A drop of water on a Popsicle is an example of:
Poor wetting (low contact angle)
Good wetting (high contact angle)
Good wetting (low contact angle)
Poor wetting (high contact angle)
The tightening of a guitar string is an example of which of the following stresses?
Compression
Torsion
Shear
Tension
The modulus of elasticity is an indication of what property of a material?
Resilience
Strength
Stiffness
Cooled Materials will contract, and heated materials will expand. A measurement of this change in volume in relation to change in temperature is called the coefficient of thermal expansion.
First statement is true; second statement is false.
First statement is false; second statement is true.
Both statements are true.
Both statements are false.
When a stress is induced in a material that is greater than the materials yield strength the stress is ____ proportional to the strain in the material does not return to its original shape.
Always
No longer
Equally
None of the above
Which formula defines the modulus elasticity?
Stress/strain
Stress2/strain
Strain/stress
2 x stress/strain
An example of a physical property is:
Density
Setting reaction
A twisting force is termed:
The ability of a material to dissolve in liquid is termed:
Viscosity
Water sorption
Solubility
Wetting
Elasticity is an example of which of the following properties?
Physical
Mechanical
Chemical
Biologic
The rate of heat flow through the material is referred to as:
Heat of fusion
Coefficient of thermal expansion
Heat capacity
Thermal conductivity
Jennifer is a practicing hygienist who goes to a nearby restaurant each day for lunch. She often orders a cola with ice and a bowl of homemade soup. As she eats and drinks, her composite restorations (tooth colored) and tooth structure are expanding and contracting at different rates. This change in volume or length of the materials due to the hot food and cold drink is referred to as:
Fingernail polish remover has solvent properties as it will remove the polish from our fingernails. Another property polish remover has it is the tendency to evaporate. Fingernail polish remover can be said to have:
A higher vapor pressure
A low vapor pressure
No vapor pressure
And intermittent paper pressure
Match the properties with the procedure or situations. ____ is the force used to condense and amalgam in a preparation. A hardened cement having low _____ can firmly hold a patients gold crown in place for years in a wet environment. ____ is the term given to the increase of stress around defects within an object.
Solubility, compression, Viscosity
Compression, solubility, stress concentration
Stress concentration, compression, solubility
Compression, viscosity, stress concentration
Postage stamps are now self adhesive. The paper (stamp) is referred to as the ____ and the sticky material on the back of the stamp is termed the ____.
Adherend; adhesive
Adhesive; adherend
Adhesive; bonding agent
Adherents; biofilm
Kristen has orthodontic appliances, commonly known as braces. These include metal brackets directly bonded to the facial surfaces with the bonding material. One bracket breaks off, and the failure occurs within the bonding material. This type of failure is considered to be:
Adhesive
Adherend
Cohesive
Macromechanical
Orthophosphoric acid (enamel etchant) is commonly used in a ____ concentration
27%
30%
37%
47%
Why do primary teeth need to be etched longer than permanent teeth?
Compensates for potential behavioral management problems
The enamel is denser on primary teeth
The enamel rods are more regularly arranged than on permanent teeth
The enamel rods are less regularly arranged then on permanent teeth
Dentinal bonding systems function by way of:
Micromechanical bonding in secondary atomic bonds
Macromechanical bonding and secondary atomic bonds
Micromechanical bonding and primary atomic bonds
Macromechanical bonding and primary atomic bonding
The Dentin debris that is created when Dentin is cut or prepared by dental instruments is called:
Adhesive layer
Smear layer
Primer layer
Chelating agent
The use of bonding in dentistry serves all of the following functions except:
Reduction of recurrent caries
Retention of color in the restoration
Reduction of microleakage
Retention of restorations
An adhesive mechanism of a dentinal bonding system is a hybrid layer. It is composed of:
The smear layer and resin
Dentin primer and decalcified enamel
Resin and decalcified enamel
Resin and decalcified Dentin
The following are all historical fallacies about dentinal bonding except one. Which one is the exception?
composites irritate the pulp
Dentin should not be etched
The smear layer is dentinal debris
The smear layer should be left to protect the pulp
Which of the following cements are available in a single dose capsule much like that of silver amalgam filling material?
Polycarboxylate
Silicate
ZOE
Glass ionomer
Zinc phosphate
To dental cement that are used for caries control are:
ZOE and zinc phosphate
ZOE and polycarboxylate
Zinc phosphate in glass ionomer
Glass ionomer and polycarboxylate
Glass ionomer and ZOE
All of the following are true for ZOE except:
It releases fluoride
It lacks strength
It is an obtundent material
It protects the pulp
Which of the following cement is most soluble?
One glass ionomer is next to slowly, the resulting mix is:
Thin
Thick
Lumpy
Granular
Cement are ____ soluble than the overlying restoration.
More
Less
During mixing, which of the following cements should use as much of the area on the slab as possible to reduce the exothermic reaction?
Which of the following dental materials promotes the formation of secondary Dentin?
Composite cements
Silicate Cements
Calcium hydroxide
Temporary cements
Which of the following is a common additive to glass powder, reduces melting temperature, and improve the flow of molten glass?
Quartz
Fluoride
Oxides
The cement of choice for meeting ceramic restorations to tooth structure is
Composite
The disadvantage, or drawback, of using polycarboxylate cement is:
Lack of strength
Ability to bond to tooth structure
Biocompatibility
Lack of sufficient clinical data for long-term use
ZOE maybe used for the following: temporary restorations, intermediate pieces, permanent restorations, looting temporary crowns, looting permanent crowns
Temporary restorations, intermediate bases, permanent restorations
Temporary restoration and intermediate bases
Temporary restorations, intermediate bases, looting temporary crowns