Cements for restoratives Copper Cements Chemistry and Setting Clinical manipulation Mechanical and Biological properties Zinc Polycarboxylate Cement Chemistry and Setting Clinical manipulation of Polycarboxylate Cement Mechanical and biological properties Zinc Oxide Eugenol Cement Chemistry and Setting Clinical Manipulation Modified Zinc Oxide Eugenol Cements EBA-Alumina modified Cements Chemistry and Setting Clinical manipulation Mechanical and Biological Properties Polymer reinforced Chemistry and Setting Clinical Manipulation Mechanical and Biological Properties

2. CONTENTS
 Introduction
Cements for restoratives
Copper Cements
Chemistry and Setting
Clinical manipulation
Mechanical and Biological properties
Zinc Polycarboxylate Cement
Chemistry and Setting
Clinical manipulation of Polycarboxylate Cement
Mechanical and biological properties

3. Zinc Oxide Eugenol Cement
Chemistry and Setting
Clinical Manipulation
 Modified Zinc Oxide Eugenol Cements
o EBA-Alumina modified Cements
Chemistry and Setting
Clinical manipulation
Mechanical and Biological Properties
o Polymer reinforced
Chemistry and Setting
Clinical Manipulation
Mechanical and Biological Properties
conclusion

4. INTRODUCTION
 Dental Cement-
“ The substances that hardens to act as a base, liner, filling
material , or adhesive to bind devices and prosthesis to tooth
structure or to each other.” (GPT)
• First dental cement was introduced in 1785 by sorel.
• Created ‘Zink-oxide-chloric- cement’.
• Rostain and then Flak developed and introduced Zinc phosphate
Cement .

10. Properties
Mechanical properties
1) Compressive strength- 55 to 67 Mpa
2) Tensile strength- 2.4 to 4.4 Gpa or 6.2 Mpa
(less than half that of zinc phosphate cement)
 Not as brittle as zinc phosphate
 Plastic deformation potential is high that’s why more
difficult to remove excess cement after setting.
Film Thickness:-
 25 µm or less.

11. Solubility:-
 Solubility of this cement is low, but when exposed to organic acids such
as lactic acid of less than pH 4.5 the solubility markedly increases.
 Reduction in the P/L ratio results in higher solubility and
disintegration rate in the oral cavity.
Working time:-
 Shorter than the zinc phosphate cement.
 Approximately 2.5 min.
 Lowering the temperature of the slab can increase the working
time .
 But lowering the temp. of glass slab can result the acid to be get
thicken and increases the viscosity.

12. Setting time:-
 Ranges from 6 to 9 min.
 Acceptable for luting cement.
Biological properties:-
 pH of the cement is 1.7
 pH rises rapidly as the setting reaction proceeds.
 Larger size of the molecules of zinc polycarboxylate cement
limits its diffusion through the dentinal tubules.
 Thus imparts excellent biocompatibility equivalent to ZOE
cement.

13. Manipulation
 Powder to liquid ratio range from 1.5 parts of powder to 1
part of liquid by weight.
 Mixing should be done on the surface that doesnot absorb
the liquid.
 Glass slab is advantageous over paper pads supplied by
manufacturer.
 Because once the glass slab is cooled, it maintains temp. for
longer time.

16.  A dull-looking mixture means that an insufficient number of
unreacted carboxyl groups are available to bond to the calcium
in the tooth surface.
Retention of the cement
 Despite of a property of tooth adhesion this cement is not
superior to zinc phosphate cement in the means of
retention.
 Failure usually occurs at the cement- tooth interface with
zinc phosphate cement.
 The cement does not bond to the noble metal in the
chemically contaminated cast.

17.  Thus it is essential that this contaminated surface in the
cavity side of the casting be removed to improve wettability
and the mechanical bond at the cement metal interface.
 The surface can be carefully abraded with a small stone, or
it can be sandblasted with high pressure air and alumina
abrasive.
Removal of Excess Cement
 During setting, the zinc polycarboxylate cement passes
through a rubbery stage that makes removal of the excess
cement quite demanding.
 Excess cement should not be removed in this stage because
there are chances of cement gets pulled out of the crown.

18.  It can removed only after it becomes hard.
 The outer surface of the prosthesis be coated carefully with
a thin layer of separated medium, such as petrolium jelly ,
to prevent excess cement from adhering its surfaces.
 Another approach is to start removing excess cement as
soon as setting of the cement.
 The goal of doing all is this is to prevent excess cement
during rubbery stage.

19. Zinc oxide eugenol cement
 ADA specification no. 34
 These cements used extensively in dentistry since 1890s.
 Cements low strength.
 Least irritating to the pulp and have obtundant effect on dental
pulp.
CLASSIFICATION:
1. Type I ZOE – Temporary cementation
2. Type II ZOE – Permanent cementation
3. Type III ZOE– Bases
4. Type IV ZOE– Cavity liners and periodontal dressings.

20. Type I Cements
 Meant for the short term luting.
 Used for the cementation of provisional restorations
 It has low strength which favours the easy removal of temp.
prosthesis.
 To prevent, various types of carboxylic acids have been
used to replace eugenol content, such cements known as
non-eugenol cements.
Type II cements
• Meant for long term restorations
• Modified ZOE are used to substitute their lower strength

21. • There are two systems used in this way
• First system is that which substitutes the parts of the eugenol with
orthoethoxybanzoic acid and alumina added to the powder.
Type III cements
• Used for the interim period when the tooth is under going treatment or
until it is ready for the permanent restoration.
• Also used as bases under permanent restorations
Type IV cements
• Used as liners
• Sufficient powder must be added to achive its desirede properties.

22. Composition
Available as powder and liquid
Powder
POWDER WT% FUNCTION
Zinc Oxide 69% principal ingredient
White rosin 29.3% Reduces brittleness of
set cement
Zinc Stearate 1% Accelerator
Zinc acetate 0.7% Accelerator, improves
strength
Magnesium Oxide same as zinc oxide

27. Thermal Properties
Thermal Conductivity : Excellent thermal insulating properties and
almost same as for the human dentin.
Solubility
• Highest among the cements
• They disintegrate in the oral fluids
• Disintegration is due to hydrolysis of the zinc eugenolate
matrix
• Solubility is reduced by increasing the P/L ratio.
Film Thickness
• 25 µm
• Generally higher in cement and important for luting and
bases application.

28. Adhesion
 They do not adhere to tooth surface, hence can not used for
final cementation of the crown.
Biological Properties
 pH of the cement is 6.6 to 8
 Least irritating compare to other cements
 Mild irritant to the pulp
 Also bacteriostatic in nature and imparts soothing effect on
the pulp of deep cavities.

37. Conclusion
 Though cements are used in small quantities in oral
cavity , it should be used with at most care, as it is very
important.
 These are innumerable cements present with different
properties.
 One should know all the properties to use it in order to
give a successful restoration to the patient.

38. Thank You