Zinc Oxide Eugenol Impression Material Quiz and Flashcards

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Questions and Answers

What is the primary function of the inert oils in Zinc Oxide-Eugenol impression materials?

To act as a plasticizer and decrease the irritating action of eugenol (correct)

To accelerate the setting reaction

To impart thermoplastic properties to the set impression

To produce a smoother, more coherent mix

Which component is responsible for imparting thermoplastic properties to the set Zinc Oxide-Eugenol impression?

Gum rosin (correct)

Eugenol

Accelerator (MgCl2 or CaCl2)

Zinc oxide

What is the primary component of the base paste (Tube 1) in Zinc Oxide-Eugenol impression materials?

Eugenol

Zinc oxide (correct)

Gum rosin

Inert oil

What is the purpose of the accelerator (MgCl2 or CaCl2) in Zinc Oxide-Eugenol impression materials?

To hasten the setting reaction Signup and view all the answers

What is the primary function of the filler (talc or kaolin) in Zinc Oxide-Eugenol impression materials?

To give the paste a specific consistency Signup and view all the answers

What is the main reason for using oil of cloves instead of pure eugenol in Zinc Oxide-Eugenol impression materials?

Oil of cloves produces less of a burning sensation Signup and view all the answers

What is the effect of a drop of water or alcohol on the setting time of a zinc oxide-eugenol impression material?

It decreases the setting time. Signup and view all the answers

Which of the following statements about the dimensional changes of a zinc oxide-eugenol impression material is correct?

It undergoes a negligible shrinkage of less than 0.1% during hardening. Signup and view all the answers

What is the relationship between the flow and setting time of a zinc oxide-eugenol impression material?

The relationship between flow and setting time is complex and depends on the specific product. Signup and view all the answers

Which of the following properties of a zinc oxide-eugenol impression material is mentioned in the text?

Elasticity Signup and view all the answers

What is the recommended disinfection procedure for a zinc oxide-eugenol impression material?

Immerse in 2% alkaline glutaraldehyde for the recommended time, then rinse. Signup and view all the answers

What is the effect of increasing the mixing time within limits on the setting time of a zinc oxide-eugenol impression material?

Increasing the mixing time decreases the setting time. Signup and view all the answers

Which of the following is a component of zinc oxide-eugenol impression materials?

Eugenol Signup and view all the answers

What is the primary role of eugenol in zinc oxide-eugenol impression materials?

To initiate the setting reaction Signup and view all the answers

Which of the following factors can affect the setting reaction of zinc oxide-eugenol impression materials?

All of the above Signup and view all the answers

What is the primary advantage of zinc oxide-eugenol impression materials?

Low cost Signup and view all the answers

Which of the following is a disadvantage of zinc oxide-eugenol impression materials?

Unpleasant taste Signup and view all the answers

What is the purpose of zinc oxide in zinc oxide-eugenol impression materials?

To provide rigidity and strength Signup and view all the answers

Study Notes

Introduction to Impression Materials

Dental impression is a negative replica of hard and soft tissues of the mouth, made with a material that sets while still in contact with the tooth and tissues.
A cast (model) is a positive replica of the oral hard or soft structures.

Purpose of Taking Impression

To study alignment of teeth
Construction of special (custom) tray
Treatment planning
Fabrication of indirect restorations

Types of Trays

Stock trays
Special tray

Desirable Properties of Impression Materials

Pleasant odor, taste, and acceptable color
Absence of toxic or irritant constituents
Adequate shelf life for requirements of storage and distribution
Not expensive
Easy to use with the minimum of equipment
Readily wets oral tissues
Setting characteristics that meet clinical requirements

Zinc Oxide Eugenol (ZOE) Impression Material

Composition

Tube 1 (Base): 80% Zinc oxide
Tube 2 (Accelerator): Oil of cloves or eugenol (15%), Inert oil, Gum rosin and oils (65%), Filler (talc or kaolin) (16%), Accelerator (MgCl2 or CaCl2) and water (4%)

Properties

Non-toxic, but eugenol can be irritant to patients
Negligible shrinkage (less than 0.1%) during hardening
Inelastic, cannot be used for recording undercuts
Adequate working time for border molding in the mouth
Adequate fine details and dimensionally stable

Manipulation

Equal length of each paste is dispensed on the mixing pad or glass slap
Mixed with a stiff stainless steel spatula for approximately 1 minute until a uniform color is achieved

Factors Affecting Setting Time

Temperature: increased temperature decreases setting time
Addition of water or alcohol: decreases setting time
Inert oils: increases setting time
Ratio of the two pastes: affects setting time depending on the product
Mixing time: increased mixing time within limits decreases setting time

Advantages

Adheres well to dried surfaces of compound, resin, and shellac bases
Sufficient resistance to build up borders if the tray is slightly deficient
Hard when set, can be taken in and out of the mouth repeatedly
Can be repaired

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Description

Learn about the composition and properties of Zinc Oxide-Eugenol pastes, a rigid impression material used in dentistry for making complete dentures. Explore how the paste hardens by a chemical reaction and its applications in denture preparation.

Zinc Oxide-Eugenol Paste in Dentistry