dental materials MCQs – Page 27

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

dental materials Mcqs
521. Best marginal seal is provided by____________?
comments icon0

A. Zinc phosphate

B. Zinc oxide eugenol

C. Gutta-percha

D. Resin

522. When Gold fused with porcelain is fired at very high temperature greenish discoloration of cervical margin is due to________________?
comments icon0

A. Disintegration of opaque layer

B. High firing temperature

C. Presence of copper

D. Formation of excess oxides

523. Which of the following releases single wavelength of energy ?
comments icon0

A. QTH

B. PAC

C. Argon lasers

D. LED

524. Which of the following cements bonds to tooth structure, which has an anticariogenic effect, has a degree of translucency and does not irritate the pulp ?
comments icon0

A. Resin cement

B. Silicate cement

C. Polycarboxylate cement

D. Glass ionomer cement
525. The first porcelain tooth material was introduced by______________?
comments icon0
A. DeChemant

B. Plateau

C. Ash

D. McClean

526. Mercury is toxic because it_____________?
comments icon0
A. Binds to sulfhydryl groups

B. Inhibits hemoglobin synthesis, producing anemia

C. Complexes with hemoglobinto form methemoglobin

D. Inhibits anaerobic glycolysis

527. The higher the Hg alloy ratio in dental amalgam________________?
comments icon0

A. More gamma 1 phase formed

B. Lower the creep value

C. Higher the strength

D. More matrix matrial formed
528. Once triturated, the Dental amalgam should be condensed with in_____________?
comments icon0

A. 5 minutes

B. 3 minutes

C. 15 minutes

D. 6 minutes

529. The principal constituent of set silicate cement matrix is_______________?
comments icon0
A. Hydrated Aluminium phosphate crystal, CAF2 alluminosiliate gel

B. Hydrated Aluminium Phosphate with calcium fluoride

C. Hydrate Aluminosilicate gel

D. Hydrated Aluminium phosphate

530. High copper amalgam can be produced_____________?
comments icon0

A. From smooth atomized particles

B. From irregular and spherical particles

C. From lathe cut particles

D. From traditional alloy particles

531. What is the working time of amalgam?
comments icon0

A. Five to six minutes

B. Seven to eight minutes

C. One to two minutes

D. Three to four minutes
532. Glass ionomer cements are composed of______________?
comments icon0

A. Alumino silicate powder and phosphoric acid

B. Zinc oxide powder and polyacrylate liquid

C. Aluminosillicate powder and polyacrylate

D. Zinc oxide powder and phosphoric acid

533. Over-trituration of silver alloy and mercury_______________?
comments icon0

A. Decreases creep

B. Gives al dull and crumbly amalgam

C. Reduces contraction

D. Increases the strength of lathe cut alloy but reduces the strength of spherical alloy amalgam
534. White gold alloy predominantly is______________?
comments icon0

A. Gold with silver

B. Gold with much of chromium

C. Gold added with palladium

D. Gold added with calcium

535. The malleting force is directed______________?
comments icon0

A. None of the above

B. Parallel to long axis of crown

C. Perpendicular to the walls

D. 45 to the wall
536. Torsional force is_______________?
comments icon0
A. Shear

B. Tensile force

C. Transverse bending force

D. Compression

537. The setting time of ZnPO4 cement can be retarded by_____________?
comments icon0
A. slower addition of powder to liquid

B. mixing powder to liquid, checked by water

C. faster addition of powder to liquid

D. mixing more powder to the liquid

538. Silicate cement is indicated in________________?
comments icon0
A. Patients with high caries index

B. In the restoration of posterior tooth

C. Mouth breathers

D. None of the above

539. The logical explanation for the unique anticariogenic property of most silicate cements is______________?
comments icon0

A. That beryllium flux is used in silicates

B. The reduction in enamel solubility due to fluoride uptake by enamel

C. Due to the high silica content

D. That silicates show very little leakage at the margins of the restoration

540. The best tissue tolerated material for crown and bridge_______________?
comments icon0

A. Highly polished porcelain

B. Highly glazed porcelain

C. Highly polished acrylic

D. Highly polished metal