The document summarizes mixing techniques for five dental products: gypsum, glass ionomer cement, alginate, zinc phosphate cement, and zinc polycarboxylate cement. For each product, it describes the required materials, mixing procedure, mixing time, working time, and precautions. The procedures involve mixing powder and liquid components by hand or mechanically to achieve a homogeneous mix within optimal working times before the materials set. Precautions are noted to avoid air bubbles and ensure proper ratios, temperatures, and timelines for effective results.

1. •In the Name of Allah Who is the most Merciful and the
most
•Beneficial

2. MIXING TECHNIQUES OF FIVE DENTAL
PRODUCTS
• By
Najib Ahmad Dawar
Roll #: 66
Khyber College Of Dentistry
Peshawar (Pakistan)

3. • The Process by which two or more
components are mixed together in order
to get a homogeneous mix. e.g.
• Mixing of powder & liquid components,
• Mixing of two pastes &
• The mixing of paste & liquid
components.
Wor king Time
• The time available for mixing and
manipulating a material.

4. Mixing Techniques Of Five Dental
Products Which I Covered In
Presentation
1 Gypsum
2 Glass Ionomer Cement
3 Alginate
4 Zinc Phosphate Cement
5 Zinc Polycarboxylate Cement

5. 1-Gypsum mixinG:
• Mixed by two pr ocess:
• Manual Pr ocess ( Hand Mix)
• Mechanical Pr ocess

6. Requirements:
Robber Bowl, Spatula, Water &
Powder.
Pr ocedure::
• Take a measured quantity of
water in the r ubber bowl
• Add powder to the Bowl.

7. • Settle it for 30 sec with out spatulation.
• This technique minimize the chances of
Air interruption.
• Then spatulation starts and wipe the
powder with the inside of the bowl with a
spatula to insure wetting of the powder
and minimizes the Air entrapped.
• Spatulation continues until all the powder
is uniformly wetted and mix..
• Mixing time is 1min at 2rev/sec.
• Two setting Times:
• Initial setting time
• Final setting time

9. • Mechanical mixing
is done under
vacuum mixer.
• It gives stronger
and denser Mix.
• No chances for Air
to entrap in the Mix.

10. Precautions:
• The mixing equipment must be clean.
• Flexible plastic bowl should be used.
• Wide bladed spatula should be used.
• No air should be trapped in the Mix.
• The material should be used as soon
as possible after mixing since its
viscosity increases and will reach a
stage where the material is
unworkable.

11. 2-GLAss iOnOmER
CEmEnT mixinG
Requir ements:
Powder & Liquid, Glass slab or Non absorbable
Treated paper pad & plastic or ceramic
spatula.
• Consists of Powder & liquid
• If the liquid is the viscous carboxylic acid then
P/L ratio of 1.3:1 to 1.35:1 is used,
• If the liquid is water then W/P ratio 3.3:1 to
3.4:1 is used.
• The P/L ratio also depends on application of
the cements…
• lining consistency
• luting consistency

12. • For lining consistency the P/L ratio is 3:1
• And
• For luting consistency the P/L ratio is 1.5:1
• Powder should be divided into two equal
parts….
• Half of the powder will be carried and
mixed with liquid with a stiff spatula so that
powder is covered with liquid..
• After this the 2nd half is added and keep on
mixing. Until get the desired consistency.
• mixinG TimE:
• 30-60sec.
• WORKinG TimE:
• 2 minutes
• Immediately carry to the prepared cavity
b/c the working time after mixing is only
2min.

13. Encapsulated products are usually mixed for 10sec in
mechanical mixer and dispensed directly onto the
tooth restoration.

14. Precautions:
• There should be no evaporation of water.
• A good mix should have a glassy surface, this
indicates the presence of poly acids which
ensures bonding with the tooth, but a mix with
a dull surface is discarded as it indicates
prolong mixing which reduces the adhesion.
• If the liquid contains polyacids, it should not
be placed in a refrigerator as it becomes very
viscous.
• The glass slab should not be below the dew
point, as moisture may condense on the slab
and changes the acid water balance.
• Never use stainless steel spatula as it is
composed of metals which may react with
Glass Ionomer cement .Always use plastic or
ceramic spatula…

15. 3-ALGinATE mixinG
• Requirements: A clean flexible plastic Bowl,Wide
bladed spatula and a Plastic tube containing
water
• Alginate are supplied as powder which are mixed
with water
• A plastic measuring cylinder is used for the
correct volume of water
• An alginate powder is also supplied in small
sachets.
• Each sachet are sufficient for one impression.

16. • After proportioning the water and powder
are mixed together in a plastic mixing bowl
using a wide bladed spatula
• Rapid spatulation is required to give
thorough mixing and an alginate sol of
creamy consistency is formed.
• Then pour a water in the measuring cylinder
up to point 1 leaving 1 part in the cylinder…
• Mixing is started with a stirring motion to
wet all the powder.
• Once the powder has been moistened then
rapid spatulation with the side should be
done…

17. • Spatulation with sides will help to:
• Remove most of the air bubbles…
• Dissolve alginate from the surface and
complete their dissolution.
• After the material gain creamy consistency
…stop spatulation…
• Mechanical devices are also available for
spatulation alginate. their main advantage
are…
• Speed
• Convenience
• Elimination of human variables.

18. • Pr ecautions::
• Rapid spatulation is required
• Spatulation with the sides is done
• Correct volume of water and powder is
required.
• The water powder ratio specified by the
manufacturer should be used.

19. 4-ZinC phOsphATE
CEmEnT mixinG
Mixing Requirements:
Large Narrow Bladed Stainless
steel
spatula, Cooled Thick Glass slab,
mixinG::
• Its Mixing is an exothermic process.
• Incorporate the proper amount of powder
into the liquid slowly on a glass slab to
attain desired consistency…
• For Cavity Lining P/L is 3.5:1
• For luting a more thinner

20. • We divide the powder into increments
Smaller, larger and then smaller for
proper dissipation of heat.
• 1st incorporate a small increment of
powder into liquid minimum heat is
evolved.
• Then larger increment of powder is
added to further saturate the mix.
• Finally a smaller increment of powder
is added to achieve the desired
consistency of cement.

21. • The mix procedure begins with a Small
one, then larger one and ends with a
small one to compensate heat and to
achieve slow neutralization.
• The reaction is neutralization type.
• Always use thick glass slab to slow
down the process of temperature
change
• For increasing the working time we use
cold glass slab or frozen glass slab.
• Mixing Time:
• 60-90 sec are enough for mixing.
• Working Time
luting -2.5 minutes
lining – 2 minutes

22. • Mix over a large area to dissipate
the generated heat as this heat
will accelerate the setting time.
• The cap from the liquid bottle
should be removed enough to
dispense sufficient liquid for one
mix. ,and then replaced
immediately

23. • If the liquid is placed open for a
long time the water will be
either lost or gained depending
upon the humidity. which will
alter the setting characteristics
and physical properties.

24. 5-ZinC pOLy
CARbOxyLATE CEmEnT
mixinG
Requirements:
Mixing Requirements:
Large Narrow Bladed Stainless
steel
spatula, Cooled Thick Glass
slab,

25. Mixing::
• Available as powder and liquid or
precapsulated form.
• Powder is shaken gently
• Powder is dispensed on paper pad or
glass slab
• A bulk of powder i.e. 90% Of the powder
is added to the Liquid immediately so
that the liquid particles do not
evaporate.
• P/L ratio is 1.1,1.5:1 or 2:1and it can be
increased according to the demand.
• The remainder of the powder is mixed in
order to achieve the desired
consistency.
• It should be spread over a small area.

26. • It should be used immediately after
mixing b/c working time is only 3min at
22 centigrade.
• Working time can be increased by using a
cool glass slab.
• Normally it ranges b/w 2.5-6 mins but can
be increased up to 10-15 mins by using
chilled glass slab.