Alginate Impressions Quiz

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What is the difference between a true solution and a suspension?

The dispersed phase in a suspension can't be seen by the naked eye.

Particle size of the dispersed phase is large in a true solution. (correct)

A true solution involves solid particles while a suspension involves liquid particles.

The dispersed phase in a true solution is insoluble in the dispersion medium.

How are reversible hydrocolloids different from irreversible hydrocolloids?

Irreversible hydrocolloids involve primary bond formation. (correct)

Reversible hydrocolloids are stronger than irreversible hydrocolloids.

Reversible hydrocolloids involve chemical reactions.

Irreversible hydrocolloids form secondary bonds upon gelation.

Which type of colloid involves a liquid dispersed phase instead of a solid?

Suspension

Emulsion (correct)

Gel

Sol

What defines hydrocolloids?

The particle size of the dispersed phase is smaller than in suspensions. (B) Signup and view all the answers

What causes agglomeration in hydrocolloids leading to gelation?

Decrease in temperature (A) Signup and view all the answers

In what state are hydrocolloids inserted in the mouth to record details?

Sol (B) Signup and view all the answers

What is the role of Sodium triphosphate in alginate?

Delays gel formation (A) Signup and view all the answers

Which type of alginate has a shorter working time?

Fast set (A) Signup and view all the answers

In the setting reaction of alginate, what is formed when Calcium sulfate reacts with Sodium triphosphate?

Calcium phosphate + Sodium sulfate (B) Signup and view all the answers

Which compound is involved in forming the set gel during the setting reaction of alginate?

Calcium alginate (C) Signup and view all the answers

What equipment is NOT typically used during the manipulation of alginate?

Plaster spatula (D) Signup and view all the answers

Which additive is commonly used in alginate for disinfection purposes?

Chlorhexidine (C) Signup and view all the answers

What is the clinical importance of removing the impression from the mouth with a snap removal?

To increase tear strength (B) Signup and view all the answers

Why should the impression be removed suddenly from the mouth?

To reduce permanent deformation (A) Signup and view all the answers

What is the primary difference between irreversible and reversible hydrocolloids in terms of gelation?

Irreversible hydrocolloids undergo gelation through a chemical reaction, while reversible hydrocolloids undergo gelation through a physical reaction. (D) Signup and view all the answers

How does the water content of impressions affect gypsum materials?

Inhibits setting and results in a soft surface (B) Signup and view all the answers

What are the advantages of alginate impression material?

Inexpensive, easy to use, hydrophilic, no need for custom trays (A) Signup and view all the answers

What is the mode of setting for alginate impression material inside the patient's mouth?

Faster at tissue side then tray wise (D) Signup and view all the answers

Which component serves as the main reaction ingredient in Na alginate or K alginate to form gel in irreversible hydrocolloids?

CaSO4.2H2O (B) Signup and view all the answers

Why are irreversible hydrocolloids not suitable for crown and bridge, inlays, or onlays?

They do not produce fine details required for such procedures. (D) Signup and view all the answers

What is the primary reason for preferring individual sealed packets over bulk containers for irreversible hydrocolloids like Alginate impression materials?

Less chance for contamination during storage. (B) Signup and view all the answers

What role does CaSO4.2H2O play in the gelation process of irreversible hydrocolloids?

It is the main reaction ingredient that forms the gel. (A) Signup and view all the answers

What are the disadvantages of alginate impression material?

Tears easily, incompatible with gypsum materials (C) Signup and view all the answers

Why is tempering done in the manipulation of agar impression material?

To avoid burning the patient's oral tissues (B) Signup and view all the answers

What is the purpose of adding potassium sulfate to gypsum cast material?

To accelerate the setting of the material (C) Signup and view all the answers

At what temperature does the 'sol' state of agar impression material change to 'gel'?

37-45°C (A) Signup and view all the answers

What is the function of a conditioning unit in the manipulation of agar impression material?

To control and adjust the temperature of the material (B) Signup and view all the answers

What is the primary function of Na alginate or K alginate in irreversible hydrocolloids?

To form a sol with water that later reacts with calcium to form gel. (C) Signup and view all the answers

What happens to the 'gel' state of agar impression material when heated?

It changes back to 'sol' (B) Signup and view all the answers

What transformation does agar impression material undergo when cooling from 'sol' state?

It changes from 'sol' to 'gel' (A) Signup and view all the answers