dental waxes have a vivid role in dentistry. dental waxes are a combination of waxes to achieve desired properties.

1. Dental waxes
SRI GURU RAM DAS INSTITUTE OF
DENTAL SCIENCES
Lecture by:
Dr. Neelam Suman

2. Waxes have a vivid role in dentistry. Many
procedures in dentistry require the use of waxes .
The inescapable applications of waxes in
dentistry stem from waxes’ special combination of
properties. Waxes are used for some of the
highest precision work as well as cruder tasks. In
the processing of dentistry, waxes are very
important for dentists and technicians.
INTRODUCTION

3. Wax- one of several esters of fatty acids with
higher alcohols, usually monosacharides alcohols.
Dental waxes are combinations of various types
of waxes compounded to provide desired
physical properties.
GPT-8th edition
DEFINITION

4. CLASSIFICATIONS
Waxes are being classified as-
On the basis of production.
On the basis of uses.

5. ON THE BASIS OF PRODUCTION
a. Naturals waxes-
• Mineral
• Plants
• Insect
• Animal
b. Synthetic waxes-eg. Polyethylene waxes.
c. Gums- eg. Gum arabic.
d. Fats- eg. Glyceryl tristearate
e. Resins-
i. Natural resins- eg. Dammar.
ii. Synthetic resin-eg. Vinyl resins.

6. ON THE BASIS OF USE
Pattern Processing Impression
Inlay
Type-1
Type-2
Boxing
Utility
Sticky
Solder
Corrective
Bite
Casting
Sheet
Ready shapes
Wax-up
Relief wax
Base plate

7. The chief constituents of most mineral waxes are
hydrocarbons ranging from 17 to more than 44 carbon
atoms. Some waxes contain free alcohols and acids as
well.
The hydrocarbons in plant waxes are saturated alkanes
with 19 to 31 carbon atoms .
Therefore, dental waxes contains molecules having a
range of molecular weights that affect the melting and
flow properties of the wax.

8. The composition of natural waxes indicates that
they are complex combinations of organic
compounds of reasonably high molecular
weights.
The composition of these waxes varies,
depending on the source and the time of
collection also.

9. COMPONENTS OF DENTAL WAXES
Natural waxes Synthetic waxes Additives
Mineral-
paraffin
microcrystalline
barndahl
ozokerite
ceresin
montan
Acrawax
Aerosol OT
Castorwax
Stearic acid
Glyceryl
tristearate
Oils
Turpentine
Plant
carnauba
candelilla
japan wax
cocoa butter
Insect-beeswax
Animal-spermaceti

10. CHARACTERISTIC PROPERTIES OF
WAXES
THE ANSI-ADA SPECIFICATION NO. 4
GOVERNS THESE PROPERTIES

11. MELTING RANGE
Because waxes are mixtures of different components,
they do not melt at a single temperature and do not
have a melting point.
Rather, waxes have a melting range.
The melting range for
paraffin wax - 44° to 62°C, and
carnauba wax- 50° to 90°C.

12. At the low end of the range, some but not all of
the components melt, which causes the wax, still
solid, to flow much more.
As the temperature increases through the melting
range, more of the components melt, and the
wax flows severely and eventually all components
become a liquid.
Clinical implication

13. EXCESS RESIDUE
As wax patterns used in the lost-wax technique
are melted or burnout to remove them from the
casting mold, the wax must not leave a residue,
which would affect the quality of the final
restoration.

14. FLOW
Flow is a change in shape or dimension in response to
an applied force.
Below, the melting point of the wax, however, a measure of
the flow actually would be a measure of the degree of
plastic deformation of the material at a given temperature.
It is caused by the slippage of the long-chained wax molecules over
each other.
At low temp. waxes hardly flow at all, but as temperature.
reaches melting point flow increases dramatically.

15. FLOW DEPENDS ON
The temperature of the wax.
The force bringing about the deformation.
The time the force is applied.

16.  Yellow beeswax does not flow extensively until it reaches
38°C, and at 40°C it flows about 7%.
 Therefore, it is used as a main ingredient in dental
impression waxes.
 For pattern waxes, flow is generally not desirable at room
or mouth temperature, because it results in a permanent
distortion of the wax pattern.
 For processing waxes, flow is a highly desirable property
because these waxes need to be pliable at room
temperature.
Clinical implication

17. THERMAL
EXPANSION
When waxes are heated, they expand
significantly and contract with the decrease
in temperature.
It usually is reported as parts per million of
expansion per Celsius degree of the rise in
temperature of the specimen.
This number is called the “coefficient of
thermal expansion of the wax”.

19. The linear thermal expansion properties of waxes
may be explained on the basis of the strength of
secondary valence forces and the transition
points.
Mineral waxes expand more because they have
weak secondary valence forces, which are easily
overcome by the energy absorbed during a rise in
temperature.

20. MECHANISM
Many waxes exhibit at least two rates of expansion between
22° and 52°C.
These changes in rate of expansion occur at transition points.
During the transition phase, hydrocarbon chains of a mineral
wax become free to rotate; consequently, after a wax has
been heated through a transition point, it is free to expand.
Because the ingredient waxes are undergoing transitions that
do not coincide with one another, certain inlay waxes exhibit
more than two changes in rate of expansion.

21. CLINICAL IMPLICATION
Waxes have the highest coefficients of thermal
expansion of any dental materials.
Eg. Pattern wax is 323×10-6/°C, but that of dental
ceramic is 20 times less at about 14×10-6/°C.
For pattern waxes, thermal expansion is critical.

22. RESIDUAL STRESS
It is the stress remaining in a wax as a result of
manipulation during heating, cooling, bending,
carving, or other manipulation.
Manipulation of wax puts molecules of the
wax into positions that they do not like but
cannot change because of their solid state.

23. MECHANISM
When the specimen is held under compression
during cooling,
the atoms and molecules are forced closer together
than when they are under no external stress.
After the specimen is cooled to room
temperature and the load removed,
the motion of the molecules is restricted;
this restriction results in residual stress.

24. specimen is heated,
the release of the residual stress is added to the normal
thermal expansion, and the total expansion is greater
than normal.
When the specimen is cooled while under tensile stress
and expansion as a result of heating is measured,
the release of the residual tensile stress results in a
dimensional change that is opposite to the thermal
expansion.

25. These stresses that are present in wax generally are
released as the temperature of the wax increase and the
wax molecules can move more freely.
But at the same time, it may cause an irreversible
deformation that can destroy the fit of a wax pattern.

26. TYPES OF DENTAL WAXES
PATTERN WAXES
• Used to form general pre determined size & contour of an
artificial restoration.
• Later it is replaced by more durable material such as
cast gold, cobalt- chrome- nickel alloys etc.
• They exhibit thermal change in dimension and
warpage on standing.

27. INLAY WAXES
• Inlays, crowns & bridge units are
formed by a casting process that uses
lost wax pattern technique.
• A pattern of wax is constructed that duplicates
shape and contour of casting.
• After investing & spruing the wax is
eliminated by heating.

28. Paraffin- 40-60% - Determines the melting point.
-Flakes when trimmed.
-Does not gives smooth surface
Carnauba - 25% - Increases hardness.
-Decreases flow at mouth temperature.
Ceresin - 10% - Reduces flakiness
Bees wax - 5%
Gum Dammar Increases finish and gives smooth surface.
Increases resistance to cracking and flaking
Synthetic waxes Improve working charactericstics.
COMPOSITION

29. Types
By flow:
1. Hard
2. Regular
3. Soft
Flow can be reduced by
• Adding more carnauba wax.
• Using higher melting paraffin wax.

30. By technique:(Revised ANSI/ ADA Sp. No. – 4)
Type I - Direct. -Hard wax used for forming patterns
directly in mouth.
Type II – Indirect. - Softer wax used for indirect
technique

31. TYPE I
• Lower flow at 37°C to minimize any distortion on
removal from mouth.
• Working temperature for registering cavity details
is around 45°C.
• Should not be high, so as to avoid damage to pulp.
• Maximum linear thermal expansion allowed –
25°C – 30°C – 0.20%
25°C – 37°C – 0.60%

32. Manipulation:
• Prepared cavity is recorded directly.
• Wax is softened over an open flame. Should be
rotated for uniform heating.
• Placed into cavity under finger pressure.
• Allowed to cool gradually.
• Pattern to be handled minimum.

33. Insufficient flow of wax caused by
insufficient heating causes:
• Lack of details.
• Excess stress within the pattern.
• Excess flow by over heating makes compression
of wax difficult. (Because of lack of body)
• From mouth temperature to room temperature
(24°C) there is 0.4 % linear contraction.

34. TYPE II
Softer wax used for Indirect technique or Pulled pattern
technique.
These waxes are commercially available
for crown & bridge work and inlays in the form of
• Sculpturing / Modeling waxes.
• Dipping waxes.

35. These are usually produced in-deep
blue, green or purple rods or sticks
about 7.5 cm long and 0.64 cm in
diameter.
They are also supplied in small pellets,
cones or in metal ointment jars.

36. USES
Used in the fabrication of fixed partial denture
framework.
Used in the fabrication of cast partial denture
framework.

37. PROPERTIES
 These waxes have shown nonvolatile residue to a
maximum of 0.10% at an ignition temperature of 700°C.
 Flow- the working temperature, should not be so high as to
cause damage to the vital tooth structure & should
sufficiently flow into the prepared cavity.
 Thermal coefficient of expansion- a decrease of 12°C to
13°C in temperature, from mouth temperature to a room
temperature of about 24°C, causes a 0.4% linear
contraction of the wax, or about 0.04% change for each
degree change in temperature.

38. WARPAGE OF WAXPATTERNS
Inlay wax has a high coefficient of expansion and tends
to warp or distort when allowed to stand unrestrained.
The distortion is increased generally as the temperature
and time of storage are increased.

39. PREVENTION OF
WARPAGE
 The higher the temperature of wax at time pattern was adapted
&shaped, the less the tendency for distortion in the prepared
pattern.
Reason- the residual stress causing distortion is associated
with force necessary to shape wax originally.
 incorporation of residual stress can be minimized
-softening wax uniformly by heating at 50°C for
at least 15 min before use,
- by warm carving instruments and a warmed die,
and
- by adding wax to the die in small amounts

40.  Lower temperature does not completely prevent distortion, but
generally the amount is reduced when the
-storage temperature is kept to a minimum.
- if pattern allowed to stand uninvested for time
longer than 30 min, they should be kept in refrigerator.
- A refrigerated pattern should be warmed before investment.
 During spruing, distortion can be reduced by use of a solid wax
sprue or a hollow metal sprue filed with sticky wax.
If pattern was stored, margins should be readapted.
The best way to minimize the warpage of inlay wax patterns is to
invest the pattern immediately after it is completely shaped.

41. CASTING WAX
• Used for metallic framework of
RPDs.
• Available as sheets (28 – 30 gauge; 0.4 – 0.32 mm),
Readymade shapes-
- Round:10cm,
half round, and half pear shaped rods.
-Reticular, grid, or mesh form.
-Clasp forms and other forms

42. Composition:
• Paraffin wax
• Ceresin
• Bees wax
• Resins
• Other waxes

43. Classification:
(according to FDI specification No:140)
1. Class A
28 gauge-Pink
• Flow of about 10% at 35 degree Celsius.
• Easily adaptable at 40-45 degree Celsius.
2. Class B
30gauge- Green
• Minimum flow of 60% at 38 degree Celsius.
• Adapts well to surface.

44. 3. Class C
Readymade shapes- Blue
• Will burnout at 500 degree Celsius, leaving no carbon residue.
Casting wax serve same purpose as inlay wax,
differ slightly in physical properties.
• Ingredients similar to inlay waxes.
• Sheets used to establish minimum thickness
in some areas of RPD framework such as
palatal & lingual bar.

45. BASEPLATE WAX
ADA 24
• The basic use is to form occlusal rim on baseplate
tray to set teeth for denture.
• Establish Vertical dimensions, contour of the denture
after teeth setting.
• Also used for MFPs,
• patterns for orthodontic appliances and other prosthesis
that are to be processed in acrylic resin
• Checking articulating relations in mouth &
transferring to articulators.

46. Composition:
Paraffin or Ceresin-80%
Bees wax-12%
Carnauba-2.5%
Natural or synthetic resin-3%
Microcrystalline wax-2.5%
Coloring agents

47. • Supplied as sheets
• 7.60 x 15 x 0.13 cm, red, pink or
orange in colour.
•
•Three types:
Type I – soft wax for contours & veneers.
Type II – medium wax for temperate climates.
Type III – hard wax for tropical climates.
Mainly differ in flow, with type III having least.

48. Requirements
• Linear thermal expansion from 25° to 40°C < 0.8%
• Softened sheets shall cohere readily without becoming
flaky or adhering to fingers.
• No irritation to oral tissues.
• Pigment not to separate on processing.

49. PROCESSING WAXES
Used mainly as accessory aids in the construction of a variety
of restorations and applications, either clinically or in
laboratory.
• Boxing wax
• Beading wax
• Sticky wax
• Utility wax

50. Boxing Wax and Beading wax
• Aids in forming a plaster or stone
cast from an impression.
• Boxing consists of adapting a long narrow strip of
wax around the impression below peripheral height,
followed by a wide strip of wax to form a wax box.
• Available in Green or Black colors.
• Also called carding wax; originally used for
placing porcelain teeth in packing.

51. Federal requirements (U-W- 138)
• Smooth glossy surface on flaming.
Pliable at 21°C; retains shape at 35°C.
Readily adapt to impression at room temperature.
• Seal easily to plaster with hot spatula.
Supplied as:
Boxing wax as sheets, beading wax as strips.
They are pliable and can be adapted easily. A slight
tackyness allows it to stick to the impression.

52. UTILITY WAX:
Composition:
Consists mainly of beeswax,
petrolatum, and
other soft waxes in varying proportions.
Supplied as:
It is available in the form of sticks and sheets.
Use
adjust contour of perforated tray for use with
hydrocolloids,
It is pliable and can be easily moulded. It is adhesive and
can stick to the tray.

53. STICKY WAX:
Composition
mainly yellow beeswax,
rosin, and
natural resins such as gum dammar.
It is sticky when melted and adheres closely to the
surfaces upon which it is applied.
At room temperature, it is firm, free from
tackiness, & brittle.
Uses:
Used for joining metal parts before soldering &
for joining fragments of broken dentures before
repair procedure

54. Impression waxes, though rarely used to record complete
impressions, they can be effectively used to correct small
imperfections in other impressions.
They are thermoplastic materials, which flow readily at mouth
temperature and are relatively soft even at room temperature
Impression waxes are classified as:
1) Corrective impression wax
2) 2) Bite registration wax.
There are no ADA federal specifications for impression waxes.
IMPRESSION WAXES

55. consist typically of a mixture of low melting paraffin wax
and bees wax (about 3:1)
COMPOSITION

56. Uses:
 It is used as a wax veneer over an original
impression to contact and register the details of the soft
tissues.
 To make functional impression of free end saddles
(Class I and II removable partial dentures).
 To record posterior palatal seal in dentures
 Functional impression for obturators
CORRECTIVE IMPRESSION WAX

57. A simple formula for producing corrective impression
wax from paraffin wax and bees wax is described by Mc
Crorie i.e. mixture of yellow bees wax and paraffin wax
with flow characteristics at 37ºC
Wax Mixture (% flow at 37ºC)
75% yellow bees wax: 25% parafiin wax (80)
50% yellow bees wax: 50% paraffin wax (85)
25% yellow bees wax: 75% paraffin wax (89)
CORRECTIVE IMPRESSION WAX

58. Extra hard No.1 (pink): A reinforcing material
used only on external surface to support -wax
extensions beyond tray margins. -
Hard No. 2 (yellow): rebasing as a hard
foundation for Korrecta waxes 3 and 4 when
extensive alveolar resorption necessitates a bulk
of material.
restore occlusion in a partial denture or a
removable partial denture, which has settled due
to severe tissue change.
Soft No. 3 (red): Used for minor tray correction
& as an initial lining to stabilize tray.
Extra soft No. 4 (orange): Used to secure a
completely adapted impression under natural
masticatory pressure. It leaves a finished surface
and registers fine tissue details.
KORRECTA WAX
%flow at 37ºC
 3%
 80%
 87%
 90%
available in 4 grades, (with a different degree of plastic
deformation at mouth temperature.)

59. Uses:
It is used to articulate accurately the models of opposing
quadrants.
Supplied as: U-shaped rods.
Composed of: Beeswax , paraffin , ceresin.
Procedure:
The wax is placed between the teeth and patient is asked
to bite. It is then taken out and the casts of the patient is placed
in the indentations formed by the teeth. It is then articulated.
BITE REGISTRATION WAX:

60. CONCLUSION:
Wax was probably the first impression material used in dentistry.
It is economic, clean, and easy to use. Waxes are the dental
materials that show high degree of verstality both in properties
and uses. For some tasks they are indespensable and for some a
refinement substitute. Various forms in which they are available
adds attractivness to work. So they can be regarded as boon to
dental work.

61.  McCrorie JW: Corrective impression waxes, BrDent J 1982;152: 95-9.
 Powers JM, Craig RG: Thermal analysis of dental impression waxes, J Dent
Res 1978;57: 37-9.
 Phillips RW. Skinner's science of dental materials,ed 8, P 198-
211.Philadelphia.Saunders.
 Anusavice KJ.Phillip’s science of dental materials ed 11. P283-92. Elsevier.
 Powers JM, Craig RG.Restorative dental materials. ed12. P 337-59. Elsevier.
REFERENCES

62. REFERENCES
 Mc Millan MC, Darwell BC, Rheology Of Dental Waxes. Dent
Mater2000;16: 337-51.
 Ito M, Munoz CA. Effect Of Selected Physical Properties Of
Waxes On Investments And Casting.Shrinkage. J Prosthet
Dent.1996;75:211-6.