1. strain hardening of a metal decreases its surface hardness proportional limit strength resistance to corrosion 2. the primary purpose of rinsing a set impression with a watery mix of dental stone to remove residual saliva from the surface of impression to retard shrinkage due to syneresis to increase the gel strength to prevent further gelation 3. gold alloys used for the fabrication of saddle bars and clasps are type IV type II type I type III 4. Copper content of single composition alloys 13-30% 30-40% 9-20% 0-6% 5. for best results when using an elastic impression material the prepared tooth should be very dry covered with a surface tension reducing agent or air dried covered thinly with a waer soluble lubricant free of surface moisture 6. In hot and dry environment, alginate shrinks by Syneresis Accretion Imbibition Hysteresis 7. Transformation toughening of zirconia occurs due to change in phase from: Cubic to tetragonal Monoclinic to tetragonal Austenitic to martensiti Tetragonal to monoclinic 8. Must commonly used coupling agent of composites:- Titanates Silicates Zirconate Organosilanes 9. Modulus of elasticity/tensile strength of brittle materials is measured by Cold bend test 3-point bend test Diametrical compresssion test Charpy test 10. What is the effect of addition of an accelerator or a retarder to a gypsum cast The compressive strength may increase or decrease depending upon the amount of the accelerator/retarder added The compressive strength increases No relation to compressive strength The compressive strength decreases 11. Cutting edge of surgical burs are made from martensite form rather than austenite form due to which of the following reason Martensite form is corrosion resistant Martensite form is very brittle Martensite form is hard Martensite form has less strength 12. Cavity Varnish is used with: Glass Ionomer Compomer Amalgam Composite 13. oxides of all of the following elements in noble metal alloys help in bonding to porcelain except iron tin nickel indium 14. Etching of feldspathic ceramic: HCL 35% Phosphoric acid HN03 HF acid 15. All of the following statements are true regarding glass ionomer restorations,except the best surface finish for a glass ionomer restoration is that obtained against a surface matrix glass ionomer is often the ideal material of choice for restoring root surface caries in patients with high caries activity glass ionomer adheres to mineralized tooth tissue glass ionomers are somewhat esthetic and polish much better than composites 16. Fluoride flux used in soldering works by Prevents formation of chromium oxide or dissolves already formed chromium oxide Weakens the solder joint Forms a protective film during soldering Preventing flow of solder to other areas 17. Which of the following property of amalgam is adversely affected by triturating with mechanical device Gloss of final mixture Less tarnish resistance Working time Hardness of final mixture 18. Which material is sensitive to Sulfur contamination from latex gloves: Agar Addition silicone Polyether Polysulfide 19. By product of setting reaction of condensation silicon: Ethyl alcohol Hydrogen Acetone Water 20. Best cementing medium for self retained all ceramic crown is Dual cure resin GIC Chemical cure resin RMGIC Loading … Question 1 of 20
