dental materials MCQs – Page 10

Practise focused dental materials questions with marked answers for exam preparation and subject revision.

dental materials Mcqs
181. Impression compound base_____________?
comments icon0

A. Crystalline structure

B. Low thermal conductivity

C. High fusion temperature

D. Formation of cross linkage with heating

182. Linear contraction of elostomeric impression with passage of time is highest in______________?
comments icon0

A. Polysulphide

B. Polyetner

C. Addition silicone

D. Condensation silicone
183. The linear solidification shrinkage of Type IV Ni-Cr based alloys is_______________?
comments icon0
A. 2.3%

B. 3%

C. 1.37%

D. 1.56%

184. Plaster of paris _____________?
comments icon0
A. Has porous and irregular crystals

B. Has a W / P of 0.2

C. Is a hamihydrate

D. Is wet calcined hemihydrate

185. Immediate pouring of impressions is most critical in_____________?
comments icon0
A. Condensation polysillicon

B. Polyether

C. Addition Polysilicon

D. A and B

186. The gold alloys used for casting contain at least. percent of precious metal according to ADA specification number 5________________?
comments icon0

A. 85

B. 75

C. 65

D. 55

187. Titanium casting is done_____________?
comments icon0

A. Under air pressure in nitrogen atmosphere

B. Under vacuum in argon atmosphere

C. In specially fabricated aluminium vanadium

D. Using CAD-CAM technique

188. Name the accelerator used in Zinc oxide eugenol paste______________?
comments icon0

A. Linseed oil

B. Olive oil

C. All of these

D. Zinc acetate
189. Silver plated dyes use an electrolytic bath of_______________?
comments icon0

A. Silver bromide

B. Silver iodide

C. Silver cyanide

D. Silver fluorides

190. The strength of the gypsum specimen when the water in excess of that required for the hydrate of the hemihydrate is left in the specimen is called____________?
comments icon0

A. Dry strength

B. Compressive strength

C. Green strength

D. Water strength

191. Indium in metal alloys_______________?
comments icon0

A. Improve bonding

B. Harden the metal ceramic Ag-Pd alloy

C. Both A and B

D. None of the above

192. Which of the following is true about Agar hydrocolloid impression material ?
comments icon0

A. Cannot register fine surface details

B. Solidfies between 50 70C

C. Facilitates fabrication of metal dyes

D. Liquefies between 71 100C
193. Tublulence of molten gold is due to _____________?
comments icon0

A. Improper venting

B. A and B

C. Impurities in gold

D. None of the above
194. Gap between true end of casting ring and wax pattern should be______________?
comments icon0

A. one inch

B. inch

C. inch

D. 3/8 inch

195. Vulcanization refers to the setting of__________________?
comments icon0

A. Zinc oxide-eugenol

B. Zinc Phosphate cement

C. Mercaptan impression material

D. Reversible hydrocolloid

196. Which of the following best describes the working time of impression material ?
comments icon0

A. After the start of appearing elastic properties of impression material

B. The time for start of mixing till just before the start of appearing elastic properties of impression material

C. Just after the start of appearing elastic properties of impression material

D. Loss of lusture of impression material

197. A highly polished surface on a metallic dental restoration aids considerably in the prevention of the____________?
comments icon0
A. Tarnish and corrosion

B. Warpage

C. Dimensional change

D. Thermal conductivity

198. The best way to remove a hydrocolloid impression from the patients mouth is____________?
comments icon0
A. Sudden jerking of the impression to prevent tearing

B. Supporting the impression along with the tray to prevent disengaging of the tray alone

C. Wetting the periphery of the impression with moist cotton to break the peripheral seal

D. Slight rocking of the impression to disengage it from the undercut

199. Which of the following cast gold alloys is used for fabricating partial denture frameworks______________?
comments icon0
A. Type IV Extra Hard

B. Type III Hard

C. Type I Soft

D. Type II Hard

200. The water powder ratio of alginate is______________?
comments icon0
A. 40 ml of water to 15 gms of powder

B. 100 ml of water to 60 gms of powder

C. 15 ml of water to 40 gms of powder

D. 40 ml of water to 40 gms of powder