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.
ADA Spa. No. 96. designates them as:
Type I: Fine grained for luting.
Film thickness should be
Type II: Medium grained for luting and
Film thickness should not more
1. Powder and liquid system.
2. Capsules of preproportioned
powder and liquid.
The ingredients are mixed and heated at
temperatures bw 1000‘C. and 1400’C.
After sintering ,the cake formed is cooled
This cause the material to crack which
helps in grinding of the material to a fine
This process is known as FRITTING.
@. 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
@. The aluminum complexes with the
phosphoric acid and the zinc ions to form
a zinc aluminophosphate gel.
@. The reaction is EXOTHERMIC.
@. Setting Time: 2.5-8 mins.
#. THERMAL PROPERTIES:
Good Thermal Insulator.
#. ADHESION PROPERTIES:
Not form a chemical bond with
enamel or dentin.
-At the time of cementation the pH is 2.
-Starting pH is 3.5.
-After 24 hours the pH is 5.5.