1. CEMENTATION

2.  The mechanisms that hold a
restoration on a prepared tooth
can be divided into:
nonadhesive (mechanical)
luting, micromechanical
bonding, and molecular
adhesion.

3. Bonding Mechanisms
 Nonadhesive luting
– served primarily to fill the
gap and prevent entrance of
fluids

4.  Micromechanical
bonding
– necessary deep irregularities can
be produced on enamel surfaces by
etching with phosphoric acid solution
or gel; on ceramics, by etching with
hydrofluoric acid; and on metal, by
electrolytic / chemical etching, and
sandblasting

5.  Molecular adhesion
– involves physical forces
and chemical bonds
between molecules of two
different substances

6. TYPES OF CEMENTS

7. 1. Zinc Phosphate Cement
 possesses high
compressive
strength
 exhibits a pH of 3.5
at the time of
cementation which
contributes to
pulpal irritation
 needs cavity
varnish to reduce
exposure of pulp
to the cement

8. 2. Polycarboxylate Cement
 higher tensile
strength (resistance
to lengthwise stress)
 pH is also low (4.8)
 cause little pulpal
irritation
 shows moderately
high bond strength to
enamel and dentin
 bonds to stainless
steel, but not to gold

9. 3. Zinc Oxide Eugenol
 cause no pulpal
inflammation as
long as they make
no direct contact
with the pulp
 used as temporary
cements
 soluble than zinc
phosphate
 deteriorates more
rapidly in the mouth
than other cements

10. 4. Glass Ionomer Cement
 composed mainly of
calcium fluoro-
aluminosilicate glass
 compressive strength
and tensile strength
are quite good
 bacteriostatic
 releases fluoride at a
greater rate than
silicate cement
 pH is lower than zinc
phosphate which
cause post -varnish is not recommended
cementation -weakened by early
hypersensitivity exposure to moisture

11. 5. Resin Luting Cement
 composed of resin
matrix and a filler of
fine inorganic particles
 low filler content and
low viscosity
 virtually insoluble and
much stronger than
conventional cements
 high tensile strength
makes them useful for -problems encountered
micromechanically include excessive cement
bonding etched ceramic film thickness, marginal
veneers leakage because of setting
 dentin bonding agent is shrinkage, and severe pulpal
necessary prior to resin reactions when applied to
cement application
vital dentin

12. 6. Hybrid Ionomer Cements
 glass filler
particles react
with the liquid
during the
hardening
process
 combined the
strength and
insolubility of
resin with the
fluoride release
of glass ionomer

13. STEPS IN
CEMENTATION

14. Mix the cement in circular motion

15. Consistency of the cement should not be
too flowy or too sticky

16. A B
The inner walls of the crown are coated with a thin layer of
cement using the small end of an instrument (A)
or a brush (B).

17. Insert the crown on the abutment

18. Remove excess cement

19. Proximal contacts are tested with dental floss to
remove excess cement and ensure proper
interproximal spaces in between teeth