Cementation

1. CEMENTATIONCEMENTATION

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

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

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

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

6. TYPES OF CEMENTSTYPES OF CEMENTS

7. 1. Zinc Phosphate Cement1. Zinc Phosphate Cement
possesses high possesses high
compressive compressive
strengthstrength
exhibits a pH of 3.5 exhibits a pH of 3.5
at the time of at the time of
cementation which cementation which
contributes to contributes to
pulpal irritation pulpal irritation
needs cavity needs cavity
varnish to reduce varnish to reduce
exposure of pulp exposure of pulp
to the cementto the cement

8. 2. Polycarboxylate Cement2. Polycarboxylate Cement
higher higher tensile tensile
strengthstrength (resistance (resistance
to lengthwise stress)to lengthwise stress)
pH is also low (4.8)pH is also low (4.8)
cause little pulpal cause little pulpal
irritationirritation
shows moderately shows moderately
high bond strength to high bond strength to
enamel and dentinenamel and dentin
bonds to stainless bonds to stainless
steel, but not to gold steel, but not to gold

9. 3. Zinc Oxide Eugenol3. Zinc Oxide Eugenol
cause no pulpal cause no pulpal
inflammation as inflammation as
long as they make long as they make
no direct contact no direct contact
with the pulpwith the pulp
used as temporary used as temporary
cementscements
soluble than zinc soluble than zinc
phosphatephosphate
deteriorates more deteriorates more
rapidly in the mouth rapidly in the mouth
than other cementsthan other cements

10. 4. Glass Ionomer Cement4. Glass Ionomer Cement
composed mainly of composed mainly of
calcium fluoro-calcium fluoro-
aluminosilicate glassaluminosilicate glass
compressive strength compressive strength
and tensile strength and tensile strength
are quite goodare quite good
bacteriostaticbacteriostatic
releases fluoride at a releases fluoride at a
greater rate than greater rate than
silicate cementsilicate cement
pH is lower than zinc pH is lower than zinc
phosphate which phosphate which
cause post cause post
cementation cementation
hypersensitivityhypersensitivity
-varnish is not recommended-varnish is not recommended
-weakened by early -weakened by early
exposure to moisture exposure to moisture

11. 5. Resin Luting Cement5. Resin Luting Cement
composed of resin composed of resin
matrix and a filler of matrix and a filler of
fine inorganic particlesfine inorganic particles
low filler content and low filler content and
low viscositylow viscosity
virtually insoluble and virtually insoluble and
much stronger than much stronger than
conventional cementsconventional cements
high tensile strength high tensile strength
makes them useful for makes them useful for
micromechanically micromechanically
bonding etched ceramic bonding etched ceramic
veneersveneers
dentin bonding agent is dentin bonding agent is
necessary prior to resin necessary prior to resin
cement applicationcement application
-problems encountered -problems encountered
include excessive cement include excessive cement
film thickness, marginal film thickness, marginal
leakage because of setting leakage because of setting
shrinkage, and severe pulpal shrinkage, and severe pulpal
reactions when applied to reactions when applied to
vital dentinvital dentin

12. 6. Hybrid Ionomer Cements6. Hybrid Ionomer Cements
glass filler glass filler
particles react particles react
with the liquid with the liquid
during the during the
hardening hardening
process process
combined the combined the
strength and strength and
insolubility of insolubility of
resin with the resin with the
fluoride release fluoride release
of glass ionomerof glass ionomer

13. STEPS IN STEPS IN
CEMENTATIONCEMENTATION

14. Mix the cement in circular motion

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

16. 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).
A 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