Dental waxes / endodontics courses

INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
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ContentsContents
 IntroductionIntroduction
 HistoryHistory
 Classification of waxClassification of wax
 Structure of waxesStructure of waxes
 Characteristics of individual waxesCharacteristics of individual waxes
 Properties of waxesProperties of waxes
 Inlay wax in detailInlay wax in detail
 CompositionComposition
 Ideal requirementsIdeal requirements
 Fabrication of wax patternFabrication of wax pattern
Direct techniqueDirect technique
Indirect techniqueIndirect technique
 DistortionDistortion
Inside the oral cavityInside the oral cavity
In lab proceduresIn lab procedures
PreventionPrevention
www.indiandentalacademy.comwww.indiandentalacademy.com

•Sticky wax
•Studies
•Conclusion
•References
ContentsContents

 FIRST INLAY IN DENTISTRY IS CREDITED TO “JOHNFIRST INLAY IN DENTISTRY IS CREDITED TO “JOHN
MURPHY” OF LONDON,WHO WAS FABRICATINGMURPHY” OF LONDON,WHO WAS FABRICATING
PORCELAIN INLAY IN 1855.PORCELAIN INLAY IN 1855.
 IN 1880, AMES OF SWASERY USED A BURNISHED-IN 1880, AMES OF SWASERY USED A BURNISHED-
FOIL TECHNIQUE FOR FABRICATION OF INLAYS.FOIL TECHNIQUE FOR FABRICATION OF INLAYS.
 FIRST CAST INLAY IS ATTRIBUTED TOFIRST CAST INLAY IS ATTRIBUTED TO
“PHILBROOK”-1897“PHILBROOK”-1897
 ““TAGGART” IN 1907 WHO INTRODUCED LOST WAXTAGGART” IN 1907 WHO INTRODUCED LOST WAX
TECHNIQUETECHNIQUE..
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 ACCORDING TO ANUSAVICEACCORDING TO ANUSAVICE——
““A LOW MOLECULAR WEIGHTA LOW MOLECULAR WEIGHT
ESTER OF FATTY ACIDS WITHESTER OF FATTY ACIDS WITH
MONOHYDRATE ALCOHOLMONOHYDRATE ALCOHOL
DERIVED FROM NATURAL ANDDERIVED FROM NATURAL AND
SYNTHETIC COMPONENTS SUCHSYNTHETIC COMPONENTS SUCH
AS PETROLEUM DERIVATIVESAS PETROLEUM DERIVATIVES
THAT SOFTENS TO A PLASTICTHAT SOFTENS TO A PLASTIC
STATE AT A RELATIVELY LOWSTATE AT A RELATIVELY LOW
TEMPERATURE “.TEMPERATURE “.
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CLASSIFICATION
CONSTITUENTS CONSISTENCY USES

Natural waxes
Mineral
Paraffin
Microcrystalline
BamsdahI
Ozokerite
CereSin
Montan
Plant
Carnauba
Ouricury
Candelilla
Japan wax
Cocoa butter
Insect
Beeswax
Animal
Spermaceti
Synthetic Waxes AdditivesCC
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Acrawax
Aerosol-OT
Castor wax
Flexowax
Epolene
Albacer
Aldo-33
Durawax
Stearic acid
Glyceryl –
Tistearate
Oils
Turpentine
Colorants
Natural resins
Rosin
copal
dammar
shellac
Synthetic resins
poly-
-styrene

PATTERNPATTERN PROCESSINGPROCESSING IMPRESSIONIMPRESSION
 inlay boxinginlay boxing
correctivecorrective
 casting utility bitecasting utility bite
 sheet stickysheet sticky
ready shapesready shapes
wax upwax up
 base platebase plate

 IN MOST MINERAL WAXES HYDROCARBONSIN MOST MINERAL WAXES HYDROCARBONS
RANGING FROM 17 – 44.RANGING FROM 17 – 44.
 IN PLANT WAXES SATURATED ALKANESIN PLANT WAXES SATURATED ALKANES
FROM 19 – 31.FROM 19 – 31.
THEREFORE DENTAL WAXESTHEREFORE DENTAL WAXES
CONTAIN MOLECULES HAVING ACONTAIN MOLECULES HAVING A
RANGE OF MOLECULARRANGE OF MOLECULAR
WEIGHTS THAT EFFECT THEWEIGHTS THAT EFFECT THE
MELTING AND FLOW PROPERTIESMELTING AND FLOW PROPERTIES
OF THE WAXES.OF THE WAXES.
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WaxWax TypeType MeltingMelting
rangerange
CharacteristicsCharacteristics
ParaffinParaffin straight chainstraight chain
hydrocarbonhydrocarbon
with 26-30 cwith 26-30 c
carbon atomscarbon atoms
40-7140-71 No valueNo value
MicrocrystMicrocryst
allinealline
Branched chainBranched chain
hydrocarbonhydrocarbon
with 41-50with 41-50
carbon atomscarbon atoms
60-9160-91 Les volumetricLes volumetric
change duringchange during
solidificationsolidification
BarnsdahlBarnsdahl Microcrystalline waxMicrocrystalline wax 70-7470-74 increases meltingincreases melting
range andrange and
hardness,hardness,
reduces flowreduces flow
OzokeriteOzokerite MicrocrystallineMicrocrystalline
wax, straightwax, straight
branched andbranched and
closed chainclosed chain
hydrocarbonshydrocarbons
6565 5-15% greatly5-15% greatly
improvesimproves
physicalphysical
characteristics incharacteristics in
melting rangemelting range
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WAXESWAXES

CeresinCeresin Straight andStraight and
branched chainbranched chain
paraffinsparaffins
---- Higher molecular wt.Higher molecular wt.
,hardness,and,hardness,and
melting rangemelting range
MontanMontan Long chain estersLong chain esters
with 40-58with 40-58
carboncarbon
atoms,alcohols..atoms,alcohols..
72-9272-92 Improves hardnessImproves hardness
and melting rangeand melting range
Substituted for plantSubstituted for plant
waxeswaxes
CarnaubaCarnauba Esters, alcohols,Esters, alcohols,
acids,acids,
hydrocarbonshydrocarbons
84-9184-91 Increases meltingIncreases melting
range andrange and
hardnesshardness
CandellilaCandellila ---- 68-7568-75 Increases hardnessIncreases hardness
Japan waxJapan wax Fats-glycerides ofFats-glycerides of
palmitic andpalmitic and
stearic acidsstearic acids
5151 Improves tackinessImproves tackiness
and emulsifyingand emulsifying
abilityability
CocoaCocoa
butterbutter
Fats-glyserides ofFats-glyserides of
palmitic acidpalmitic acid
and stearic,and stearic,
oleic acidsoleic acids
---- Same as above alsoSame as above also
protects againstprotects against
dehydration of softdehydration of soft
tissues and totissues and to
protect GICprotect GIC
productsproducts
BeeswaxBeeswax Esters-mycicylEsters-mycicyl
palmitate,organipalmitate,organi
63-7063-70 Main component inMain component in
sticky waxsticky wax
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TYPETYPE USESUSES
BOXINGBOXING TO BUILD UP VERTICAL WALLS AROUNDTO BUILD UP VERTICAL WALLS AROUND
IMPRESSION TO PRODUCE DESIRED SIZE ANDIMPRESSION TO PRODUCE DESIRED SIZE AND
FORM OF BASE CAST.FORM OF BASE CAST.
BASE PLATEBASE PLATE TO ESTABLISH THE INITIAL ARCH FORM,TO ESTABLISH THE INITIAL ARCH FORM,
VERTICAL DIMENSION AND PLANE OFVERTICAL DIMENSION AND PLANE OF
OCCLUSION BY USING AS A TRAYOCCLUSION BY USING AS A TRAY
UTILITYUTILITY TO PREPARE A DESIRABLE CONTOUR TO ATO PREPARE A DESIRABLE CONTOUR TO A
PERFORATED TRAY FOR USE WITHPERFORATED TRAY FOR USE WITH
HYDROCOLOIDS.HYDROCOLOIDS.
CASTINGCASTING TO PREPARE PATERN FOR METTALICTO PREPARE PATERN FOR METTALIC
FRAMEWORK OF R.P.DFRAMEWORK OF R.P.D
STICKYSTICKY FOR JOINING METAL PARTS BEFOREFOR JOINING METAL PARTS BEFORE
SOLDERING AND FOR JOINING FRAGMENTS OFSOLDERING AND FOR JOINING FRAGMENTS OF
BROKEN DENTURES BEFORE REPAIRBROKEN DENTURES BEFORE REPAIR
IMPRESSIONIMPRESSION TO RECORD NON-UNDERCUT EDENTULOUSTO RECORD NON-UNDERCUT EDENTULOUS
PORTION OF THE MOUHPORTION OF THE MOUH

1) MELTING RANGE1) MELTING RANGE :
Because waxes may contain several types of
molecules, each having a range of molecular
weights, they have melting ranges rather than
melting points.
The melting ranges of a paraffin wax, a carnauba
wax and a mixture of these two waxes is illustrated
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2)THERMAL EXPANSION2)THERMAL EXPANSION
 Dental waxes and their components have the highestDental waxes and their components have the highest
coffecient of thermal expansion of any material used incoffecient of thermal expansion of any material used in
restorative dentistry.restorative dentistry.
 Mineral waxes have higher coeff than plant waxesMineral waxes have higher coeff than plant waxes..
 Now the linear thermal expansion of waxes may beNow the linear thermal expansion of waxes may be
explained on the basis of two featuresexplained on the basis of two features

THERMAL PROPERTIESTHERMAL PROPERTIES
SECONDARYSECONDARY
VALENCEVALENCE
FORCESFORCES
TRANSITIONTRANSITION
POINTSPOINTS

MINERALMINERAL PLANTPLANT
expand more because they have
weak Secondary valence forces
which are easily overcome by the
energy absorbed during a rise in
temperature. This permits more
movement of the wax
components, thus allowing a
greater amount of thermal
expansion.
have high secondary
valence forces because of
their high concentrations
of esters. Because the
secondary valence forces
restrict the movement of
the wax components, small
coefficients of thermal
expansion are observed.

stable crystal lattice form commences to change to astable crystal lattice form commences to change to a
hexagonal form below the melting range of wax. It ishexagonal form below the melting range of wax. It is
during this progressive change that waxes are able toduring this progressive change that waxes are able to
be manipulated without flaking, tearing or undulybe manipulated without flaking, tearing or unduly
stressed.stressed.
AT LEAST TWO RATES OF TRANSITIONS BETWEENAT LEAST TWO RATES OF TRANSITIONS BETWEEN
22-52 C22-52 C
AT THESE POINT INTERNAL STRUCTURAL PARTSAT THESE POINT INTERNAL STRUCTURAL PARTS
ARE FREE TO MOVEARE FREE TO MOVE

Clinical importanceClinical importance :
Because the coefficient of thermal expansion of
INLAY WAX is so great temperature changes in
wax patterns after the critical dimensional
relationships are set may be a major contributing
factor in inaccuracy of the finished restoration.
Cooling from 37 C to 20 C a linear shrinkage of
0.6% can occur for a wax with a coefficient of
thermal expansion of 350 x 10-6 /C.

COMPRESSIVECOMPRESSIVE
STRENGTHSTRENGTH
ELASTICELASTIC
MODULUSMODULUS
PROPOTIONALPROPOTIONAL
LIMITLIMIT

Elastic modulus of carnauba wax decreased from 1790
to 760 Mpa from 23 C to 37 C. Paraffin wax showed on
sharp decrease in modulus from 310 to 28 MPa between
23 C and 30 C. Inlay wax which simulates a mixture of
75% paraffin and 25% carnauba has intermediate
changes in modulus of 760 to 48 MPa between 23 C and
40 C. www.indiandentalacademy.comwww.indiandentalacademy.com

Clinical RelevanceClinical Relevance :
Modulus of inlay wax is important in the
hygroscopic expansion of casting investments in
which the wax patterns is subjected to stresses
resulting from the expansion of the investment
during setting . Nonuniform deformation of wax
pattern such as crowns can be minimized by
using waxes having different elastic moduli for
particular parts of the pattern.

 results from the slippage of molecules over each
other.
dependent on temperature of wax, force bringing about
deformation and time and force is applied.
Flow greatly increases as the melting point of the wax
is approached.
For inlay wax there should be :
A large flow at 5*C above mouth temperature, so that
good detail of the cavity will be obtained.
Negligible flow at 37*C, so that no distortion will occur
on removal of the pattern from the cavity.

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Essential ingredients of a successful inlay wax are
paraffin wax, gum dammar and carnauba wax with
some coloring material.
40-60%. It is derived
from the high boiling
fractions of petroleum.
Paraffin wax is
likely to flake
when it is trimmed
and it does not
present smooth,
glossy surface.
NO BODY IS PERFECTNO BODY IS PERFECT

Gum dammar or dammar resin is a natural resin.
It is added to the paraffin wax to improve the
smoothness in holding and to make resistant to
cracking and flaking. It also increases toughness
of the wax and it enhances the smoothens and
luster of the surface.
ACHIEVING PERFECTIONACHIEVING PERFECTION

Carnauba wax occurs as a fine powder on the leaves of
certain tropical palms.
quite hard.
Has relatively high melting point
combined with paraffin to decrease the flow at mouth
temperature.
Provides glossiness to the wax surface.
substitute– candellila wax
ADDED GLAMOURADDED GLAMOUR

IDEAL REQUIREMENTS OF INLAY WAX :IDEAL REQUIREMENTS OF INLAY WAX :
colour :contrast with the die material.
no flaking or surface roughening when the wax is bend
and molded after softening.
Should not be stickyShould not be sticky
should burn out,forming carbon, which is later eliminated.
rigid and dimensionally stable.
uniform

Direct wax pattern
prepared directly in
the prepared cavity
intra-orally is called
as “Direct Wax
Pattern” technique.
--type I wax is used
Indirect wax pattern
 “Indirect”.
Type II wax is used.
TECHNIQUESTECHNIQUES
Direct-indirect
Indirect-direct

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MATERIALMATERIAL
LOCATIONLOCATION
ANGULATIONANGULATION
 SIZESIZE
LENGTHLENGTH
SPRUE-WAX JOINTSPRUE-WAX JOINT
RESERVOIRRESERVOIR
SURFACE TREATMENTSURFACE TREATMENT

most serious problem to be faced
It results from thermal changes and release of stress.
stress relief is a function of the length of time during
which the pattern is stored and is also influenced by
temperature at which the pattern is stored.

CARVINGCARVING
ANDAND
REMOVALREMOVAL
THERMALTHERMAL
CONDUCTIVITYCONDUCTIVITY
ELASTICELASTIC
MEMORYMEMORY

COOL BY ITSELF
AVOID TOUCHING
INVEST IMMEDIATELY

WAX SHRINKAGE
GOLD SHRINKAGE
I WANNA
GROW
UP!!

WAX
SHRINKAGE
+
GOLD
SHRINKAGE
WAX
EXPANSION
SETTING
EXPANSION
HYGROSCOPIC
EXPANSION
THERMAL
EXPANSION
+
+

TO AID IN ENLARGING THE MOULD
DEPENDS ON THERMAL
EXPANSION BY EXOTHERMIC
HEAT..

CONTROL OF
SETTING EXPANSION
ACCELERATORSACCELERATORS RETARDERSRETARDERS

SILICA
TIME OF
IMMSERSION

700* C

sticky adheres closely to the surfaces on which it
is applied.
the wax is firm, free from tackiness, and brittle.
 should fracture rather than flow if it is deformed during
soldering or repair procedures.
used to assemble metallic or resin pieces in a fixed
temporary position, it is primarily used on dental stones and
plasters. www.indiandentalacademy.comwww.indiandentalacademy.com

 Effect of selected physical properties of waxes on
investments and casting shrinkage—journal of
prosthodontics, feb 1996;75;211-216

Relationship between flow characteristics,bending strength,
and softening temperature of paraffin and dental inlay
waxes to casting shrinkage when patterns were invested
with a phosphate bonded investment.findings of study are
—
a) Casting shrinkage decreased when the flow of the wax
pattern increased.
b) The flow of the wax pattern increased as the exothermic
reaction increased.
c) A larger casting ring is suggested for castings when a
relatively thick wax pattern or an inlay wax that has a
high strength, softening temperature,and low flow
percentage is used.
d) The industrial waxes,waxes 1 through 3,demonstrated
potential to be used for dental castings,but more research is
needed.

 The distortion of the wax pattern after its removalThe distortion of the wax pattern after its removal
from the cavity is a function of temperature andfrom the cavity is a function of temperature and
time interval before investing. The nearer thetime interval before investing. The nearer the
softening point of the wax is approached, the moresoftening point of the wax is approached, the more
readily the stress is released. Longer a pattern isreadily the stress is released. Longer a pattern is
allowed to remain before investing, greater theallowed to remain before investing, greater the
deformation that may occur even at roomdeformation that may occur even at room
temperature.temperature.
 Therefore a pattern should be invested as soon asTherefore a pattern should be invested as soon as
possible after its removal from the cavity / die. Inpossible after its removal from the cavity / die. In
any case pattern should not stand for more thanany case pattern should not stand for more than
20-30 minute before being invested.20-30 minute before being invested.
 Although distortion causes defects in casting, its aAlthough distortion causes defects in casting, its a
serious problem and also it is very techniqueserious problem and also it is very technique
sensitive procedure, where we can minimize thesensitive procedure, where we can minimize the
amount of distortion but cannot eliminate totally.amount of distortion but cannot eliminate totally.

Anusavice – Science of Dental Materials.
M.A. Marzouk – Modern Theory and
Practice
Sturdevant, 5th
Edition, Art and Science of
Operative Dentistry.
Craig : Dental Materials Properties and
Manipulation.
McCabe : Applied Dental Materials
Rosentiel : Prosthodontics.
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Effect of selected physical properties of waxes on
investments and casting shrinkage. J Prosthet Dent
1996;75(2):211-216.
Rheology of dental waxes. Dent Materials 2000;16(5):337-
350.
Distortion of wax crowns. Scand J Dent 1984;92(3):253-
256.
Wetting effects of surface treatments on inlay-wax
investment combinations. J Dent Res. 1981;60.
J Am Dent Association. Revised ADA Specification No.4
for inlay wax 1984;108:88.
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