1. Green shrinkage seen in : It is seen in all types of investments Ethyl Silicate bonded investment Phosphate Bonded Investment Gypsum Bonded investment 2. Bond strength required to counteract the effect of polymerization shrinkage in composite resins: 56 MPa 21 MPa 17 MPa 7 MPa 3. Loss of colour stability in self polymerizing resins is due to degradation of: Tertiary amine Polymethyl methacrylate Benzoyl peroxide initiator Hydroquinone 4. In mixing dental stone, why should the powder be sprinkled onto the water in the bowl? this is not recommended; the water should be added to the powder the addition of powder prevents the mix from becoming exothermic the powder is added to the water to avoid using more than one bowl this process results in better powder mixing and reduced chance for air bubbles 5. Disinfection of alginate impressions when immersion method is used should not exceed 5m 20m 10m 30m 6. Maximum flow of Type I inlay wax at 45 degrees: 70percent 2 percent 3percent 10percent 7. maximum shrinkage of firing of ceramic occurs during which stage low bisque high bisque medium bisque none of the above 8. an advantage of rubber base impression material over reversible hydrocolloid material is that rubber base impression material will displace soft tissue is significantly more accurate requires less armamentarium is more accurate if saliva mucus or blood is present 9. diamond particle size of 125-150 um is catagorised as coarse medium fine extrafine 10. Primer which etches and primes dentin is known as: Two step system Self etching primer Self etch adhesive Auto etch adhesive 11. Phosphate bonded investment is made carbon free: To prevent staining of ceramic To produce smooth casting To prevent brittleness of alloy For easier divesting of investmen 12. The ratio of transverse contraction strain to longitudinal extension strain in the direction of stretching force is known as Compressive stress Shear stress Tensile stress Poissons ratio 13. Fluoride flux used in soldering works by Prevents formation of chromium oxide or dissolves already formed chromium oxide Forms a protective film during soldering Weakens the solder joint Preventing flow of solder to other areas 14. Which of the following best describes “strain hardening” or “work hardening”? softening a metal by controlled heating and cooling softening a metal at room temperature hardening (or deformation) of a metal at room temperature hardening (or deformation) of a metal at a very high temperature 15. a cermet is a combination of feldspar and quartz conventional and aluminous ceramic powders the powders of polycarboxylate and composite resin cements silver amalgam powder and glass ionomer powder 16. Purpose of reservior is to Help in removal of wax Prevent removal of molten metal Gives smooth polished surface Prevent localised shrinkage porosity 17. In orthodontic stainless steel wire, content of carbon is 1-1.2 percent 12-20 percent 6-8 percent 0.6 -0.8 percent 18. Which material has least shelf life Condensation silicone Addition silicone Polysulphide Polyether 19. Which property of composites is most affected by the size and number of fillers: Thermal expansion Thermal contraction Polymerization shrinkage Water sorption 20. carnauba wax is added to basic paraffin wax to ensure uniformity of batches decrease flow at mouth temp improve the smoothness in molding render it resistant to cracking and flaking Loading … Question 1 of 20
