ACCURACY IS GUARANTEED
Dental Materials NBDHE Questions with Detailed
Verified Answers for Accuracy
Adhesion
✓✓ The chemical attraction between unlike molecules
Cohesion
✓✓ The chemical attraction between like molecules
Coefficient of thermal expansion
✓✓ An index which indicated how one material reacts to
temperature extremes in relation to another
Compressive Strength
✓✓ The force at which a material breaks under pressure
Creep
✓✓ Slow dimensional change caused by compression
Ductility
✓✓ The ability to undergo change of form without breaking
Elasticity
✓✓ Material's ability to recover its initial shape after
undergoing a force
, ACCURACY IS GUARANTEED
Galvanism
✓✓ An electrical current generated by dissimilar metals in an
acidic environment
Gelation
✓✓ The process of gelling (solidification by cold)
Imbibition
✓✓ Absorption of a solvent by a gel
Malleability
✓✓ A material's capacity to be shaped by force or pressure
Microleakage (percolation)
✓✓ Passage of oral fluids/bacteria into and out of tooth
structure due to marginal gap or failure of marginal
(restorative) seal
Polymerization
✓✓ The linking, branching, or cross-linking of smaller
molecules
Proportional limit
✓✓ The force at which a material cannot return to its original
shape
, ACCURACY IS GUARANTEED
Syneresis
✓✓ Contraction of a gel due to the loss of a solvent
Tensile strength
✓✓ The force needed to stretch a material to the point of
fracture
Viscocity
✓✓ Resistance to flow
Amalgam
✓✓ By definition: an alloy of mercury
In dentistry: an alloy of mercury with silver, copper, tin, and
zinc
Silver, a base metal, susceptible to corrosion
Copper added to minimize the corrosion (gamma II phase
eliminated)
Amalgam desirable features
✓✓ Durable
Similar compressive strength to enamel
Relatively inexpensive
Amalgam undesirable features
Dental Materials NBDHE Questions with Detailed
Verified Answers for Accuracy
Adhesion
✓✓ The chemical attraction between unlike molecules
Cohesion
✓✓ The chemical attraction between like molecules
Coefficient of thermal expansion
✓✓ An index which indicated how one material reacts to
temperature extremes in relation to another
Compressive Strength
✓✓ The force at which a material breaks under pressure
Creep
✓✓ Slow dimensional change caused by compression
Ductility
✓✓ The ability to undergo change of form without breaking
Elasticity
✓✓ Material's ability to recover its initial shape after
undergoing a force
, ACCURACY IS GUARANTEED
Galvanism
✓✓ An electrical current generated by dissimilar metals in an
acidic environment
Gelation
✓✓ The process of gelling (solidification by cold)
Imbibition
✓✓ Absorption of a solvent by a gel
Malleability
✓✓ A material's capacity to be shaped by force or pressure
Microleakage (percolation)
✓✓ Passage of oral fluids/bacteria into and out of tooth
structure due to marginal gap or failure of marginal
(restorative) seal
Polymerization
✓✓ The linking, branching, or cross-linking of smaller
molecules
Proportional limit
✓✓ The force at which a material cannot return to its original
shape
, ACCURACY IS GUARANTEED
Syneresis
✓✓ Contraction of a gel due to the loss of a solvent
Tensile strength
✓✓ The force needed to stretch a material to the point of
fracture
Viscocity
✓✓ Resistance to flow
Amalgam
✓✓ By definition: an alloy of mercury
In dentistry: an alloy of mercury with silver, copper, tin, and
zinc
Silver, a base metal, susceptible to corrosion
Copper added to minimize the corrosion (gamma II phase
eliminated)
Amalgam desirable features
✓✓ Durable
Similar compressive strength to enamel
Relatively inexpensive
Amalgam undesirable features
