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Dental Dentalwaxeswaxes

Dental waxes Dental waxes

• Waxes have several applications indentistry.

Components of dental waxes Components of dental waxes

Natural wa xes

Synthetic w axes

Additives

•Mineral•Plant•Insect•Animal

•Acrawax C• Aerosol O T•Castorwax• Aldo 33

• Stearic acid•Oils•Colorants•Resins

Natural waxes Natural waxes

Complex combination of organic compound s of high molecular weights.

Two principle groups of organic compounds contained in waxes are-

HYDROCARBONS &ESTERS

Natural waxes Natural waxes

• Mineral waxes-distillation product of petroleum • Parrain• Microcrystalline• Barnsdahl• Ozokerite• Ceresin• Montan

Plant waxesEg)carnaubua wax-occurs as fine powders on leaves of certain tropical plants

Insect waxEg –bee wax

Synthetic waxes Synthetic waxesNatural waxes are not consistent in their

composition and properties, so to overcome this synthetic waxes are used.

• They are highly refined Acrawax C• Eg)• Aerosol OT• Castorwax• Aldo 33

Wax additivesWax additives• Fats• Oils• Resins• Gums- to improve the properties of

wax

FatsFats• Increase the melting range and the ha

rdness of compound waxes.

OilsOils• Hydrocarbon oils - soften mixture of w

axes.

• Silicone oils - improve the ease of poli shing with waxes.

ResinsResins

• Most natural resins are obtained from trees and plants.

• improve toughness, hardness, meltin g range of waxes

Properties Properties of of waxes waxes

Melting range Melting range

• They have melting range rather than m

elting point.• Mixing of waxes change their melting

range

Thermal expansion Thermal expansion

• Expand when temp. is risen

• Contract when temp. is decreased

• Dental waxes have the largest coefficient of thermal expansion.

Mechanical properties Mechanical properties

• The elastic modulus, proportional limit and compressive strength of waxes are low compare with those of other materi

als and these properties depend strong ly on the temperature.

FlowFlow• Flow is dependent on the temp. of the

waxes.

• Flow is greatly increase as the melting point of the wax is approached.

DuctilityDuctility

• Ductility increase as the temp of a wax is increase

• Waxes with lower melting temp. have a g reater ductility.

• The highly refined waxes is quite brittle

- Dental wax Classification - Dental wax Classification

• Pattern waxes• Processing waxes• Impression waxes

Pattern wax Pattern wax• An artificial dental restoration is first made

with pattern wax,whch is later replaced with permanent material eg)cast gold alloys, co-cr-ni alloys or poly methyl methacrylate resin

1)1) Pattern wax Pattern waxeses

1. Inlay waxes

3. Baseplate waxes2. Casting waxes

2)2) Processing wax Processing wax

• Used primarily as auxillary aids in th e construction a variety of restoratio

ns and appliances either clinically or in the laboratory

Processing waxes Processing waxes

1. Boxing waxes

2. Utility waxes

3. Sticky waxes

4. Carding waxes

3)3) Impression waxes Impression waxes

• Used for taking impression within the mouth.

– Bite registration waxes– Corrective waxes

Korecta wax

Alu wax

1. Inlay waxes

Inlay wax Inlay wax :: CCompositionomposition

Paraffin (major portion)

Microcrystalline waxCeresin

CarnaubaCandelillaBeeswax

Inlay waxes generally are produced in deep blue , green , or purple rods or sticks.

The flow can be reduced by adding more carnueba wax o r by selecting

higher melting paraffin waxes.

Inlay pattern wax Inlay pattern wax

• A pattern of the wax is first constructed in inlay wax .

Inlay pattern wax Inlay pattern wax

• The pattern then is embedded in a gyp- sum silica investment material to form

a mold with an ingate or sprue leading from the outer surface of the investme

nt mold to the pattern.

Inlay pattern wax Inlay pattern wax

• The wax is subsequently eliminated by h eating & softening and the mold is furthe

r conditioned to receive the molten metal.

Inlay pattern wax Inlay pattern wax

Inlay waxes : Properties Inlay waxes : Properties

ANSI/ADA Specification No. 4 for denta l inlay casting wax.

Type I wax = a hard wax that is prescribe d for forming direct patterns in the mouth.

Type II wax = a softer wax that is used as an indirect technique wax.

FlowFlow The working temperature for making direc

t wax pattern must not to be so high as to cause damage to the vital tooth structure.

At mouth temp., direct inlay wax must hav e essentially no flow to minimize the possi

bility of distortion of the pattern during re moval from the tooth cavity.

Casting wax Casting wax

The pattern for the metallic framework of r emovable partial denture and other similar structures is fabricated from the casting wa

xes.

Casting wax : Casting wax : CCompositionomposition

The ingredients are similar to tho se found in inlay waxes.

Baseplate wax Baseplate wax

Baseplate wax derives its name fro m its use on the baseplate tray in th

e technique for complete denture r estoration.

It’s normally pink color.

Baseplate wax Baseplate wax

Baseplate wax : Baseplate wax : CCompositionomposition

- 70 80 % paraffin or ceresin small quantities of other waxes & additi

ves. typical composition

– - 80 12% ceresin % beeswax– 25. % carnuaba– 3% natural or synthetic resins– 25. % microcrystalline or synthetic wax

Baseplate wax : Baseplate wax : PPropertiesroperties

ANSI/ADA Specification No.24– Type I - Soft, building contours and

veneers– Type II - Medium, patterns in mouth, normal climates– Type III - Hard, patterns in mouth,

in tropical climates

Linear thermal expansion from 25o-40oC < 08. %

Softened sheets shall cohere readily witho ut becoming flaky or adhering to fingers No irritation of oral tissue

trim easily with a sharp instrument at 23oC

Practical requirements Practical requirements

Smooth surface after gentle flaming No residue on porcelain or plastic teeth

Coloring shall not separate or impregnat e plaster during processing

No adhesion to other sheets of wax or se parating paper on storage

Practical requirements Practical requirements

Beading &Beading & Boxing wax Boxing waxUsed to build up vertical walls around the

impression,in oder to pour the stone and make the cast

ADVANTAGES OF BEADING & BOXING

1)Preserves the extensions & landmarks

2)Controls the thickness of borders

3)Controls the form and thickness of the base of cast

4)Conserves the artificial stone

Boxing wax: Boxing wax: WW orking properties orking properties

- -Federal specification No U W 138 Smooth, glossy surface on flaming

Pliable at21o C , retain shape at35

o C

Seals easily to plaster with hot spatula

Utility wax Utility wax

Used in numerous instance most likely consists of beeswax, petrola

tum and other soft waxes

Used to adjust contour of perforated tray for the use with hydrocolloid(to raise flange height, to extend the tray posteriorly and to raise palatal portion of the tray in case of deep palate)

Sticky wax Sticky wax

It is sticky when melt and adheres closely t o the surface on which it is applied. It is firm, free from tackiness and brittle at

room temp. Rosin & yellow beeswax are the usual majo

r constituents.

Used for assembling/joining metal parts before soldering and for joining fragments of broken repair procedure

Corrective impression wax Corrective impression wax

Used as a wax veneer over an original imp ression to contact and register the detail o

f the soft tissue .To record posterior palatal seal in dentures

Formulated from hydrocarbon waxes such as paraffin,ceresin & beeswax and may co

ntain metal particles

The flow at37o

C is 100%

Corrective impression wax Corrective impression wax

Bite registration wax Bite registration wax

Used to record the relationship bwn upper and lower teeth .this is necessary to mount cast correctly in articulator

Formulated from beeswax or hydro carbon waxes such as paraffin or ce

resin and contain alumina or coppe r particle

Bite registration wax Bite registration wax

• Alu wax

Bite registration wax Bite registration wax

• Occlusal indicator wax