ZOE -ZINC OXIDE EUGENOL

1. ZINC OXIDE EUGENOL
Dr.Athul Chandra.M
Dept. Conservative dentistry & Endodontics

7. Introduction
Use in dentistry since 1890s
Impression paste

8. • Cavity restoration

9. • Periodontal pack

10. • Low strength
• Least irritating to the pulp
• Obtudent effect to pulp on exposed dentine

11. ZOE
Type I :
for temporary
cementation
Type II :
Permanent
cementation
Type III :
temporary filling
+ thermal base
Type IV :
Cavity liner

12. Availability
Powder & liquid 2 paste system

13. Composition

14. Setting Reaction
• ZnO + H2O = Zn(OH)2
Dehydrated ZnO do not react with dehydrated eugenol

15. • The reaction proceeds as a typical acid – base
reaction
• Zn (OH)2 + 2HE → ZnE2 +2H2O
(Zinc hydroxide) ( Eugenol) (Zinc eugenolate)

16. • The Chelate formed --- Zinc eugenolate, is
an amorphous gel that tends to crystallize, thus
giving strength to the set mass.
• Structure of set cement: The set cement consists
of particles of zinc oxide embedded in a matrix of zinc
eugenolate.
• Setting time is around 4-10min.

17. FACTORS AFFECTING SETTING TIME
• Particle size: Smaller zinc oxide particles set
faster
• Powder to liquid ratio: Higher the ratio, faster
the set
• Addition of accelerators, e.g. alcohol, glacial
acetic acid and water makes the cement set
faster.
• Cooling the glass slab: Slows the reaction
• The set can be retarded by addition of glycol and
glycerine which act as retarders.

18. Advantages
ZOE cement is a very old and yet still useful material.
1. Its obtundent property makes it very useful for sedative and
temporary fillings.
[ Its use as a base has declined greatly. Other cements that
release fluoride have replaced ZOE.]
2. A reinforced ZOE base can withstand amalgam condensation
forces and support the overlying amalgam restoration.
3. Biocompatibility is very good because ZOE seals very well.
However, eugenol causes hypersensitivity reactions in some
patients. In addition, eugenol can irritate the skin of dental
personnel.

19. Manipulation
POWER – LIQUID SYSTEM
Powder/liquid ratio: 4:1-6:1 wt%
After shaking the bottles gently, measured quantity
of powder and liquid are dispensed onto a cool
glass slab.
The bulk of the powder is incorporated into the
liquid and saturated thoroughly in a circular motion
with a stiff bladed stainless steel spatula. Smaller
increments are then added until the mix is
complete.

21. TWO PASTE SYSTEM
• Equal lengths of each paste are dispensed and mixed
until a uniform colour is observed.
MODIFIED ZINC OXIDE EUGENOL CEMENTS
The modified ZOE cements are as follows:
o EBA- alumina modified cements
o Polymer reinforce ZOE cement
These were introduced to improve the mechanical
properties of zinc oxide eugenol cement.

22. PROPERTIES
• Compressive strength – relatively weak cements. Strength ranges from as low as 3 to
4 MPa up to 50-55 MPa.
• Tensile strength – ranges from 0.32 to 5.3MPa
• Modules of elasticity – 0.22 to 5.4GPa
• Thermal properties – thermal insulating properties are excellent for ZoE
• Solubility and disintegration – The solubility of the set cement is highest among the
cements (0.4% - wt) they disintegrate in oral fluids
• Adhesion – they do not adhere well to the enamel and dentin. This is one reason why
they are not often used for final cementation of crowns and bridges.
• Biological properties. PH and effect on pulp (pH is 6.6 to 8) they are the least irritating
of all cements. Pulpal responses are mild. They have soothing effect on the pulp

23. • Some zoe materials contain antibiotics
such as tetracycline, steroids as anti-
inflammatory agents.
• Their principal use is in pulp capping and
RCT.
• One product also contains barium
sulphate, which is radiopaque
Special products of zoe

24. ZINC OXIDE/ ZINC SULPHATE
TEMPORARY RESTORATIONS:
These are single component temporary
filling materials.
Supplied as a single component putty like
paste in small tubes, syringes or plastic
containers.
Commercial Names : Cavit (ESPE) ,
Caviton (GC) , Coltosol (Coltene) Use
in short term temporary restorations after
caries excavation, RCT etc.

25. COMPOSITION:
• zinc oxide;
• zinc sulphate -1- hydrate ;
• calcium sulphate – hemihydrates ;
• dibutyl phthalate (plasticizer) ;
• diatomaceous earth.
SETTING REACTION:
• sets by chemical reaction, it sets by reacting with water which it
absorbs from the mouth or from the cavity. Setting occurs slowly,
expands on setting.
SETTINGTIME :
• Surface hardens in about 20 to 30 mins. Complete hardening takes
place in 2-3 hrs.

26. PROPERTIES :
• May be white /pink colored.
• Has good initial sealing. as expands on setting, marginal seal is
further improved.
• Seal gradually dec. with time.
• strenght is low, its life is short,so material must be used for not
more than 1-2 wks.
MANIPULATION :
• material is dispensed, inserted into cavity using a cement carrier .
• container should be closed immediately,
• material is condensed into cavity using a plastic filling instrument
• as sets by hydration , cavity should not be fully dried before placing
the material.

27. It is probably the most commonly used
root canal filling material for primary
teeth.
• Walkholf paste
• KRI paste
• Maisto paste
• Vitapex
• Endoflas Colla cote Guedes
viva

28. viva

29. Properties ZOE Ca(OH)2 with
Iodoform (VITAPEX) KRI Paste
1. Restore at the same rate as the tooth
2. Harmless
3. Overfill resorbs
4. Antiseptic
5. Easily applied
6. Adheres to the wall
7. Easily removed
8. Radiopaque
9. No discoloration viva

30. THANK YOU
What do you think about Zoe??