This document discusses dental waxes, including their composition, properties, uses, advantages, and disadvantages. Dental waxes are mixtures of natural and synthetic materials that are soft and mouldable at elevated temperatures but harden at room temperature. They are used to form patterns for dental appliances and restorations. Key properties include melting point, flow value, and thermal conductivity. Common uses are impression wax, modelling wax for dentures, and inlay wax for dental restorations. Advantages are easy manipulation and removal without residue. Disadvantages include poor thermal properties leading to dimensional errors.

1. K O F I N T I B A F F O U R A B O A G Y E
S U N D A Y N A N C Y E R E I B I
DENTAL WAXES

2. INTRODUCTION
• Waxes are thermoplastic materials which are
normally solids at room temperature but melt,
without decomposition, to form mobile liquids.
• The waxes used in dentistry normally consist of two
or more components which may be natural or
synthetic waxes, resins, oils, fats and pigments.
• Blending is carried out to produce a material with
the required properties for a specific application.

3. • They are, essentially, soft substances with poor
mechanical properties.
• Their primary uses in dentistry are to form
patterns of appliances prior to casting.
• The wax pattern defines the shape and size of
the resulting appliance.

4. REQUIREMENTS OF WAX-PATTERN
MATERIALS
• The wax pattern must conform to the exact size,
shape and contour of the appliance which is to
be constructed.
• No dimensional change should take place in the
wax pattern once it has been formed.
• After formation of the casting mould, it should be
possible to remove the wax by boiling out or
burning without leaving a residue.

5. • The wax should be uniform when softened
• The color should contrast with die materials or
prepared teeth.
• The wax should not fragment into flakes or
similar surface particles when it is molded after
softening.

6. COMPOSITION OF WAXES
• Dental waxes are a blend of natural and
synthetic materials.
• Natural waxes may be of mineral, animal or
vegetable origin.
• Synthetic waxes are nitrogenous derivatives of
fatty acids or polymers of ethylene oxide

7. NATURAL COMPONENTS
• Mineral: Paraffin wax and microcrystalline wax are
hydrocarbons obtained from petroleum residues
following distillation.
• Animal: Beeswax is derived from honeycombs and
consists of a partially crystalline natural polyester. It
is often blended with paraffin wax to render the
material less brittle.
• Plant: Carnauba wax and candelilla wax are derived
from trees and plants. They are blended with paraffin
wax in order to control the softening temperature.

8. CLASSIFICATIONS
• The wide variety of dental waxes can be classified into two
groups, those used primarily in the clinic and those used in
commercial dental laboratories.
• Clinical products include bite registration wax, disclosing wax
(also known as pressure indicating paste), utility waxes for
altering and adapting impression trays, and low-melting type
I inlay waxes used in the mouth for direct-waxing processes
for pattern production.
• Laboratory products include boxing wax , baseplate wax ,
sticky wax , beading wax, utility wax, and hard, medium, and
soft type II inlay-type waxes for making patterns on patients’
models using the indirect wax technique .

9. CLASSIFICATIONS
• Dental waxes can also be classified in one of
three types
• Pattern wax (inlay, casting, and baseplate
types)
• Processing wax (boxing, utility, and sticky
types)
• Impression wax (bite registration and
correction types)

10. PROPERTIES OF WAXES
Can be grouped mainly under thermal and
mechanical properties.
• Mechanical properties
• Flow value: determines the mouldability and
stability of a wax. It depends on temperature,
force applied and the period of application.
Materials should, ideally, exhibit considerable flow
at the moulding temperature but should show little
or no flow at mouth temperature or room
temperature so that they are not easily distorted.

11. • Brittleness: depending on the procedure,
waxes may be brittle or tough. In some cases,
for example denture waxes, toughness is
required since the wax denture base may have
to be removed from a slightly undercut cast
many times without fracturing. In other cases,
such as inlay waxes, brittleness is preferred in
order that the wax will fracture rather than
distort on removal from an undercut cavity.

12. THERMAL PROPERTIES
• Melting point: some waxes begin to melt at 37oC. Others
melt above 40oC. Paraffin (40-70oC), microcrystalline (60-
90oC), bee wax (65-70oC)
• Solid–solid transition temperature: sometimes referred to as
the softening temperature. This involves a change in crystal
structure, accompanied by a change in mechanical
properties i.e. the wax is converted from a relatively brittle
solid to a much softer, mouldable form. For many
applications of waxes the softening temperature should be
just above mouth temperature so that the material may be
introduced into the mouth in a mouldable state but will
become relatively rigid at mouth temperature.

13. • Thermal conduction: Waxes are very poor thermal
conductors and must be maintained above the solid-solid
transition temperature for long enough to allow thorough
softening to occur throughout the material before moulding is
attempted.
• The coefficient of thermal expansion: higher in waxes than
that of any dental material. This is a potential source of error
in dental procedures as it may lead to thermal contractions.
For example, a wax pattern would shrink considerably on
cooling from its solidification temperature to room
temperature.

14. • The low thermal conductivity values of the materials result in
solidification of the surface layers of the wax well before the
bulk becomes rigid. This reduces the magnitude of the
thermal contraction and produces significant internal
stresses. Dimensional changes may occur due to the
stresses.
• Solutions:
• In order to achieve even heating it is important that the wax
should be held in the warm rising air above the flame and not in
the flame itself.
• Heating in warm water causes more regular softening.
• The ideal method for softening wax is to use a wax annealer.
This is a thermostatically controlled oven which keeps the wax
at a constant temperature, just above the softening point, ready
for use.

15. MANIPULATION OF INLAY WAXES
• To manipulate inlay wax, dry heat is preferred to the use
of a water bath. Using a water bath can result in the
inclusion of droplets of water, which can splatter on
flaming, smear the wax surface during polishing, and
distort the pattern during temperature changes.

16. USES
• Impression wax: used to create accurate representation
of oral structures to help design and construct
prostheses
• Carding and boxing-in wax: These are waxes with a flow
value at room temperature. They are easily mouldable
without the need for heating. They are used by
manufacturers to attach artificial teeth to the mounts on
which they are supplied. Also used in the dental
laboratory for ‘box in’ impressions prior to casting.

18. • Sticky wax: It is used in the laboratory for a variety of
applications where joining is required. For example, joining
together metal parts prior to soldering and joining fragments
of a broken denture prior to the repair of procedure.
• Modelling wax: consist mainly of mixtures of paraffin wax
and beeswax and have melting points in the range 49–58ºC.
It is used as a pattern material and for the registration of jaw
relationships in the construction of dentures. For example,
artificial teeth are mounted on the wax rim and to check the
suitability of the wax denture at the ‘try in’ stage.
• Type 1 soft wax
• Type 2 hard wax
• Type 3 extra hard

19. This shows modelling wax being used to make a trial denture which the dentist
can use for trying into the mouth of the patient. It will then become the
‘template’ for the acrylic denture. The artificial teeth have already been set up
in these wax dentures.

20. The sheet casting wax is supplied in sheets which have
been rolled to a precise thickness, according to the metal
gauge required. Some metal components of partial
dentures are formed in wax on the model.

21. • In lay waxes: The composition of in lay wax is similar to
that of modelling wax. They used for the preparation of
in lay patterns either by the;
• Direct technique (in the mouth)
• Indirect technique (outside the mouth)
• Inlay waxes are also used widely in the dental laboratory
to prepare casting patterns for metallic restorations,
either crowns or bridges.

22. ADVANTAGES OF WAXES
• Easily manipulated
• Excesses easily removed by boiling or burning
without leaving a residue
• Does not irritate soft tissues
• Can be used to relieve pain and irritation caused
by orthodontic appliances

23. DISADVANTAGES OF WAX
• Poor thermal conduction and high coefficient of
thermal expansion can lead to
• High internal stresses
• Dimensional changes
• Errors in dental procedures as due to thermal
contractions which may affect the accuracy of
restorative materials

24. REFERENCES
• Applied dental materials. – 9th ed. / J.F. McCabe, A.W.G.
Walls.
• Phillips’ science of dental materials / Kenneth J.
Anusavice, Chiayi Shen, H. Ralph Rawls.—12th ed.