In reversible hydrocolloid the property by which the transformation from sol to gel and gel to sol is a function of the_____________?

Related Mcqs:

1. Sol – gel transformation is seen in________________?

   A. Impression plaster
   B. Hydrocolloids
   C. Elastomer
   D. Impression compound

2. A technique of combining reversible and irreversible hydrocolloid that could bond to irreversible hydrocolloid is known as________________?

   A. Injecting technique
   B. Laminate technique
   C. Immersion technique
   D. Tempering technique

3. Hysteresis in a hydrocolloid gel is______________?

   A. Moisture absorption
   B. Temperature lag between gelation and liquefaction temperature
   C. Phenomenon of conversion of gel into sol
   D. All of the above

4. Syneresis seen in hydrocolloid gel is______________?

   A. Seen as water loss
   B. Water absorption
   C. Shrinkage
   D. Gelation

5. The basic constituent of reversible hydrocolloid impression material is________________?

   A. Agar
   B. Alginic acid
   C. Gelatin
   D. alginate

6. Dimensional stability of hydrocolloid impressions may be achieved by_________________?

   A. Using less water powder ratio
   B. Storing the impression under water
   C. Prolonged manipulation
   D. Using humidor

7. Hydrocolloid material, show all except______________?

   A. Hysterisis
   B. Imbibition
   C. Recrytallisation
   D. Syneresis

8. Which one of the following increase the strength and reduce viscosity of agar hydrocolloid impression material_____________?

   A. Borax
   B. Water
   C. Sulfates
   D. Carbonates

9. Which of the following is true about Agar hydrocolloid impression material ?

   A. Liquefies between 71 – 100°C
   B. Solidfies between 50 – 70°C
   C. Facilitates fabrication of metal dyes
   D. Cannot register fine surface details

10. The best way to remove a hydrocolloid impression from the patient’s mouth is____________?

    A. Slight rocking of the impression to disengage it from the undercut
    B. Wetting the periphery of the impression with moist cotton to break the peripheral seal
    C. Sudden jerking of the impression to prevent tearing
    D. Supporting the impression along with the tray to prevent disengaging of the tray alone