This document discusses the properties and use of zinc phosphate cement. It is the oldest luting cement, classified in two types - fine grained for luting and medium grained for luting and filling. The powder contains zinc oxide, magnesium oxide, and silica. The liquid contains phosphoric acid, water, and aluminum phosphate. When mixed, a reaction forms a zinc aluminophosphate gel. It has high compressive strength but no chemical adhesion and can irritate the pulp. Zinc phosphate cement is used for luting restorations and bases and as a temporary restoration material.

2.  INTRODUCTION
 CLASSIFICATION
 AVAILABLE AS
 COMMERCIAL NAME
 COMPOSITION
 MANUFACTURE
 SETTING REACTION
 PROPERTIES
 MANIPULATION
 ADVANTAGES
 DISADVANTAGES
 APPLICATION

3.  ADA SPECIFICATION NUMBER- 96.
 Zinc phosphate is the oldest of the
luting cements and thus serves as
a standard with which newer
cements can be compared.

4.  ADA Spa. No. 96. designates them as:
 Type I: Fine grained for luting.
Film thickness should be
25micrometer.
 Type II: Medium grained for luting and
filling.
Film thickness should not more
then 40micrometer.

5. 1. Powder and liquid system.
2. Capsules of preproportioned
powder and liquid.

6.  - Confit.
 - Harvard.
 - Zinc Cement Improved.
 - Modern Tenacin.

7. )(. POWDER:
- Zinc Oxide- 90.2%.
>. Principal constituent.
- Magnesium Oxide- 8.2%.
>. Aids in sintering.
- Other Oxide- 0.2%.
>.Improve smoothness of mix.
- Silica- 1.4%.
>.Filler.

8. )(. LIQUID:
- Phosphoric Acid- 38.2%.
>.React with zinc oxide.
- Water- 36.0%.
>.Control rate of reaction.
- Aluminium Phosphate- 16.2%.
>.Buffer.
- Aluminium- 2.5%.
- Zinc- 7.1%.

9.  The ingredients are mixed and heated at
temperatures bw 1000‘C. and 1400’C.
[SINTERING].
 After sintering ,the cake formed is cooled
quickly.
 This cause the material to crack which
helps in grinding of the material to a fine
powder.
 This process is known as FRITTING.

10. @. When the powder is mixed with liquid,
phosphoric acid attacks the surface of the
particles and releases zinc ions.
@. The aluminum in the liquid is essential for
cement formation.
@. The aluminum complexes with the
phosphoric acid and the zinc ions to form
a zinc aluminophosphate gel.

11. @. The reaction is EXOTHERMIC.
@. Setting Time: 2.5-8 mins.

12. #. COMPRESSIVE STRENGTH:
103.5MPa.[15,000GPa].
#. TENSILE STRENGTH:
5.5MPa.[800psi].
#. MODULUS OF ELASTICITY:
13.5GPa.
#. SOLUBILITY:
0.06%.

13. #. THERMAL PROPERTIES:
Good Thermal Insulator.
#. ADHESION PROPERTIES:
Not form a chemical bond with
enamel or dentin.
#.BIOLOGICAL PROPERTIES:
-At the time of cementation the pH is 2.
-Starting pH is 3.5.
-After 24 hours the pH is 5.5.

14. #. OPTICAL PROPERTIES:
OPAQUE.

15. 1. Stainless steel spatula and clean cool
glass slab are use for mixing.

16. 2. Mixing Time:- 1 min. 15 sec.
3. P/L Ratio:- 1.4gm/0.5ml.

17. 4. The powder is added in small increments.

18. 5. Mixing is done with stainless steel spatula
using brisk circular motion.
6. Each increments is mixed for 15-20 sec.

19. 7. A large area is covered during mixing in
order to dissipate the exothermic heat.

21. }{. Good compressive strength.
}{. Good thermal insulation ability.
}{. Dose not dissolve in oral fluids.

22. }{. No chemical adhesion.
}{. Pulp irritation.
}{. Poor esthetics.

23. ::- Luting for restoration.
::- High strength bases.
::- Temporary restoration.
::- Luting for orthodontic bands and
brackets.