Dental Casting Waxes

1. DENTAL CASTING WAXES

2. CONTENTS
• INTRODUCTION
• Classification of waxes
1) According to origin
2) According to use and application
• Inlay casting waxes
1) Composition
2) Properties
• Casting waxes
• Review of literature
• Conclusion
• References

3. INTRODUCTION
• Over 4000, years ago in Mesopotamia………natural bees wax was used for
patterns.
• The investment casting has been used in the arts by
many civilization.
• The technique was largely ignored ,until the dawn of
twentieth century, when it was rediscovered by dental
profession for producing crowns and inlays.

4. • Waxes were first used in dentistry in early
eighteenth century………..edentulous impressions.
• Waxes are still employed in large quantities in
various clinical and lab procedure………patterns
for cast restoration, bite registration.
• Dr William.H.Taggart of Chicago formulated a
wax pattern compound of excellent properties.
• He also described an investment technique
,developed an investment material and even
invented an air pressure casting machine.

5. Waxes are organic polymers consisting of hydrocarbons and their
derivative (eg ester and alcohol).
ACCORDING TO GPT Casting waxes can be defined as a
composition containing various waxes with desired properties for
making wax patterns to be formulated into metal casting.

6. CLASSIFICATION OF WAXES
1)According to origin
2)According to use and application

7. ACCORDING TO ORIGIN
Natural Synthetic
Mineral
Paraffin, microcrystalline, ceresin Polyethylene waxes
Montan, Polyoxyethylene glycol
waxes
Plant
Carnauba, candelilla
Insect
Beeswax
Animal
Spermaceti wax

8. ACCORDING TO USE AND & APPLICATION
PATTERN WAXES PROCESSING WAXES IMPRESSION WAXES
Inlay wax Boxing wax Bite registration or
Casting wax utility wax corrective wax
Base plate wax sticky wax
carding wax
Blockout wax
white wax

9. INLAY CASTING WAX
• Inlay wax is a specialized dental wax that can be applied to dies to
form direct or indirect patterns for the lost wax technique used for
casting metal or hot pressing of ceramics.
• Generally produced in deep blue, green or purple color.
• Composition of inlay wax
Paraffin-60%
Carnauba-25%
Beeswax-5%
Ceresin-10%
Natural resins(gum dammer)-less than 1%
Organic fillers- added to avoid excessive shrinkage,expansion due
to temp change
Microcrystalline wax- In minute amount.
Candelilla
Coloring agents

10. Paraffin wax(mineral wax)
• Generally the main ingredient of inlay waxes.
• Obtained from high boiling fractions of petrolem(methane series)
• Mixture of hydrocarbons
• Melting range 40-71o C. increases with increasing molecular wt.
• Paraffin waxes have less than 0.5% oil.
• Presence of oil lowers melting temp.
• During solidification and cooling a volumetric contraction in the
range 11%-15%.
• This is not uniform ,since it is a mixture of hydrocarbons.
• Likely to flake when trimmed.
• Does not present smooth, glossy surface
• Consequently other waxes and natural resins are added.

11. Carnauba wax (plant wax)
• Derived from tropical palms
• It is quite hard, melting range 84-910C
• Combined with paraffin to-
Decrease flow at mouth temp
increase the hardness
• It contributes to glossiness of the wax surface, even more than
dammar resin.
(Addition of 10 % carnauba wax to paraffin wax with a melting range
of 200C will increase the melting range to 460C.)

12. Ceresin wax (mineral wax)
• May replace part of paraffin to modify toughness and carving
characteristic.
• Like microcrystalline waxes they are branched chain and straight
chain paraffin.
• They have higher mol wt and greater hardness than hydrocarbon
waxes
• These waxes also may be used to increase the melting range of
paraffin waxes.

13. Beeswax (insect wax)
• Complex mixture of esters, consisting mainly of myricyl palmitate,
plus saturated and unsaturated hydrocarbons and high molecular wt
organic acids.
• Melting range 63-700C
• Brittle at room temp, becomes plastic at body temp
• Used to modify the properties of paraffin wax
(also the main component of sticky wax)

14. Natural resin (gum dammer)
• Less than 1%
• Added to paraffin to improve its smoothness in molding
• It renders it more resistant to cracking and flaking
• Increases the toughness of the wax and enhances the smoothness
and lusture of the wax.
Microcrystalline waxes(mineral)
• Similar to paraffin waxes, but obtained from heavier oil fractions.
• It has a higher melting range 60-910C
• It is tougher and more flexible than paraffin
• It has less volumetric shrinkage during solidification than paraffin.

15. Candelilla wax (plant wax)
• Same qualities as carnauba wax
• Added to paraffin to partially or entirely replace carnauba wax.
• Its melting point is lower, and it is not as hard as carnauba wax.

16. Organic Fillers
• Normally soft wax shrinks more than hard wax
• High shrinking wax may cause significant pattern distortion when it
solidifies.
• For this reason organic filler is added , they should be completely
miscible with components of inlay wax.
• They should not leave an undesirable residue after burnout.

17. • In modern inlay waxes, carnauba wax is often replaced in part with
certain synthetic waxes that are compatible with paraffin wax
• One is a complex nitrogen derivative of higher fatty acids.
• The other is composed of esters of acids derived from montan wax,
a petroleum derivative
• Control of properties of inlay wax is governed by combination of
factors-
-Amount of carnauba wax used.
-The melting range of hydrocarbon wax.
-Presence of resin.

18. DENTARUM (Germany)
Crown and Bridge Inlay Wax
In ropes In bulk
Melting point 720C
Also present in ivory color melting point 730C

19. Also present in different colours
Vario wax set
Dark blue-hard, for crowns bridges and inlays. Add on and Dip use melting point 690C
Light blue-soft, for crowns bridges and inlays,add on and dip use melting point 720C
Lilac-stress free, for copings and cervical margins , melting point 790C
Red- adhesive, connecting and adhesive wax, melting point 700C

20. Cervical wax- for the cervical area, no shrinkage , a
Very accurate fit will be obtained, melting point 740C
Special wax for electrical wax heating unit(vario therm),dark blue-hard and light blue
soft are for modelling,trimming and dipping application, lilac-medium hard , red stress
Free for cervical margins, green-hard for trimming. Dip application yellow wax caps of
Uniform strength.

21. Wax Preforms are available (ceratom wax preforms, Dentaurum)
It simplifies wax up and shorten finishing procedure.

22. DESIRABLE PROPERTIES OF INLAY CASTING WAX
1) When softened the wax should be uniform.
It should be compounded with ingredients that blend with each
other so that there are no grainy areas or hard spots.
2) The color should be such that it contrasts with the die
material or prepared tooth.
It is necessary to carve the wax margins close to the die
Therefore a definite contrast in color facilitates proper finishing of
the margins.
3) There should be no flakiness or similar surface roughening
when the wax is bent and molded after softening
Such flakiness is likely to be present in paraffin wax , this is one of
the reasons modifiers are added.

23. 4) During carving wax should not pull away with carving
instrument or should not chip as it is carved.
Wax is carved at the margins so that the patterns conforms exactly
to the surface of the die, this procedure sometimes require that the
wax be carved to very thin layer.
5) Wax should burn out , forming carbon which is later
eliminated by oxidation to volatile gases.
ANSI/ADA specification No 4 requires that the melted wax when
vaporized at 5000C (9320F) , leave no solid residue in excess of
0.10% of the original wt of specimen.
6) The wax pattern should be completely rigid and
dimensionally stable at all times until it is eliminated .
wax pattern is subject to flow unless it is handled carefully , it is also
subject to relaxation , a factor that must be taken into consideration
in its manipulation.

24. PROPERTIES OF INLAY CASTING WAXES
FLOW
• ANSI/ADA Specification No 4 covers two types of waxes
• Type I is medium wax, its hard, used for direct pattern in the
mouth, where lower flow values at 370C tend to minimize any
distortion of the pattern on its removal.
• Type II is a soft wax used in indirect technique
• Flow at different temp when type I and II waxes are subjected to
19.6 N load for 10 min requirement for ANSI/ADA sp no 4(JADA 1984)
Type of wax T=300C T=370C T=400C T=400C T=450 T=450C
(max) (max) (min) (max) (min) (max)
I --- 1.0 --- 20 70 90
II 1.0 --- 50 --- 70 90
At body temp flow of type I is 1% and that of type II is 9%, to record cavity detail it
Must attain temp around 450C.

25. • Max flow permitted for type I waxes at 370C is 1%, the low flow at
this temp permits carving and removal of pattern from prepared
cavity at oral temp without distortion.
• Type II wax is a softer wax shows greater flow, it allows greater
ease of carving and molding, since it is used in indirect pattern
formation on die ,change of temp from oral cavity to room temp is
not a problem.
• Each wax exhibits sharp transition point, above which it loses its
plasticity, for soft waxes it is at lower temp, and hard waxes at a
higher temp.
• Waxes lack rigidity and may flow under stress even at room temp.
careful handling is necessary during manipulation.

26. THERMAL PROPERTIES
• Thermal conductivity of waxes is low and time is required to both
heat them uniformly and to cool them to body or room temperature.
• Inlay wax thermally expand and contract more per degree of temp
change than any other dental material.
• This is one of the inherent disadvantages of waxes when they are
used in the direct technique.
• This property is not significant when wax is used in indirect
technique because the pattern is not subjected to a change from
mouth to room temp, provided no marked variations in temp occurs
after the removal of pattern from die.

27. • Waxes have high coefficient of thermal expansion .
The max linear thermal expansion allowed between 25 and 300C is
0.20%, between 25 and 370C 0.60% is allowed.
Thermal expansion of inlay wax
(paraffin).
A- cooled under Pr
B- cooled without Pr

28. • Knowledge of amount of wax expansion or contraction provides a
basis on which to judge the compensation necessary to produce an
accurate casting.
• Data sufficient to show the thermal contraction of the wax from its
working temp to room temp are included in each package of inlay
wax that complies with ADA Sp No 4
• Specification also requires ,instructions regarding method of
softening and working temp for direct patterns.

29. WAX DISTORTION /WARPAGE OF WAX PATTERN
• Wax distortion is probably the most serious problem during forming
and removal of the pattern from the mouth or the die.
• Distortion results from
-thermal changes
-relaxation of stresses (on cooling)
-occluded air
-molding
-carving
-removal and the time and temp of storage
• Waxes tend to return to their original shape after manipulation,
property is known as elastic memory.
• The casting fits best when the pattern is invested
immediately after its removal from the die.

30. Inlay wax softened over bunsen burner and left in room temp water for several hours
It tends to return to its orignal shape, the inner mol were under compression while
Outer ones under tension.

31. Castings made from patterns with melted wax cooled under pressure
A- Pattern invested immediately
B- Pattern stored for 2 hr
C- Pattern stored for 12 hr

32. • One can minimize the incorporation of residual stress by softening a
wax uniformly by heating at 500C for at least 15 min before use ,
also by using warmed carving instruments and a warmed die, by
adding wax to the die in small amounts.
• Greater warpage results at higher storage temp.
• Inlay wax pattern if allowed to stand longer than 30 min, should be
kept in a refrigerator , the distortion will be less as compared to
room temp.
• During spruing distortion can be reduced by use of solid wax sprue
or hollow metal sprue filled with sticky wax. If the pattern was
stored margins should be re-adapted.

33. • Sprue position- Ideal area for the sprue former is the point of
greatest bulk in the pattern to avoid distorting thin areas and permit
complete flow of the alloy into the mold cavity.
• It should be attached with the pattern on the master die, provided
the pattern can be removed directly in line with its path of
withdrawl from the die.
• Sprue diameter- same size as the thickest area of the wax pattern
,if the pattern is small, the sprue former must also be small.
• Length should be adjusted ,
Gypsum bonded investment – 6 mm of the open end of ring
Phosphate bonded investment – 3 -4mm “ “ “ “

34. MANIPULATION OF INLAY WAX
• Dry heat is preferred to the use of water bath (54-600C)
• For type I (direct technique), it is softened over a flame until it
becomes shiny.
• It is kneaded, shaped and pressed in the prepared cavity.
• Pressure is applied by finger or pt biting on it.
• It is cooled gradually, before taking out.
• For fabricating indirect pattern (type II) die should be lubricated,
preferably with a lubricant, containing a wetting agent.
• Excess must be avoided .
• Melted wax is added in layers with a spatula or waxing instrument
or may be painted on with a brush.
• Wax is then carved to proper contour.
• A silk or fine cloth may be used, for final polishing.

35. • Dipping waxes are kept molten for constant usage .
• Wax pots kept at different temp can be used.
• Proportion of these waxes have not been characterized , nor do
they fall in any present specification.
Wax heating unit
Temp range 30-1100C

36. Modeling instrument set, wax knife
Thomas modeling instrument No 1
Tweezer, wax pencil, rubber adapter
Tooth brush
An electric wax knife with temp
Regulator and transformer, can be
Adjusted to a max of 2500C
Lubrofilm wax surface tension reducing agent, makes
Investing easier

37. CASTING WAXES
• The pattern for metallic framework of RPD and other similar
structures is fabricated from casting waxes.
• They are available in the form of sheets (.3 to .6mm), ready made
shapes and in bulk.
• Ready made shapes are supplied in round, half round and pear
shaped rods & wires of various gages in approx 10 cm length.
• Exact composition is not specified but they include ingredients
similar to inlay waxes with various combination and proportions of
-Paraffin
-Ceresin
-Beeswax
-Resins and other waxes being used

38. • Casting wax sheets are used to establish min thickness in certain
areas of partial denture framework such as palatal and lingual bar
and to produce desired contour of lingual bar.
DENTAURUM (Germany)
Model Casting, Wax Preforms
Available in green (clasps) and red (retentions) colors
Premolar clasps, molar clasps, bonyhard
Clasp, ring clasp
Ring clasp, lingual bars, ridge retensions
Grids ,coarse grids, fine grids.

39. Perforated retentions ,sprue former patterns ,loop
Retensions.
Wax profiles- available as 0.6-5.0 mm dia, semi-circular profiles max and man
Profiles, arches, finishing strip, sprue former strip.

40. Casting wax, Veined, Grained For casting procedure available in different
Thickness , 0.3, 0.35, 0.4, 0.45. 0.5, 0.6 mm.
Fine veined, medium veined, coarse veined
Coarse grained

41. Connecting wax, dark green- Special wax for rapid build up of connections
Between the base and the clasps and retainers, melting point 740C
Thermo wax, pink- high melting point blocking
Out wax for undercuts, melting point 960C

42. PHYSICAL CHARACTERSTICS
• These waxes possess certain degree of tackiness
• This helps to maintain their position on the cast and on each other during
assembly of pattern.
• There is no ADA specification for these casting waxes.
• A federal specification has been formulated No U-W 140(march 1948)
Type of wax flow Breaking point working
properties
Casting wax 350C-max,10% no fracture at Pliable and readily
Class-A-28 gage 380C-min,60 % 23 0C +/- 10 adaptable at 40 to 450C
pink copy accurately surface
Class-B-30 gage against which it is pressed
green shall not be brittle on cooling
Class-C-ready made shape ,blue vaporize at 5000C,leaving no film
other than carbon

43. • The flow characteristic show a max of 10% flow at 35oC and min of
60% flow at 380C.
• This is significantly different from inlay waxes.
• There is little need for casting waxes to exhibit low flow at body
temp.
• Requirement for ductility is high, federal specification requires that it
be bent double upon itself without # at a temp of 230C, and that
they be pliable and readily adaptable at 400C
• Like inlay wax they must vaporize at 5000C with no residue other
than carbon.

44. DIFFERENT COMMERCIALLY AVAILABLE BRANDS
FOR CASTING WAXES
• DENTAURUM (GERMANY)
Supplied by kalabai in our college, 100 gms cost around Rs 540/-
• SHOFU (Kyoto, JAPAN)
• GC Dental industrial Corp (Tokyo, JAPAN)
• JELENKO (USA)
• SCHULER Dental (GERMANY), S-U Dental wax
• DEGUSSA AG (GERMANY), Plastodent
• Kerr Dental Casting Waxes
• Shiva Products MAARC INLAY/Pattern wax, MAARC Casting wax
sheets
http://www.indiamart.com/shivaproducts

45. REVIEW OF LITERATURE
JADA, Vol 90 feb 1975
In year may 1975 the revision of ADA sp no 4 for dental inlay casting
wax was approved by the council on dental materials and devices
of the American dental association.
Major differences from the previous specifications were
1) Inclusion of synthetic waxes
2) Change to three types and classes, of inlay waxes
3) Change in flow requirement.
Revision became effective Jan 1 1976
Scope and classification
1.1 Scope- for inlay casting wax, consists essentially of natural and
synthetic waxes , resins and hydrocarbons of paraffin series.

46. 1.2 –Types and Classes
Type-A Hard
Class1-Sticks
Class2-cones
Class3-other shapes
Type-B Medium
Class1-sticks
Class2-cones
Class3-other shapes
Type-C soft
Class1-sticks
Class2-cones
Class3-other shapes

47. Section 3.7 Outlines for flow requirement
FLOW % WAX TEMP 0C
Min max Type A Type B Type C
--- 1 43 37 34
1 15 46 40 37
50 85 49 43 40
70 90 52 46 43
Revision was done again in 1983 which was reaffirmed in 2003, it was decide
To follow the specifications in second revision, including flow requirements
Which are presently being followed.

48. DISTORTION OF WAX PATTERN CAUSED BY THE FORCES OF
SETTING EXPANSION OF GYPSUM BONDED INVESTMENT
• Mahler and Andy concluded that hygroscopic expansion of
gypsum products was an extension of normal crystal growth caused
by the addition of water, rather than true hygroscopic expansion
resulting from water molecules forcing particles apart.
• Shell and Hollenback found that vertical and horizontal expansion
varied in proportion to the length of asbestos liner, they found that
castings made with full length liner were longer than the wax
pattern by 0.4% and castings made with liner 3mm short of both
ends of the liners were shorter than the wax pattern by approx
0.6%.

49. • Exploring the effects of different investments on marginal fit of
inlays and crowns ,Jenkins & Phillips found significant differences
in the marginal gaps of inlays depending on which investment was
used ,but noted no overall significant differences.
Complete crowns exhibited no significant
differences in marginal discrepancies regardless of the investment
or technique.
• D.R.Davis in 1997 conducted a study to determine whether the
magnitude and characteristics of distortion could be modified by
limiting the vertical setting expansion.
Wax patterns were formed on standard dies of MOD inlays and
complete crowns, Invested in conventional open ring and modified
closed ring using same investment and technique.
after casting thickness of the cement film
was measured at specific sites.
The complete crown group exhibited less distortion than MOD inlay
group.

50. • Eleini Kotsiomiti and Athanasios.K
In the year 1994 conducted a study to see the behavior of crown
pattern waxes on heating and cooling, Flow and Linear thermal
expansion were determined and compared with those reported by
previous investigators.
They concluded,
1) Increase in flow of the pattern waxes caused by in increase in
temp occurs in the range of 37-470C for the majority of the
material tested.
2) Most of the material flow by 61% to 82% at 470C to 520C .This %
seems to be adequate for easy handling. The temp increase
provokes a linear expansion of more than 1% for most pattern
waxes.
3) Rate of expansion varies during an increase in temp, the changes
that occur at transition points are related to structural changes in
the material.
4) Similarity of arrest points in the material tested is indicative of
similar compositions and proportions of the major constituents.

51. • Michio Ito et al in 1996 conducted a study to evaluate the
relationship between flow characteristic, bonding strength and
softening temp of paraffin and dental inlay waxes to casting
shrinkage when patterns were invested with a phosphate bonded
investment.
They concluded
1) Casting shrinkage decreased when flow of wax pattern increased
.
2) The flow of wax pattern increased as the exothermic reaction
increased
3) A larger casting ring is suggested for casting when a relatively
thick wax pattern or an inlay wax that has a high strength,
softening temp and low flow % is used.
4) Some industrial waxes demonstrated potential for dental casting
but research is needed.

52. • Randa Diwan et al in 1997 conducted a study to see
inaccuracies of pattern waxes in fixed and removable partial
denture castings
they conclude that wax is not the only potential cause of
inaccuracies other factors are:-
1) Clinical and technical errors caused by dentist and dental
technician
2) Lab errors – improper manipulation of other dental materials eg
duplicating procedure of master cast, refractory investment
3) Liquid-powder ratio for both stone and investment mixes
4) Spruing ,improper burnout, overheating or underheating the
metal, erratic finishing and polishing.

53. ALTERNATIVE TO PATTERN WAXES
• Pattern waxes are being replaced to some extend by preformed
plastic pattern.they are completely combustible.
• Plstic retentions
Plastic retensions
Preformed plastic pattern in different
Shapes and sizes

54. Pattern resins
• Available in both
Autopolymerizing acrylic resin (Duralay)
Light curing resins (Modilux)
• Pattern resins are characterized by higher strength and
resistance to flow than waxes, good dimensional stability
and burn out without residue.
• Full crown patterns fabricated from pattern resins and inlay
waxes have shown similar marginal discrepancies.
• A pattern is fabricated by applying the resin in in 3-5 mm
layers and curing in a light chamber or with a hand held
light curing unit
• Resin is completely eliminated from the mold before casting
by heating at 6900C for 45 min.

55. • Cahi E, Rosen M, Becker PJ in 1996 did a comparison of the
dimensional stability of three inlay patterns
- Kerr’s Type II blue inlay casting wax
- Modilux (light curing resin)
- Duralay (autopolymerizing acrylic resin)
They concluded that
- Wax underwent more contraction than Duralay and
Modilux
- More contraction occurred at 24 hr than between onset
and one hr.
- As contraction occurred after one hr and the wax
contracted the most , it was recommended that Duralay and
Modilux be used as pattern material, especially if delay in investing
is anticipated.

56. • M.Krane et al in 1998 conducted a study on the surface of resins
that burn without residues in the lost wax procedure.
A total 480 specimen from 16 different manufactures were examined
They concluded that surface structure of the residue from resins
examined were in a range acceptable for the dental casting
technique.
An increased application of residue free resins in dental
casting technique is therefore recommendable. These resins could
not only complement waxes or wax/resin composition, but could
even ,in whole or in part replace them.

57. CONCLUSION
• Waxes have been popular and useful dental material.
• Easily manipulated
• Low in cost and serve variety of purposes
• Nevertheless use of dental waxes is associated with control of
certain characteristics that affect their applicability, such as
-Effect of heating on flow
-Thermal expansion
-Distortion
• Way back in 1939 Hollenback et al published the results of their
extensive work on properties of waxes.
They concluded that waxes are sufficiently
stable material if handled properly.

58. • REFERENCES
 Kenneth j. Anusavice ; Phillips Science of dental material .Eleventh edition,
Elsevier,2004.
 Jack L. Ferracane ; Materials in Dentistry principles and application. Second edition
,Lippincot williams, 1995.
 William J. O’Brien; Dental materials and their selection. Third edition, quintessence
Publishing co. 2002.
 Robert C. Craig John M. Powers, John C.Wataha ;Dental materials properties and
manipulation,. Eight edition,2004.
 Marcia gladwin; clinical aspects of dental materials Lippincott Williams 2000
 E.C.Combe; Notes on dental materials, sixth edition Churchill livingstone 1992
 Revised ADA specification No 4 for dental casting wax,JADA Vol 90 Feb 1975
 Davis.D.R, 1987, “Limiting wax pattern distortion caused by setting expansion”.JPD
Aug 58(1):229-32
 Kotsiomiti E. Kaloyannides A,1994, “Crown pattern waxes: A study of their behavior
on heating and cooling “JPD May 71: 511-6
 Ito M et al,1996, “Effect of selected physical properties of waxes on investments and
casting shrinkage”JPD Feb 75: 211-6
 Diwan R et al,1997, “pattern waxes and inaccuracies in fixed and removable partial
denture castings” JPD May 77:553-5
 Krane M et al 1998, “study on the surface of resins that burn out without residues
lost-wax procedure”,JPD, 79:389-92
 Waxes crown and bridge casting procedures, DENTAURUM

59. Thank you