a displaced or movable part in position.
2. A rigid or flexible material used to protect, immobilize, or restrict motion in a part.
split remounting plate.A device consisting of two machined metal plates. One part is embedded in
the cast, and the other is embedded into the articulator mounting. The cast can then be removed from the
mounting and accurately replaced.
sprue.
1. The channel or hole through which plastic or metal is poured or cast into a reservoir and then into
a mold.
2. The cast metal or plastic that connects a casting to the residual sprue button.
sprue base.See crucible former.
sprue button.The material remaining in the reservoir of the mold after casting.
sprue former .A wax, plastic, or metal pattern used to form the channel or channels to allow molten
metal to flow into a mold to make a casting.
square arch form.A dental arch roughly square in outline, particularly in the anterior region.
stability.The property of resistance to tipping and rocking of a prosthesis.
stabilized record base.A record base lined with an impression material to increase its stability.
stent.An appliance, usually of acrylic resin, used to reposition soft tissue.
sterilization.The process by which all forms of life within an environment, including viruses and
spores, are totally destroyed.
stock impression tray.A device with a handle used to confine and hold an impression material as it is
carried to place in the mouth to make an impression.

stone.See dental stone.
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. Same as stone cap.
strain.The deformation of a material caused by an external force.
stress.The forces within a substance opposing an external force.
stress breaker.See interlock fixed partial denture.
strut.A name often given to a minor connector.
sublingual.The area under the tongue.
sulcus.
1. A furrow, fissure, or groove.
2. In dentistry, a linear depression in the surface of a tooth, the surfaces of which meet at an angle.
A sulcus is always found along the surface of a developmental line.
sulfuric acid.An acid made up of hydrogen, sulfur, and oxygen. Mixed with water in equal parts, it is
used as a deoxidizing solution for gold.
superior.Above.
supernumerary tooth.An extra tooth; one in excess of the normal number.
support.
1. To hold up or serve as a foundation or prop for.
2. The foundation area on which a dental prosthesis rests.
suprabulge.The area above the survey line on an abutment tooth.
suprabulge clasps.See circumferential clasp.
supraerupted tooth.A tooth that has emerged past the occlusal plane.
surgical guide.Any prosthesis prepared for insertion during a surgical procedure and intended for
short use. Also called surgical template and surgical prosthesis.
surveying.
1. To analyze the master cast for favorable and unfavorable undercut conditions.
2. To establish the path of insertion, using a dental surveying instrument.
surveyor.An instrument used to locate and mark the greatest circumference of one or several
abutment teeth at a given tilt of the cast. Used to locate soft tissue undercuts at a given tilt.
suture line.A junction line where the bones of the cranium unite.
swage.To shape a piece of metal between a die and counterdie.
symphysis, mandibular.The immovable dense midline junction of the right and left halves of the
adult mandible.
T-clasp.A vertical, projection-type clasp formed approximately in the shape of a ¡°T.¡±
tang.The connector between the clasp body and the frame of the appliance.
tapered arch form.A dental arch which, in outline, is between an oval and a square arch.
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 taper ensures the rigid part of the
metal framework does not enter an undercut adjacent to an edentulous space.
tempering.The procedure of imparting a desired degree of hardness to a metal. Also called heat
hardening treatment.
template.
1. A pattern, mold, or gauge used as a guide to form a piece being made.
2. A flattened 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 skull.

temporomandibular joint.The joint formed by the condyle of the mandible, temporal bone, and
associated soft tissues.
tendons.The heavy fibrous bundles attaching a muscle to bone.
tensile strength.A measure of resistance to breakage from a stretching or pulling force.
thermal expansion.The increase in the size of a material when it is heated.
thermoplastic.A material that softens under heat and solidifies when it is cooled without chemical
change.
thirty-degree (30o) teeth.An anatomical type of artificial posterior teeth. The manufacturer claims the
cusp incline forms a 30-degree angle with a horizontal plane.
three-quarter veneer.See partial veneer crown.
Ticonium Premium 100.An alloy characterized by a lower melting range than any of the other
chrome dental alloys.nickel, chromium, and beryllium.
tilt.The position of the cast on the surveyor table relative to a horizontal plane.
tooth arrangement.The placement of teeth on a denture with definite objectives in mind.
tissue-borne.A partial denture where all the masticatory stresses are borne by the soft tissues of the
mouth.
tooth-borne.A partial denture where all the masticatory forces are carried by the abutment teeth.
tooth-supported base.A denture base restoring an edentulous region with abutment teeth at each end
for support. The tissue it covers is not used as support.
torque.A twisting force.
torus.
1. A smooth, rounded, anatomical proturberance.
2. Torus mandibularis.found on the lingual surface of the body of the mandible. There may be
several tori (plural), usually in the area of the midline backward to about the bicuspids.
3. Torus palatinus.found midline on the hard palate.
translatory (sliding) motion.The motion of a rigid body in which a straight line passing through any
two points always remains parallel to its initial position. The motion may be described as a sliding or
gliding motion.
transverse horizontal axis.An imaginary line around which the mandible may rotate within the
sagittal plane. Also called hinge axis.
transverse plane.The plane that divides the top horizontally from the bottom.
transverse ridge.The ridge of enamel formed at the junction of the buccal and lingual ridges on the
occlusal surface of a molar or bicuspid.
trapezoid.A four-sided plane figure with two parallel sides. The occlusal surface of the lower first
molar is trapezoidal in outline.
trauma.A wound or injury, whether physical or psychic.
treatment partial.See interim prosthesis.
treatment plan.An outline of the various clinical steps in the proper sequence to be followed for
restoring a mouth to health and function.
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.
trial record base.See record base.
triangular ridge.The ridge of enamel that extends from the tip of the cusp down onto the occlusal
surface of the bicuspids and molars.
trial placement.The process of checking the trial denture in the patient¡¯s mouth for accuracy and the
suitability and arrangement of the teeth. Also called try-in.
trifurcated.Having three roots.

troy weight.A system of weights used for weighing gold. The basic unit is the grain; 24 grains are
equal to 1 pennyweight.
tube tooth.An artificial tooth containing a vertical channel that fits over a metal post and secures the
tooth to the appliance.
tubercule.A nodule or small eminence.
tuberosity.See maxillary tuberosity.
twenty-degree (20o) teeth.A trade name denoting an artificial posterior teeth with 20-degree cusp
angles.
undercut.The portion of the surface of an object that is below the height of contour in relationship to
the path of placement.
undercut gauge.A tool for the surveyor that is shaped to measure the amount of undercut on a tooth in
thousandths of an inch.
undesirable undercut.Any area that cannot be used for retention and may interfere with insertion and
removal of the prosthesis.
unilateral balanced occlusion.See group function.
vacuum fired.To bake porcelain in a vacuum.
vacuum mixing.A method of mixing a material in asubatmospheric pressure.
value.The dimension of a color denoting relative blackness or whiteness.
vault.The palate or roof of the mouth.
veneer.A thin layer.
vertical dimension of occlusion.See occlusal vertical dimension.
vertical overlap.
1. The distance teeth lap over their antagonists as measured vertically. May also be used to describe
the vertical relations of opposing cusps.
2. The vertical relationship of the incisal edges of the maxillary incisors to the mandibular incisors
when the teeth are in maximum intercuspation.
vestibule.The part of the mouth between the cheeks or lips and the alveolar ridge.
vibrating line.An imaginary line in the soft palate marking the junction between the movable and
immovable tissues. Also called flexure line.
vibrator.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.
viscosity.A measure of a liquid¡¯s resistance to flow or its relative fluidity.
vitrification.The process of making a homogenous, glassy substance by heat and fusion.
volatile.To quickly evaporate.
volatility.The ability to become gaseous or vaporize into gas.
volt.The unit of electrical pressure that forces the current through the circuit.
vomer.The bone forming the lower and posterior portions of the septum of the nose.
warpage.The loss of an original shape or contour.
watt.A unit of electrical power obtained by multiplying the voltage by the amperage.
wax.There are many different types of waxes are used in dentistry, and each is compounded to
produce certain physical properties for a specific purpose. Wax is manufactured in various forms, such
as baseplate, boxing, inlay, and sticky.
wax elimination.The use of heat to remove a wax pattern from the mold.
wax pattern.Wax that has been formed into the size and shape desired in the finished prosthesis and
used to form the mold in the investment.
wax-up (noun).The finished wax pattern for any dental prosthesis.

wax up (verb).
1. To smooth and finish the wax on a complete denture.
2. To flow and carve a wax pattern for a fixed restoration.
3. To contour the wax for any dental prosthesis.
weld.A process for joining metals, using heat and pressure or pressure alone.
working cast.The cast of an entire dental arch or section of an arch on which the laboratory work is
accomplished.
working articulation.Occlusal contacts of teeth on the side toward which the mandible has moved.
Also called working occlusion.
working side.The side toward which the mandible moves in a lateral excursion.
xerostomia.Dryness of the mouth caused from the lack of a normal amount of saliva.
yield strength.The amount of stress required to produce a particular offset that is chosen. A value of
0.2 percent plastic strain is often used (called 2 percent offset).
zero-degree (0o) teeth.See nonanatomic teeth.
zinc oxide.A powder incorporated with eugenol or a similar oil to form a mild antiseptic and analgesic
paste; a constituent of most impression pastes.
zygomatic processes, temporal and maxillary.The bony extensions of the temporal and maxillary
bones that unite with the zygomatic bone to form the zygomatic arch.