Dental Cements | Dental Chemistry PPT

January 22, 2013 | By | Reply More

Dental Cements | Dental Chemistry PPT

Power point presentation | lecture slide

Size:  463 KB





Applications of Dental Cements:

Cementing agent for permanent restorations.

Temporary restorations.

Liners and bases.

Cementing agents for orthodontic appliances.

Periodontal dressing.

Root canal fillers and sealers.

Pulp capping  agents.

Anterior restorations.



Requirement of Dental Cements

Adequate mechanical properties.

Non-irritating & non-toxic.


Insulating the pulp from thermal, electrical and chemical irritants.

Adhesive properties.

Esthetic properties.

Easy to manipulate.

Types of Dental Cements:

1- Cements based on Zinc Oxide.

2- Cements based on Alumino Silicate Glasses ( Ion leachable glasses ).

3- Other cements:

Resin cements.

Calcium – Hydroxide cements.

Cavity liners and Varnishes.

1- Cements based on Zinc Oxide

2- Cements based on Alumino Silicate Glasses.

Zinc Oxide Eugenol Cement .

Properties of ZOE:

1- Working and Setting time.

2- Film thickness.

3- Solubility and disintegration.

4- Strength.

5- Biological properties.

6- Bonding to enamel and dentin.

Modified Zinc Oxide Eugenol

1- Polymer reinforced cement       (Resin bonded cement).

Modified Zinc Oxide Eugenol Cements

Zinc Oxide Eugenol Cement .

Zinc Phosphate Cement.

Setting Reaction of Zinc Phosphate Cement.

Manipulative variables:

The heat of reaction is most effectively dissipated when the cement is mixed over large area of cooled glass slab.

Manipulative variables:

Initially mix small amounts of  powder with the liquid, then larger amount is incorporated,and finally smaller amounts are incorporated..desired consistency.

The liquid is kept in a tightly closed bottle .           


Properties of Zinc Phosphate  Cement:


2-Consistency and film thickness.


4- Solubility.


6-Thermal and electrical conductivity .

7-Biological properties.




Consistency and film thickness

Then consistency ( Inlay seating consistency)…….25µm.

Particle size of the powder.

Powder to liquid ratio.

Pressure applied during seating.


Thick Consistency ( Cement base)

Zinc Phosphate Cement

Zinc Phosphate Cement

Easy to mix.

Sufficient mixing and working time.

High compressive strength.

Irritant to the pulp.


No adhesive qualities (mechanical interlocking)

Susceptibility to acid attack.

Zinc Polycarboxylate Cement
(Zinc Polyacrylate Cement)

Setting Reaction of Zinc Polycarboxylate Cement


The proper powder /liquid ratio mixed on paper bad (1:1 or 2:1)

Dispensing of the liquid should be done immediately before mixing.

Cooled glass slap to extend working time.

The consistency of the mix is creamy .



The Viscosity decreases as the shear rate increase,i.e.the flow increases as the spatulation increases


Should be used only as long as it still has a glossy surface. 


Zinc Polycarboxylate Cement

Cementation of crowns and inlays.

Base under restorations .

Properties of Zinc Polyacrylate Cements:

1-Film thickness.


3-Solubility and disintegration.

4- Bonding.

5-Biological properties.


Glass Ionomer Cement

Setting Reaction of Glass Ionomer Cement:

Types of GIC :

Type I :

Luting cement for crowns and inlays.

Type II :

Restorative material

Type III :

Liner or base material.



The proper powder/liquid ratio is dispensed onto paper pad or glass slab,mixed for30-60 sec.

Encapsulated products are mixed for 10 mechanical mixer.

An extension of the working time to 9 minutes can be achieved by mixing on a cold slab.

The cement should not be used once a “skin” forms on the surface or when the viscosity increases noticeably.





Once the cement has achieved its initial set (about 7 minutes), the cement should be coated with the coating agent supplied with the cement.


Properties of GIC:

1- Working and setting time.

2- Mechanical properties:

3- film thickness.

4- solubility and disintegration .


6-Fluoride release.

7- Biological properties.



Glass Ionomer Cement

Adhesion to tooth structure.


High compressive strength.

Low solubility.

Technique sensetive

Moisture sensitivity.

Short working time and long setting time.

Low abrasion resistance.


Modification of GIC :

Metal Reinforced GIC .

Silver alloy admix.

Cermet cement.

Hybrid Ionomer (Resin-Modified GIC)  

Dual cure .

Tricure .

Compomer (Polyacid modified resin composite materials ).

Properties of Resin-Modified GIC :

Superior mechanical properties.

Better optical properties.

Prolonged working time and rapid set.

Adhesion to tooth structure.

Less moisture sensitivity.

Polymerization shrinkage.


Applications of Resin-Modified GIC :


Liners and bases.

Fissure sealants.

Core buld up.

Cementation of orthodontic brackets.

Retrograde root filling material.

Resin Cements

Types of resin-based cements

Self cure or auto-cure resin cements.


Light cure resin cements.


Dual-cure resin cements.


Insoluble in oral fluids.

Low viscosity.

Then film thickness (<25µm).

Easily manipulated.

Early setting.

Good bond strength to dentin.


High wear resistance.

Low polymerization shrinkage.

Biological compatibility.




Resin-bonded bridges.

All-ceramic crowns.

Ceramic inlays and onlays.

Composite inlays and onlays.

Orthodontic ceramic brackets.

Porcelain laminate veneers.

Porcelain repair.

Metal base denture.


Endodontic posts.


Calcium Hydroxide Cements


Calcium Hydroxide Suspension.

Two-paste system (chemically cured).

One-paste system (light cured).


Calcium Hydroxide Cements

Paste 1

Calcium hydroxide.

Zinc oxide .

Zinc stearate..

Ethyl toluene sulphonamide.



Paste 2

Glycol salicylate.

Titanium dioxide.

Calcium sulphate.

Calcium tungstate.

Properties of Calcium Hydroxide:

The freshly mixed cement is alkaline with a pH of 11-12 .

Compressive strength, tensile strength and elastic modulus are low.

Highly soluble.

Cavity Liners and Varnishes :

Cavity Liner :

Suspension of calcium hydroxide and some zinc oxide in a solution of natural or synthetic resin .

Cavity Varnishes and Liners:

Cavity Varnish:

Solution of natural gum(copal) ,rosin, or synthetic resin dissolved in an organic solvent such as acetone, chloroform or ether.

Applications :

To seal the dentinal tubules and prevent penetration of chemicals into the pulp.

To act as a temporary protection against the loss of constituents from the surface of a filling material.

To seal the dentinal tubules under amalgam restorations and prevent penetration of metallic ions and corrosion products into enamel and dentin.




Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Category: Dental, Powerpoint

WARNING: Any unauthorised use or reproduction of content for commercial or any purposes is strictly prohibited and constitutes copyright infringement liable to legal action.