a brief summary of available dental cements and their applications

1. Dental
Cements
Dr.Mohammad Abdulsamad
Prosthodontics department

2. Outlines
Introduction
Mechanisms Of bonding
Zinc Phosphate cement
Zinc Oxide Eugenol Cement
Zinc Polycarboxylate
Glass Ionomer Cement
Resin cements
Recent advancements in dental cements
Conclusion

3. “Although dental cements are used only in
small quantities, they are perhaps the most
important materials in clinical dentistry
because of their application as luting cements,
Cavity liners, bases, and as restorative
materials”

4. Ideal
cement
properties
Biologically
compatible
Release of fluoride and other
minerals (Ca-PO)
Good manipulation
properties
High strength in
compression, tension and
shear
Strong bond: Chemical and
micromechanical
interlocking
Good fracture
Toughness

5. Mechanisms of Bonding
Non Adhesive
(mechanical bonding)
Micromechanical
bonding
Chemical bonding
(molecular Adhesion)

6. Non adhesive
(mechanical) luting
● It holds the restoration in place by
engaging small irregularities on the
surfaces of both tooth and
restoration.

7. Micromechanical
bonding
● Requires etching on enamel surfaces
with a phosphoric acid solution or gel,
and with a hydrofluoric acid on
ceramics
● on metals, electrolytic etching,
chemical etching, air abrading can be
used to obtain the microporosity

8. Chemical bonding
(Molecular adhesion)
● Involves chemical bonds between
molecules ( ionic, covalent )
● Because of the low physical properties
this bond have, it’s considered an
Auxiliary bond to enhance mechanical
or micromechanical retention and
reduce microleakage.

9. Timeline of dental cements
Zinc Phosphate
Zinc oxide eugenol
Zinc polycarboxylate
Glass Ionomer
Resin cement
(8th generation)
1902
1964
2010
1950 - 1960
1972

10. Zinc Phosphate Disadvantages
Advantages
• Pulpal irritation
• Lack of antimicrobial effect
• Brittleness
• Mixed easily
(manipulation is less critical )
• Good physical strength
• Relatively cheap
•Powder : mainly Zinc Oxide + Magnesium oxide + pigments
•Liquid : Phosphoric acid + Water + Aluminum
Composition

11. Zinc Phosphate cement applications
The historic zinc phosphate cement has fallen
out of use.
● Used to be the standard in permanent
fixed cast alloy and porcelain restorations
● liner or base

12. Zinc Phosphate cementation
considerations
● Mixing ratio: 2.5 powder / 3.5 liquid
● Dry field is a must until complete hardening
● A fresh mix is highly acidic 1 – 2 Ph > pulp may need protection > varnish >
reduced retention

13. Zinc Phosphate cementation
considerations
● The Reaction is Exothermic = reduced
setting time > cold glass slap needed
● Powder is divided to small increments
and each increment is mixed slowly and
across a wide area = Reduce the acidity
● Excess cement is removed after
hardening
● Will irritate the gingiva if left in the
sulcus

14. Advantages
Disadvantages
• Sedative and non
irritating effect on the
pulp
• High sealing capacity
• Antibacterial action
Zinc oxide eugenol
• Low strength and
abrasion resistance
• High solubility in oral
fluids
• Potential allergic
reaction
Composition
• Powder : Zinc oxide
• Liquid : Purified eugenol or clove oil + >1% alcohol or
acetic acid

15. Zinc oxide eugenol applications
● provisional cementation of crowns and fixed
partial dentures
● as a cavity liner
● for retaining fixed prostheses on implant-
supported abutments, which facilitates
retrievability of the prostheses
● Mixing ratio: 3.1 Powder / 4.1 liquid

16. Advantages
• Chemical bond to
tooth structure
• Non irritant effect
on the pulp
Disadvantages
• Critical manipulation
• Short working time
• Lower compressive
strength
• Viscous nature (not easy
to handle and clean)
Zinc poly carboxylate
Composition
• Powder : zinc oxide + tin or magnesium oxide
• Liquid : 40% aqueous solution of polyacrylic acid

17. Zinc poly carboxylate applications
much like zinc phosphate this cement is not
widely used anymore.
● Could be used for the cementation of cast
alloy and porcelain restorations
● orthodontic bands
● cavity liner and base material
● provisional restorative materials

18. Zinc poly carboxylate cementation
considerations
● Mixing ratio: 1.5 powder / 1.0 liquid
● The tooth is isolated and dry until the
complete setting of cement.
● Accurate proportions are important
● Rapid mixing 30 – 40 sec
● The mix is placed on both, tooth and
restoration while still glossy
● Excess is removed after complete setting

19. Advantages
• Chemical bonding to
the tooth
• Easy manipulation
• High strength
• Fluoride release
Disadvantages
• Pulp irritation and
hypersensitivity
• High solubility in oral
fluids
• Slow setting process
• High moisture
sensitivity
Glass Ionomer cement
Composition
• Powder : Calcium fluoroaluminosilicate glass
(fluoride content 10%- 16%)
• Liquid : Aqueous solution of Polyacrylic acid +
5% - 10% tartaric acid

20. Resin modified glass ionomer cement
Resin is added to the conventional
GIC with less polyacrylic acid which
results in
Advantages
Faster setting
Increased
resistance to
moisture
Bonding to
composite
materials
More
Translucency
Disadvantages
More water
absorption and
expansion
Less fluoride
release

21. Glass ionomer cement applications
Recently the RMGI is used more commonly than the conventional GIC to :
● Permanent cementation of metal and porcelain crowns and bridges especially in
patients with poor plaque control or an active carious lesions
● Orthodontic bands
● liners and base materials
● Restorative material

22. Glass ionomer cement applications
Conventional GIC Powder and liquid RMGI Capsules of RMGI

23. Glass ionomer cementation
considerations
● Mixing ratio: 1.3 Powder / 1.0 liquid
● Tooth surface should be clean and free from saliva
(but not completely dehydrated)
● Moisture = weakening of the cement isolation required
● Crowns margins should be protected by a varnish or a sealant for 24 hours to
prevent the cement from absorbing water before the complete setting.
● Excess cement is removed as soon as the seating is complete.

24. Resin luting cements
Resin luting
cements
composition
Cement
(composite)
- A composite made of resin matrix and an inorganic
filler
•- (lower filler content and lower viscosity than the
restorative composites)
Adhesive
system
1 - Etchants : most commonly 37% phosphoric acid
or ( acidic monomer = etchant + primer) in self etch
systems
2 - Primer : monomers in water soluble solvents
(acetone, ethanol and water)
3 - bonding agent : unfilled fluid resin

25. Resin luting cements (Adhesives classifications)
Source : E. Sofan et al Classification review of dental adhesive systems: from the IV generation to the universal type
Annali di Stomatologia 2017;VIII (1):1-17
Generation Number of steps
Surface pre-
treatment
Components Shear bond strength (MPa)
1st 2 Enamel etch 2 2
2nd 2 Enamel etch 2 5
3rd 3 Dentine conditioning 2 - 3 12 - 15
4th 3 Total etch 3 25
5th 2 Total etch 2 25
6th 1 Self-etch adhesive 2 20
7th 1 Self-etch adhesive 1 25
8th 1 Self-etch adhesive 1 Over 30

26. Resin luting cements (Adhesives classifications)
Source : Catherine Stamatacos, DDS; and James F. Simon, DDS, Med. Cementation of Indirect Restorations: An Overview of Resin
Cements. Compendium January 2013 Volume 34, Issue 1
Resin cement Curing method Characteristics Indications
Light-Cure
• Photo-initiator. Activated by light • Increased working time
• Decreased finishing time
• Color stability
• Esthetic restorations
• Metal free restorations
• Cementing thin, translucent ceramics
Dual-Cure
• Chemical and light • Bond strength
• Esthetics
• Ease of use
• Cementing thick opaque ceramic
• Metal-free restorations
Chemical-Cure
• Chemical reaction of two
materials mixed (self curing)
• Useful in areas where light-
curing is difficult
• Metal restorations
• Endodontic posts
• Ceramic restorations that prohibit curing unit
from adequately polymarizing the resin cement

27. Resin luting cements (Adhesives classifications)
Source : Catherine Stamatacos, DDS; and James F. Simon, DDS, Med. Cementation of Indirect Restorations: An Overview of Resin
Cements. Compendium January 2013 Volume 34, Issue 1
Resin
cement
Adhesive scheme Characteristics
Total-Etch
30-40% phosphoric acid-etch, then adhesive is applied • Excellent cement to tooth bond strength
• Reduced microleakage
• Long term predictability
• Requiers multi-steps application technique
Self- Etch
Self-etching primer, then mixed cement is applied • Ease of use
• Less technique sensitivity
• Good bond strength
Self-
Adhesive
"One component" phosphoric acid grafted into resin • Able to bond to untreated tooth surfaces
• "Selective etching" can be incorporated for improved
bond strength

28. Advantages
• Chemical and
micromechanical bonding
to tooth
• Insoluble in the oral
fluids
• Higher physical strength
Disadvantages
• Pulpal sensitivity
• Microleakage due to
shrinkage
• Complicated excess removal
especially in subgingival
margins
• High film thickness
• Technique sensitive
Resin luting cement

29. Resin luting cements applications
● most useful in anterior ceramic veneers.
● for all-ceramic prostheses where the
esthetic demand is very high.
● For post and core build up and
cementation.
● For orthodontic brackets.

30. Cement
properties
Film
thickness
(mm)
Setting
time (min)
Solubility
(Wt%)
Strength (MPa)
Compressive Tensile
Mechanism of
bonding
Biologic
effect on
pulp
(Indirect)
Effect on
bacteria
Zinc Phosphate 25 - 35 5 - 14 0.2 80 - 100 5 - 7 Mechanical Irritant Non
Zinc Oxide
Eugenol
25 - 35 2 - 10 1.5 2 - 35 1 - 2 Mechanical Sedative Antimicrobial
Zinc
polycarboxylate
20 - 25 6 - 9 0.06 55 - 85 8 - 12
Mechanical
+
chemical
Non-irritant Non
Glass Ionomer
Cement
25 - 35 6 - 9 1 90 - 140 6 - 7
Mechanical
+
chemical
Irritant
Bacteriostatic
*
Resin cement < 25 2 - 4 0 - 0.01 70 - 172 30 - 40
Micromechanicl
+
chemical
Irritant Non

31. Recent advancements
in dental cements
Nanomodifications of glass
ionomer cement powder
Nanomodified resin-modified
glass ionomer cements
7% arginine addition to
The adhesive systems
Bioactive glass (BAG) as a
filler in adhesive systems
Source: Advanced Dental biomaterials (2019)

32. Recent advancements in dental cements
Nanomodifications of
glass ionomer cement
powder
• The addition of Nanosized
fluoroaluminosilicate glass :
• Decreased the setting time
• Improved the mechanical properties of the
set GIC
• Increase the chemical bond strength
between the tooth and GIC

33. Recent advancements in dental cements
Nanomodified resin-modified
glass ionomer cements
• Less susceptible for fracture and
expansion
• Better esthetics
• But still inferior mechanical properties to
resin cements and lower fluoride release to
conventional GIC
• Studies indicates no significant difference
between the survival rates of RMGICs and
nano-RMGICs
• To date, no statistically significant difference
has been observed between the fluoride
Release from nano-RMGICs and
conventional RMGICs.

34. Recent advancements in dental cements
7% arginine addition to
The adhesive systems
• Adding 7% arginine to an adhesive
systems retain appropriate physical
and mechanical properties. Moreover,
it showed controlled release and
moderate recharge of arginine over a
prolonged period of time.
• Arginine was released from the
adhesive system at a rate and
concentration to exhibit Antibacterial
effect

35. Recent advancements in dental cements
Bioactive glass (BAG) as a
filler in adhesive systems
• Bioactiv glass (BAG) it consists mainly of silicon, calcium, sodium,
phosphorous,and oxygen
• have been used as dental adhesive to remineralize the tooth
surface
• Bonds chemically to the tooth
• Releases calcium and phosphate ions, which have
remineralization effects on the demineralized Tooth
• dissolution of BAG in an aqueous environment releases alkali
ions, resulting in an increase in pH which gives BAG Antibacterial
and acid neutralizing properties
• BAG addition in the adhesives has been shown to prevent
demineralization of enamel due to the Ca and P ion releasing
ability, thereby preventing WSL.

36. Conclusion
Increase the physical and
chemical properties
Enhance the
biological potential
Implement antibacterial
and remineralizing
effects
We can say that so far, the advancements in dental cements
and adhesives are tremendous, but further research is
required to optimize the performance in clinical application
fully.

37. Thank You