2. Contents
• Introduction
• Components of dental waxes
• Properties of waxes
• Classification of waxes
-According to origion
-According to use and application
• Conclusion
• References
3. Introduction
• 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.
4. • 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.
8. Components of dental waxes
Natural
waxes
Synthetic
waxes
Additives
•Mineral
•Plant
•Insect
•Animal
•Acrawax C
•Aerosol OT
•Castorwax
•Aldo 33
•Stearic acid
•Oils
•Colorants
•Resins
9. Natural waxes
Complex combination of organic
compounds of high molecular weights.
It’s the primary components of dental wax.
The dental manufacturers must blend the
particular batches of waxes to obtain the
properties desired for a particular
application.
12. Fats
• Increase the melting range and the
hardness of compound waxes.
• Hydrocarbon oils - soften mixture of
waxes.
• Silicone oils - improve the ease of
polishing with waxes.
13. Resins
• Most natural resins are obtained from
trees and plants.
• Insoluble in water
• improve toughness, hardness,
melting range of waxes
15. Melting range
• Waxes consist of similar type of
molecules of different molecular
weight.
• They may contain several types of
molecules
• They have melting range rather than
melting point.
16.
17. Thermal expansion
• Expand when temperature is risen
• Contract when temperature is decreased
• Dental waxes have the largest
coefficient of thermal expansion.
• Temp. change in wax patterns may be
a major contributing factor in inaccuracy
of the finished restoration.
18.
19. Mechanical properties
• The elastic modulus, proportional limit
and compressive strength of waxes
are low compare with those of other
materials and these properties depend
strongly on the temperature.
20.
21. Flow
• Flow is decidedly dependent on the
temperature of the waxes.
• Flow is greatly increase as the melting
point of the wax is approached.
24. Ductility
• Ductility increase as the temp of a wax
is increase.
• Waxes with lower melting temp. have
a greater ductility.
• The ductility of a blended waxes
wide melting range > narrow melting
range
• The highly refined waxes is quite brittle
26. ACCORDING TO ORIGIN
Natural Synthetic
Mineral
Paraffin, microcrystalline, ceresin Polyethylene waxes
Montan, Polyoxyethylene glycol
waxes
Plant
Carnauba, candelilla
Insect
Beeswax
Animal
Spermaceti wax
27. • Pattern waxes
• Processing waxes
• Impression waxes
According to use and application
28. Pattern wax
• Used to form the general
predetermined size and contour of
artificial dental restoration , which is
to be constructed of a more durable
material.
30. Processing wax
• Used primarily as auxillary aids in
the construction a variety of
restorations and appliances either
clinically or in the laboratory
35. • A pattern of the wax is first constructed
that duplicates the shape and contour of
the desired casting .
Inlay pattern wax
36. • The pattern then is embedded in a
gypsum-silica investment material to
form a mold with an ingate or sprue
leading from the outer surface of the
investment mold to the pattern.
Inlay pattern wax
37. • The wax is subsequently eliminated by
heating & softening and the mold is
further conditioned to receive the
molten metal.
Inlay pattern wax
40. Inlay waxes generally are
produced in deep blue, green, or
purple rods or sticks.
The flow can be reduced by adding
more carnauba wax or by selecting
higher melting paraffin waxes.
41. Inlay waxes : Properties
ANSI/ADA Specification No. 4 for
dental inlay casting wax.
Type I wax = a hard wax that is
prescribed for forming direct patterns in
the mouth.
Type II wax = a softer wax that is used
as an indirect technique wax.
43. Flow
The working temperature for making
direct wax pattern must not to be so high
as to cause damage to the vital tooth
structure.
At mouth temp., direct inlay wax must
have essentially no flow to minimize the
possibility of distortion of the pattern
during removal from the tooth cavity.
44. Casting wax
The pattern for the metallic framework of
removable partial denture and other
similar structures is fabricated from the
casting waxes.
45.
46. Casting wax : Composition
The ingredients are similar to
those found in inlay waxes.
47. Casting wax : Properties
Federal specification No U-W -140 for
casting wax
Flow : 35
o
C - maximum, 10 %
38
o
C - minimum, 60 %
Breaking point : no fracture at 23
o
+1
o
48. Pliable and readily adaptable at
40o
to 45o
C
Copy accurately surface against
which it pressed
Shall not be brittle on cooling
Vaporize at 500o
C, leaving no
film other than carbon
Working properties
49. Baseplate wax
Baseplate wax derives its name
from its use on the baseplate tray
in the technique for complete
denture restoration.
54. serves as the material to produce the
desired contour of the denture after the
teeth are set in position
Baseplate wax
55. Baseplate wax : Composition
70-80 % paraffin or ceresin
small quantities of other waxes &
additives.
typical composition
– 80% ceresin - 12% beeswax
– 2.5% carnuaba
– 3% natural or synthetic resins
– 2.5% microcrystalline or synthetic wax
56. Baseplate wax : Properties
ANSI/ADA Specification No.24
– Type I - Soft, building contours and
veneers
– Type II - Medium, patterns in mouth,
temperate
– Type III - Hard, patterns in mouth,
hot weather
57. Linear thermal expansion from 25
o
-40
o
C <
0.8%
Softened sheets shall cohere readily
without becoming flaky or adhering to
fingers
No irritation of oral tissue
trim easily with a sharp instrument at 23
o
C
Practical requirements
58. Smooth surface after gentle flaming
No residue on porcelain or plastic teeth
Coloring shall not separate or
impregnate plaster during processing
No adhesion to other sheets of wax or
separating paper on storage
Practical requirements
59. Boxing wax
Use to form a plaster or stone cast from
an impression of the edentulous arch
60. Boxing wax: Working properties
Federal specification No U-W -138
Smooth, glossy surface on flaming
Pliable at 21
o
C, retain shape at 35
o
C
Seals easily to plaster with hot spatula
61. Utility wax
Used in numerous instance
most likely consists of beeswax,
petrolatum and other soft waxes
62. Utility wax: Working properties
Federal Specification No U-W- 156
Pliable at 21
o
to 24
o
C
Tacky at 21
o
to 24
o
C, sufficient adhesion
to build up
63. Sticky wax
It is sticky when melt and adheres closely
to the surface on which it is applied.
It is firm, free from tackiness and brittle
at room temp.
Rosin & yellow beeswax are the usual
major constituents.
64. Sticky wax : Working properties
Federal Specification No.U-W-00149a
Sticky when melt
Adhere closely
Not more than 0.2% residue on burnout
Not more than 0.5% shrinkage from
43
o
to 28 C
o
65. Blockout wax:- is used to fill voids and
undercuts for R.P.D
white wax :- for making patterns to
stimulate a veneer facing.
66. Corrective impression wax
Used as a wax veneer over an original
impression to contact and register the
detail of the soft tissue .
Formulated from hydrocarbon waxes
such as paraffin,ceresin & beeswax and
may contain metal particles
The flow at 37
o
C is 100 %
68. Bite registration wax
Used to accurately articulate
certain models of opposing
quadrant
Formulated from beeswax or
hydrocarbon waxes such as
paraffin or ceresin and contain
alumina or copper particle
71. 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.
72. • 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.
73. 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.)
74. 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.
75. 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
temperature.
• Used to modify the properties of paraffin wax
(also the main component of sticky wax)
76. Natural resin (gum dammer)
• 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.
77. 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.
78. 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.
79. Other polymers in dentistry
Gutta-percha
Filling material
:composite resin
Dental cement
80. Gutta-percha
A polyisoprene with the same empirical
formular as rubber (20-30%)
various natural resin
(soften the gutta-percha)
filler : ZnO,waxes
Composition
82. • Used to fill in the root canal
• Soften at 60-70
o
C
• Viscoelastic material which is extremely
sensitive to the rate of straining.
• The best adaptation to the root canal is
achieve when maximum pressure is
applied over an extended period of time.
Gutta-percha
83. 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.
84. • 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
