3. �Baseplate wax: sheets, establish initial arch
form in construction of CD.
�Bite wax: record the occlusal surfaces of teeth.
�Boxing wax: sheet wax used as a border of an
impression to provide base of the cast to be
made.
�Inlay wax: applied to dies to form direct or
indirect patterns for the lost-wax tech.
�Sticky wax: adheres to dry clean surfaces.
3
Types of waxes
6. ⚫ BASE Wax: that is almost always paraffin (not
smooth, not glossy, flake when trimmed)
(1) Hydrocarbon of paraffin or esters
(2) High or low MW
⚫ MODIFIER Waxes: contribute properties such as
increased hardness, stickiness, or brittleness
(1) Hydrocarbon or ester types;
(2) High or low MW
⚫ COLORANT: 1%
⚫ Fillers: some waxes contain it to control
expansion and shrinkage of the wax product.
6
General Composition
7. Natural (mineral, vegetable, or animal origin and/or
synthetic waxes (more homogeneous & pure)
Natural waxes are complex combinations of organic
compounds of high molecular weight:
⚫ Hydrocarbons,e.g. saturated alkanes, & microcrystalline
wax series, carnauba wax, candelilla wax.
⚫ Esters, e.g.myricylpalmitate.
Some waxes also contain free alcohol and acid.
(Esters are formed from union of higher fatty acids with
higher aliphatic alcohol with elimination of water)
Alcohol+Fatty Acid 🡪Ester+Water 7
Chemical composition
9. ⚫Gum dammar: smoothness, resistant to
flaking, toughness. (resin)
⚫Ceresin the hardness and water resistance
of wax. Improves carving properties.
⚫Carnuba the hardness and water resistance,
melting range, gives glossiness, flow at
mouth temp.
⚫Beeswax the stickiness, improves flow
properties at mouth temperature. (esters)
⚫Rosin the brittleness. (resin)
⚫Microcrystalline waxes stress release on
cooling.
9
Common Modifier Waxes
11. ⚫Occurs because of the Multiple wax mixtures
⚫The liquidus line (representing the temperature at
which complete melting has occurred)
⚫The solidus line (below which the composition is
entirely solid)
⚫the solid + liquid range in between is quite broad
(almost 40°C). To allow manipulation
⚫To develop wax flow, the temperature only needs
to be heated to a point within the solid+liquid
range or up to the point of the liquidus line but
not much higher.
⚫Excessive heating would cause decomposition.
11
Melting range
14. Methods:
1. Flame heated instruments
2. warmth of hand??
3. dry heat as wax pot
4. Water bath, but not for inlay wax??
Flow :
⚫ after the highest melting point is reached.
⚫ Temperature α 1/ viscosity
⚫ Flow temperature must be > mouth temp if needed in
solid state
Over heating should be avoided?
the base or modifier waxes can be decomposed.
14
Heating issues
15. ⚫In solids its analogous to creep
⚫In liquids its analogous to viscosity
⚫Waxes are usually non-flowable at room temperature
⚫Temperature α 1/ viscosity
⚫It is critical for inlay wax to have flow less than 1%
15
Flow
16. ⚫ It is low
⚫ Wax should be softened evenly by
⚫ rotation above the flame until it evenly softens or
flows
⚫ Tempered in a water bath alternately with the
flame heating to allow the core to soften before
dripping
⚫ If a soft core of a bulk of wax is to be made, roll the
wax when it is in softened status – (unable to hold
shape by itself)
16
Thermal conductivity
17. ⚫Used with cast metal techniques
⚫Wax patterns need to be burned to the
point where no excess residue may
interfere with metal casting
⚫Heat melt and/or decompose wax by the
process of oxidation which completely
transform it into water vapor and carbon
dioxide so that no residue is left.
17
Lost wax technique
18. 18
Tackiness or stickiness
⚫ Created by the bees wax addition
in the mixture
⚫ Increased if material is warmed
by hand
⚫ Solid waxes become tacky to
other material if heated
⚫ Adhesives may be applied on
casts before wax application
⚫ Wax dipping in bees wax increase
stickiness of refractory casts
⚫ Old wax adheres to new one if
surface is dry
19. 19
Dimensional stability
⚫Wax should be dimensionally stable
once it has solidified (less than 1%).
⚫ Invest the pattern immediately after
removal from the die.
Deformations:
⚫Plastic deformation
⚫ Under force is by ductility.
⚫ Ductility allows it to be carved
or burnished
⚫Residual stress recovery
⚫Elastic Recovery
20. ⚫Residual stress reduction
⚫ Heat material evenly
⚫ Follow manufacturer instructions
⚫ Invest within 30 min of carving
⚫ Whenever wax additions are cooled. The
exterior surface tends to cool first. The molten
interior slowly solidifies and contracts. This
encourages distortion or flow. Add in small
increments, layering
⚫ Store at low temperatures
20
Residual stress
21. 21
Coefficient of thermal
expansion
⚫Very high
⚫ ceramics (1-15 ppm/°C)
⚫ metals (10-30 ppm/°C)
⚫ waxes (30-600 ppm/°C)
⚫ inlay wax (250-300 ppm/°C)
( wax pattern made in the mouth
will shrink appreciably)
⚫Residual thermal stresses may change
dimensions
⚫Paraffin > beeswax >carnuba
Ñ Do not
heat
above
melting
point
during
work
23. ⚫Wax is hydrophobic
⚫To increase its wetting a surfactant could be sprayed
over wax to increase flow of investment material
23
Surface tension
24. ⚫Coloring is not standardized
⚫Dark colors provide good color contrast for
processing wax
⚫Opaque and Tooth-colored waxes provide good
material for esthetic case presentations and patient
education
24
Color
28. Uses
⚫metal castings of
⚫ Inlays
⚫ Attachments
⚫ Crowns
⚫ Pontics
⚫ Partial dentures
⚫ Denture base material
28
Pattern waxes
29. Forms
sticks pallets, tins
�Blue or green
Consistencies
�Hard, medium, soft, regular
Application
�indirect and direct technique
29
Inlay wax
Removable
Die with
Waxed Inlay
32. Application
⮚Used for metal framework
⮚complete and partial dentures
Forms
Sheets and preformed shapes
Properties
⮚low thermal dimensional change
⮚must have clean excess residue
32
Casting waxes
35. Form
sheets
Types I, II & III
Application
�wax registration of ridge form
�Carved into tissue forms and Support teeth
�Bite registration
Properties
�melting range higher than mouth temperature
�Customised to climate
35
Base Plate wax
38. Wax Bite Registration
Uses
⚫To articulate models
correctly
Forms
⚫horse shoe shape
⚫May be supported by
metal foil for stability
38
39. Forms
1 inch sheets
Uses
used to form base of the cast pouring
May be used to modify borders of trays
Properties
Tacky at room temp
39
Boxing wax
Transfer to
impression
41. Forms
Ropes manipulated at room temp
Applications
Add to the tray
� customize for pt mouth
� Comfort from sharp edges
� Control imp material in mouth
�Cover ortho bands and wires
� to register the bite
�Block out undercuts
41
Utility wax
42. Forms
Pencil shape
orange or yellow
Properties
hard and brittle – can reorient if
broken
Adhere temporarily the metal,
gypsum, resin – for fabrication or
repair
42
Sticky wax
