Impression materials( Dental materials ) is of liquid or semi-solid nature when first mixed and placed in the mouth. It then sets to become an elastic solid (usually takes a few minutes depending upon the material), leaving an imprint of a person’s dentition and surrounding structures of the oral cavity. Academictask provides 2000+ basic and advanced level of dental materials MCQs with answers. In this section, we focus on all areas of MCQs on dental materials subject and cover all important topics of impression material like Amalgams, Dental Cements, Direct Filling Gold, Gypsum Products Mcqs, Impression Materials, Metallurgy, Physical Properties, Dental Ceramics & Miscellaneous, Restorative Resins –  and much more. All these topics are chosen from trusted and best reference books on dental and impression materials. These dental materials MCQs are also helpful for the preparation of interviews, entrance examinations, other competitive examinations, and certifications for all Experienced, Freshers and Students. Also, check MCQs on Pathology here.

41. Which of the following is NOT true of polymethyl methacrylate ?

A. Knoop hardness number 18 to 20
B. Tensile strength of 60 MPa
C. Density of 1.13 g/cm3
D. Modulus of elasticity of 3.4 GPa

42. Etchant preferred in gel from than in liquid form________________?

A. Better control over placement
B. Enhance and concentrate the action of acid
C. Helps in visualization while placement
D. None of the above

43. During polymerisation of acrylic resin, above what temperature benzoyl peroxide form freeradicals_______________?

A. 25°C
B. 37°C
C. 50°C
D. 60°C

44. Etching depth after 30 sec for orthodontic bracket with orthophosphoric acid is_________________?

A. 10 um – 20 um
B. 3 um – 9 um
C. 50 um – 110 um
D. 200 um – 250 um

45. The accepted polymer to monomer ratio for packing of polymethyl methacrylate resin is____________?

A. 3:1
B. 4:1
C. 10:1
D. 5:1

46. Residual monomer content of chemically activated resins is______________?

A. 0.2% to 0.5%
B. 2% to 5%
C. 0.3% to 0.5%
D. 2% to 5%

47. Dentin conditioner has the following function______________?

A. Removes smear layer
B. Increases surface energy of dentin
C. Forms a thin resin layer over exposed collagen fibrils
D. Helps in bonding with composite

48. The process wherein two or more chemically different monomers, each with some desirable property, can be combined to yield specific physical properties of a polymer is known as_____________?

A. Step-growth polymerization
B. Addition polymerization
C. Condensation polymerization
D. Copolymerization

49. Denture acrylics contain cross-linking agents mainly to improve their_____________?

A. Internal color
B. Tissue compability
C. Surface hardness
D. Craze resistance

50. Subsurface porosity is due to_____________?

A. Thermal changes
B. Thickness of the resin
C. Lack of temperature
D. Packing past the dough stage