Free Properties of Dental Materials MCQs with Answers

• A. The elastic limit
• B. The yield strength
• C. The proportional limit
• D. Modulus of elasticity

Explanation: The proportional limit is the greatest stress at which stress remains directly proportional to strain, giving a straight-line portion of…

• A. The stress at the proportional limit
• B. The strain at the proportional limit
• C. None of the above
• D. The stress/strain ratio within the proportional limit

Explanation: Within the proportional limit, modulus of elasticity equals stress divided by strain, represented by the slope of the straight portion of…

• A. A deformation resulting from an applied load
• B. An applied load or force
• C. An external force opposing an applied load
• D. An internal force opposing an applied load

Explanation: Strain is the deformation produced by an applied load, expressed relative to the material’s original dimension.

• A. High adherend wetting
• B. High contact angle
• C. Low contact angle
• D. High flow

Explanation: Good adhesive wetting requires a low contact angle, because the adhesive must spread over the adherend; high flow also assists spreading.

• A. Spherical indenter
• B. Steel ball indentation
• C. Rhomboid shaped indenter
• D. 136-degree diamond pyramid

Explanation: The Vickers test uses a diamond pyramid indenter with a square base and an included angle of 136°.

• A. Brittleness
• B. Ductility
• C. Malleability
• D. Resilient

Explanation: Brittle materials tolerate high compressive stress but fail with little tensile deformation.

• A. Elastic Behaviour
• B. Viscoelastic Behaviour
• C. Plastic Behaviour
• D. All of the above

Explanation: The Maxwell and Voigt models use combinations of springs and dashpots to represent time-dependent viscoelastic behaviour.

• A. Acrylic
• B. Carbon
• C. Graphite
• D. Porcelain

Explanation: Graphite conducts electricity because its layered carbon atoms contain delocalised electrons that can move through the layers.

• A. Proportional limit
• B. Brittleness
• C. Young's modulus
• D. Toughness

Explanation: Toughness is the energy a material absorbs through elastic and plastic deformation before fracturing, represented by the total area under…

• A. Pure gold
• B. Amalgam
• C. Composite
• D. Prcelain

Explanation: Enamel has a Knoop hardness value closest to porcelain among these choices.

• A. Spring back
• B. permanent deformation
• C. Fracture of the wire
• D. Increase in stiffness

Explanation: A load below the elastic limit produces only elastic deformation, so the wire returns toward its original shape when the load is removed…

• A. Viscoelastic
• B. Pseudoplastic
• C. Newtonian
• D. Plastic

Explanation: A Newtonian fluid has constant viscosity, so its resistance to flow remains unchanged when the strain rate changes.

• A. Brinnel
• B. Rockwell
• C. Shore-A
• D. Knoop

Explanation: The Knoop test uses a small diamond indenter and low loads, so it is designed for microhardness testing of thin sections and small areas.

• A. Creep
• B. Resillience
• C. Elastic limit
• D. Ultimate strength

Explanation: Creep is a time-dependent increase in strain under a sustained load, often becoming important in dental materials exposed to prolonged…

• A. The consistency of material when mixing
• B. Continued change of the material under a given load
• C. The homogencity of gypsum products
• D. Dimensional change of the material during settings

Explanation: Flow is the continued deformation of a material while a load is maintained, especially when the material behaves plastically or…

• A. Modulus of elasticity
• B. Tensile strength
• C. Young's modulus
• D. Compressive strength

Explanation: A base must resist the compressive forces transmitted through the restoration during occlusion, so compressive strength is the key…

• A. Elastic limit / Elastic strain
• B. Resilience
• C. Hardness
• D. Fatigue resistance

Explanation: The elastic limit is the greatest stress a material can withstand without permanent deformation, which directly matches the statement.

• A. Yield strength
• B. Hardness
• C. Modulus of elasticity
• D. None of the above

Explanation: Hardness is the resistance of a material surface to indentation, scratching and abrasion.

• A. Longitudinal compressive strength
• B. Stress after rupture
• C. Stress before rupture
• D. Horizontal compressive strength

Explanation: Ultimate tensile strength is the greatest tensile stress a material withstands before fracture or rupture.

• A. Brittleness
• B. Toughness
• C. Tensile strength
• D. Resilience

Explanation: Resilience describes the ability to absorb elastic energy and recover the original shape when the load is removed, which explains the…