Karnatak University 2009 Bachelor
Thursday, 24 January 2013 09:15Web
Page 2 of 2
11. E-Z gold is a kind of
a) gold foil
b) crystalline gold
c) powdered gold
d) fibrous gold
12. 24 hour compressive strength is highest for
a) zinc phosphate cement
b) GIC
c) polycarboxylate cement
d) zinc-oxide eugenol cement
13. Material having coefficient of thermal expansion similar to that of the tooth enamel
a) composite
b) amalgam
c) type II GIC
d) direct filling gold
14. Strength in gypsum investment is given by
a) quartz
b) dental stone
c) silica
d) tridymite and cristoballite together
15. Component of inlay wax that contributes more to the glossiness of the wax surface is
a) paraffin wax
b) gum dammar
c) carnauba wax
d) candelilla wax
*1725* -5- 1725
PART – B
(Prosthodontics)
1
Time : one /2 Hours Marks : 50
I. describe soldering and welding. Enumerate the desirable qualities of an ideal solder.
Write in detail about investment soldering and free hand soldering techniques. 10
II. Write the composition and setting reaction of irreversible hydrocolloid impression material. provide the causes and remedies for various kinds of failure encountered
with the use of irreversible hydrocolloid impression material. 10
III. Write short notes on : 15
a) Viscosity.
b) Galvanic corrosion.
c) Separating medium.
IV. Multiple option ques. : 15
1) Increasing the Water-Powder ratio of dental stone would
a) Increase the setting expansion
b) Increase the 1-Hr compressive strength
c) Lengthen the setting time
d) Decrease the amount of excess water used to mix the material
2) The setting time of zinc oxide eugenol impression paste can be prolonged by
a) Mixing for a longer time
b) Adding chemical modifier, zinc acetate
c) Decreasing the amount of base paste
d) Cooling the glass slab and spatula not beneath the dew point
1725 -6- *1725*
3) The main purpose of adding butadiene styrene rubber to acrylic resin is to increase its
a) Impact strength
b) Compressive strength
c) Tensile strength
d) Shear strength
4) Cristobalite is a high expansion form of
a) SiO2 b) Al2O3 c) K2O d) Na2O
5) The yield stress of metals can be improved by
a) Chemical tempering
b) Transformation toughening
c) Thermal tempering
d) Work hardening
6) Crazing of dentures occurs as a outcome of
a) Relaxation of internal surface stresses
b) Lack of conduction of heat from inside to outside
c) Lack of adequate pressure
d) Leaching out of the plasticizer
7) Agar hydrocolloid gel should be liquefied by heating at
a) 37° C b) 45° C c) 65° C d) 100° C
8) The boiling point of methyl methacrylate monomer is
a) 100.8° C b) 180.1° C c) 108.0° C d) 108.8° C
9) Hardness of which of the subsequent abrasives is maximum ?
a) Sand b) Emery
c) Boron carbide d) Silicon carbide
*1725* -7- 1725
10) What is a wrought metal ?
a) When metal is worked in cold state
b) When metal is heated and then cooled
c) When copper is added to a metal
d) When more than 2 metals are mixed in molten state
11) Siliconized alginates have better
a) Impact strength b) Transverse strength
c) Tear strength d) Fatigue strength
12) Phenol and formaldehyde are polymerized to a resulting product known as
a) Vulcanite b) Bakelite
c) Cryolite d) Cellulose nitrate
13) In which of the subsequent hardness tests, hardness is measured as the depth of penetration
a) Brinell b) Rockwell
c) Vickers d) Knoop
14) The binder used in gypsum bonded investments is
a) Sodium phosphate
b) Ethyl silicate
c) Calcium sulfate alpha hemihydrate
d) Ammonium phosphate
15) Hardness of elastomers is measured by using
a) Oscillating rheometer
b) Shore a durometer
c) Vicat penetrometer
d) Gillmore needle
———————
PDF to Word
Earning: Approval pending. |