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thermoplastic molding material.thermoplastic molding material.solid at room temperature.solid at room temperature.

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- Baseplate wax: sheets, establish initial arch form in construction of CD.

- Bite wax: record the occlusal surfaces of teeth.

- Boxing wax: sheet wax used as a border of an impression to provide base of the cast to be made.

- Inlay wax: applied to dies to form direct or indirect patterns for the lost-wax tech.

- Sticky wax: adheres to dry clean surfaces.3

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BASE Wax: BASE Wax: that is almost always paraffin (not smooth, not glossy, flake when trimmed)

(1) (1) Hydrocarbon of paraffin or esters Hydrocarbon of paraffin or esters (2) (2) High or low MWHigh or low MWMODIFIERMODIFIER Waxes Waxes: : contribute properties such

as increased hardness, stickiness, or brittleness(1) Hydrocarbon or ester types; (1) Hydrocarbon or ester types; (2) High or low MW(2) High or low MWCOLORANTCOLORANT: : 1% FillersFillers: some waxes contain it to control : some waxes contain it to control

expansion and shrinkage of the wax expansion and shrinkage of the wax product. product.

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Natural (mineral, vegetable, or animal origin and/or synthetic waxes (more homogeneous & pure)

Natural waxes are complex combinations of organic compounds of high molecular weight:

Hydrocarbons,e.g. saturated alkanes, & microcrystalline wax series, carnauba wax, candelilla wax.

Esters, e.g.myricylpalmitate.

Some waxes also contain free alcohol and acid.

(Esters are formed from union of higher fatty acids with higher aliphatic alcohol with elimination of water)

Alcohol+Fatty Acid Ester+Water 7

Natural waxes Synthetic waxes AdditivesMinerals: Paraffin Microcrystalline Barns Dahl Ozokerite Ceresin Montan

Acrawax CAerosol,OTCastorwaxFlexowax CEpolene N-10AlbacerAldo 33Durawax 1032

FatsStearic acidGlyceryltristearate

OilsTurpentineColor

Plants :Carnauba Ouricury Candelilla Japan wax Coca butter

Natural ResinsRosinCopalDammarSandaracMastin, Shellac Kauri

Insect: Beeswax

Animal: Spermaceti

Synthetic ResinsElvaxPolyethylene Polystyrene8

Gum dammar: smoothness, resistant to flaking, toughness. (resin)

Ceresin the hardness and water resistance of wax. Improves carving properties.

Carnuba the hardness and water resistance, melting range, gives glossiness, flow at mouth temp.

Beeswax the stickiness, improves flow properties at mouth temperature. (esters)

Rosin the brittleness. (resin)Microcrystalline waxes stress release

on cooling. 9

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Occurs because of the Multiple wax mixturesThe liquidus line (representing the

temperature at which complete melting has occurred)

The solidus line (below which the composition is entirely solid)

the solid + liquid range in between is quite broad (almost 40°C). To allow manipulation

To develop wax flow, the temperature only needs to be heated to a point within the solid+liquid range or up to the point of the liquidus line but not much higher.

Excessive heating would cause decomposition.

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COMPOSITION (%)

TE

MP

ER

AT

UR

E (

C)

Paraffin Carnuba

40

30

20

60

50

70

80

90

25 50 75 100

LIQUID

LIQUID + SOLID

SOLID

Melting Onset (Solidus)

Melting Completion (Liquidus)

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Name: Origin: Composition: Melting(C)

Density(20C)

PARAFFIN Mineral Hydrocarbon mixture 50-57 0.90

CERESIN Mineral Complex hydrocarbons 61-78 0.91-0.92

BEESWAX Animal Ester mixture 62-65 0.95-0.96

CANDELILLA Plant C21 hydrocarbons 68-70 0.95-0.99

CARNAUBA Plant Hydrocarbon, Ester, Fatty Acid

82-86 0.99-0.999

GUMDAMMAR

Plant Aromatic resin ca 120 1.040-1.120

ROSIN Plant Aromatic resin acid 100-150 1.08

Methods:1. Flame heated instruments2. warmth of hand??3. dry heat as wax pot4. Water bath, but not for inlay wax??

Flow : after the highest melting point is reached. Temperature 1/ viscosity Flow temperature must be > mouth temp if

needed in solid state

Over heating should be avoided?the base or modifier waxes can be decomposed.

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In solids its analogous to creepIn liquids its analogous to viscosityWaxes are usually non-flowable at room

temperatureTemperature 1/ viscosityIt is critical for inlay wax to have flow less

than 1%

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It is lowWax should be softened evenly by

rotation above the flame until it evenly softens or flows

Tempered in a water bath alternately with the flame heating to allow the core to soften before dripping

If a soft core of a bulk of wax is to be made, roll the wax when it is in softened status – (unable to hold shape by itself)

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Used with cast metal techniquesWax patterns need to be burned to

the point where no excess residue may interfere with metal casting

Heat melt and/or decompose wax by the process of oxidation which completely transform it into water vapor and carbon dioxide so that no residue is left.

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Created by the bees wax addition in the mixture

Increased if material is warmed by hand

Solid waxes become tacky to other material if heated

Adhesives may be applied on casts before wax application

Wax dipping in bees wax increase stickiness of refractory casts

Old wax adheres to new one if surface is dry

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Wax should be dimensionally stable once it has solidified (less than 1%). Invest the pattern immediately after removal from the die.

Deformations:Plastic deformation

Under force is by ductility. Ductility allows it to be

carved or burnished Residual stress recovery Elastic Recovery

Residual stress reduction Heat material evenlyFollow manufacturer instructions Invest within 30 min of carving Whenever wax additions are cooled.

The exterior surface tends to cool first. The molten interior slowly solidifies and contracts. This encourages distortion or flow. Add in small increments, layering

Store at low temperatures

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Very high

ceramics (1-15 ppm/°C)metals (10-30 ppm/°C)waxes (30-600 ppm/°C)inlay wax (250-300 ppm/°C) ( wax pattern made in the

mouth will shrink appreciably)

Residual thermal stresses may change dimensions

Paraffin > beeswax >carnuba

Do not heat above melting point during work

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250ppm/C

Par

affi

n

Carnuba

Bee

swax

0 25 30 40 4535 500

1.2

1.0

0.8

0.6

0.4

0.2

TEMPERATURE (C)

EX

PA

NS

ION

(%

)KERRHARDWAX

Wax is hydrophobicTo increase its wetting a surfactant could be

sprayed over wax to increase flow of investment material

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Coloring is not standardizedDark colors provide good color contrast for

processing wax Opaque and Tooth-colored waxes provide

good material for esthetic case presentations and patient education

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Usesmetal castings of

InlaysAttachmentsCrownsPonticsPartial dentures

Denture base material

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Formssticks pallets, tins-Blue or green

Consistencies-Hard, medium, soft, regular

Application -indirect and direct technique

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RemovableRemovableDie withDie withWaxed InlayWaxed Inlay

CompositionParaffin + Carnuba + Ceresin +Beeswax + Colorants

Properties-low thermal dimensional change

-flow temp higher than mouth-must have clean excess residue

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ApplicationUsed for metal frameworkcomplete and partial dentures

FormsSheets and preformed shapes

Propertieslow thermal dimensional changemust have clean excess residue

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Formsheets Types I, II & III Application-wax registration of ridge form-Carved into tissue forms and Support teeth-Bite registration Properties-melting range higher than mouth temperature-Customised to climate

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UsesFor edentulous impressions Corrects undercutsCloses bubbles

Propertiesflow at mouth temperature E.g. Bite wax, mizzy

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Uses To articulate

models correctlyForms horse shoe shapeMay be supported

by metal foil for stability

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Forms 1 inch sheetsUses used to form base of the cast pouringMay be used to modify borders of trays PropertiesTacky at room temp

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Transfer to impressionTransfer to impression

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Forms Ropes manipulated at room tempApplicationsAdd to the tray

- customize for pt mouth- Comfort from sharp edges- Control imp material in mouth

-Cover ortho bands and wires- to register the bite-Block out undercuts

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FormsPencil shapeorange or yellow Propertieshard and brittle – can reorient if brokenAdhere temporarily the metal, gypsum, resin – for fabrication or repair

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Thank you