Dental Materials Flashcards by Carmina Tan

Inelastic impression

Plaster of paris aka impression plaster or type I stone

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Elastic impressions (4)

Colloidal solutions
ZOE
Impression compounds
Elastomers

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Reversible hydrocolloids are ____ from seaweeds

And is used with specialized equipments**

Agar-agar

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Reversible hydrocolloids impt properties (3)

Imbibition
Syneresis
Hysteresis

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Absorbs water

Imbibition - expansion

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Releases water

Syneresis - syrink

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Ability of material to change its form based on temperature

Hysteresis

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Liquefaction temp

Gel to sol

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Gelation temp

Sol to gel

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Reversible hydrocolloid composition (2)

Water

Agar

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Principal content of reversible hydrocolloid

Water 85%

Agar is 15% only mixed with BORAX (hardener)

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Component of irreversible hydrocolloids (4)

Sodium alginate or K alginate
Ca sulfate
Diatomaceous earth
NaPO4

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Major reactor of irreversible hydrocol

Sodium alginate or K alginate

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Principal component of irreversible hydrocol

Diatomaceous Earth

Made from SILICA *

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Flexites are made from

Nylon

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ZOE contains

Oil of cloves

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Contraindic for zoe (2)

Resins

Cavity varnish

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Most common technique to soften impression compound

Dry heat

Water bath another one :)

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First invented elastomer with the longest setting time

Polysulfide

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Base and catalyst of polysulfide

Base - mercaptan

Catalyst - lead peroxide (causes foul and stains)

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Least dimensionally stable among elastomers

Condensation silicones

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Most dimensionally stable among elastomers

Addition silicones

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Silicones
Powder/filler:____
Catalyst:____

Silica

Tin octoate

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Polyether
Base:___
Catalyst:____

Polyether

Alkyl-aromatic sulfonate

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Dehydrate form of gypsum

Calcium sulfate hemihydrate

Plaster of paris aka

Beta calcium sulfate hemihydrate

Type I plaster of paris

Impression plaster

Type II plaster of paris

Model plaster or study cast

Type IV gypsum

High strength stone (die stone)

Type III gypsum

Dental stone or alpha calcium sulphate hemihydrate

Gypsum retarder (2)

Borax | Na citrate

Gypsum accelerator (3)

Gypsum Potassium sulfate Sodium chloride

Investment for cast gold

Gypsum bonded investment

Imvestment for cast cobalt chromium

Phosphate bonded investment

Wax for bite wax

Corrective wax

Wax for boxing wax sticky wax and utility wax

Processing wax

Wax for inlay crowns rpd wax casting wax

Pattern wax

Natural waxes used in dental waxes are (3)

Paraffin Beeswax Carnauba

Tendency of molecule to expand or shrink depending on the temp

Coef of thermal expansiom

Best way to prevent warpage of patterns is to

Invest immediately

Best thing to do preserve dimension

Refrigerate - shrink place room temp then invest

Principal component of pattern waxes

Paraffin

Hardest structure in the world

Diamond

High noble aka Content (2) Examples (4)

Precious metal >=60% noble metal >=40% gold Silver Platinum Palladium Titanium

Noble aka | Content???

Semiprecious | >=25% noble

Base dental alloy aka | Content

Non-precious | <=25%

Hardest component used in dent (3)

Porcelain Gold Acrylic

Resistance to breaking under compressiom

Compressive strength

Resistance to breaking under tension

Tensile strength

Resistance to breaking or slide under horizontal forces

Shear strength

Max stress before fracturing

Ultimate tensile strength

Most important, resistance to permanent deformation

Yield strength

Rigidity or stiffness

Modulus of stiffness

Important for wear characteristics and finishing

Hardness

Change in length per 1 degree celcius change in temp

CTE

Process of joining two piece metal together through the use of lower fusing intermediate metal

Solder

Fusion temp p

100-150 degree F

Optimal space for solder

0.25 mm

Added to metal to improve flow of solder, dissolves oxides and prevent contaminatiom

Flux

Placed around the area that is to be soldered to restrict flow

Antiflux

Flame with excessive oxygen that produces oxide

Oxidizing

Flame with low oxygen. That produces carbon in metal

Reducing

Flame with balance oxygen levels

Neutral

Most common anti flux

Soft graphite pencil

Flame best to use with cast gold resto

Blue correct Boards is REDUCING FLAME

Exposure of walls of prep to a fluid

Percolation

Principal component of dental porcelain

Feldspar

Act as matrix in dent porcelain

Feldspar

Provides skeleton and strength | Filler of porcelain

Quartz

Clay that acts as a binder opaquer and flux

Kaolin

Properties of dental porcelain (2)

CS> tensile or shear | Low plastic deformation

Saturation of hue

Chroma

Lightness or whiteness or darkness or blackness

Value

Actual color

Hue

Other component of ZOE that increases strength

Ethoxy benzoic acid

First cement that bond to tooth structure | Faster setting than zinc phosphate

Zinc polycarboxylate

Powder and liquid of zn phosphate cement

Zinc xodie | Orthophoshoric acid

Only cement that is basic

CaOH

Most soluble cement

Silicate

Least soluble cement

gi cement

First cement to the release fluoride

Silicate cements

GIC principal fluid

Polyacrylic acid

Zinc silicophosphate powder and liquid

Zinc phosphate and silicate | Phosphoric acid