1. Gutta percha, stearic acid and shellac are added to impression compound to: To improve softness at melting temperature Improve workability & plasticity To increase stifthess and hardness of the compound To prevent leaching out ofthermolabile components 2. dental impression compound is characterised by having a cross linkage reaction upon heating specific melting point relatively low thermal conductivity crystalline atomic structure 3. Nodule on the intaglio surface of a casting can be prevented by Wet the wax with water before investing Use of die spacer Use of a vibrator during investing of the wax pattern Spraying a surfactant on the wax pattern before investing 4. type IV gold casting alloys are used for fabricating 3/4 crowns inlays removable partial denture frameworks short span bridges 5. exposure of a stone cast to tap water should be minimised because the cast will be weakened dimensional achange will occur in th ecast the surface of the cast will acquire a chalky appearance eroding of the cast will result 6. Which of the following statements is not true regarding glass ionomer cements? high solubility after initial setting good thermal insulator release fluoride thermal expansion similar to tooth 7. Palladium and platinum are added to base metal alloys to: As grain refiners Reduce brittleness Act as scavenger Impart color 8. 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 hard Martensite form is very brittle Martensite form has less strength 9. Principle hardener in gold alloy is Copper Palladium Silver Zinc 10. In orthodontic stainless steel wire which of the following is used to reduce hardness? Chromium Cobalt Silicone Carbon 11. Which of the following will produce the most rigid restoration for framework of same dimension Partial denture casting gold in hardened condition Cobalt chrome alloys Wrought alloy Palladium alloys 12. The chamelon effect has been portrayed by which of the ceramic restorations Dicor Cerestore In ceram Cerec 13. Which of the following statements is not true regarding creep? undertrituration tends to increase the creep rate creep is a process that happens over time creep gradually increases the marginal integrity of an amalgam restoration increasing the condensation pressure decreases the creep rate 14. the penetration of the fissure sealant into the fissures is not influenced by the wettability of the enamel must occur before the polymerisation of the material is the result of a chemical bond between the sealant and enamel is independent of the chemical composition of the enamel 15. When using which impression material can you delay pouring up of the model for up to one week? reversible hydrocolloid Polyether poly vinyl siloxane polysulfide 16. a thinner mix of gypsum bondeded investment will result in produce a smoother casting increases thermal expansion decrease setting expansion increases setting expansion 17. Following is added to zinc polycarboxylate to improve its manageability: Aluminium oxide Magnesium oxide Strontium fluoride Stannous fluoride 18. for a successful metal ceramic restoration both the metal and porcelain must have closely matched coefficient of thermal expansion compressive strength specific gravity solidification shrinkage 19. all of the following processes can be performed at room temp except work hardening strain hardening cold working forging 20. highest water solubility is seen in zinc silicophosphate zinc oxide eugenol zinc polycarboxylate zinc phosphate Loading … Question 1 of 20
