Dental Materials

the acid used most commonly to etch tooth structure for bonding procedures is
A. phosphoric
B. hydrofluoric
C. hydrochloric
D. citric

all of the following statements about bonding to enamel are true except one.
A. more reliable bond than the bond to dentin
B. achieved by micromechanical retention
C. achieved by resin tags penetrating porosities in the enamel and by locking into surface roughness
D. achieved by chemical bonding

bonding to dentin
A. is stronger when the dentin is well dried after etching
B. is best on dentin that has been etched with 35% phosphoric acid for 30 sec
C. is inhibited by formation of the hybrid layer
D. is best accomplished when the dentin is kept moist after etching

all of the following statements about resin bonding agents are true except one
A. they are dissolved in solvents that allow them to penetrate the water on the moist dentin
B. they chemically bond to the dentin
C. they chemically bond to composite resin
D. they seal the dentin by penetrating into etched dentin surfaces and tubules

self-etching bonding agents
A. use acidic primers to etch the tooth structure
B. require rinsing after etching
C. use 35% phosphoric acid as the etchant
d generally etch enamel equally as well as dentin

total etch bonding systems
A. may result in tooth sensitivity caused by over drying or over etching
B. do not require a separate etching and rinsing step
C. do not provide a good etch to uncut enamel
D. do not require drying of the primer

with the total etch system when bonding to dentin one of the following statements is true.
A. the surface of prepared dentin should have visible water droplets
B. the surface of the etched, washed and dried dentin should be glistening
C. once you have dried the etched surface bonding is hopeless
D. the dentin surface should be thoroughly dried after etching and rinsing

dentin sensitivity can be caused by
A. pressure changes in the column of fluid within the dentinal tubules
B. stimulation of odontoblastic processes within the dentinal tubules
C. open dentinal tubules
D. over etching or over drying of the dentin
E. all of the above

the smear layer
A. is left on the dentin when bonding with the total etch technique
B. is a tenacious layer of cut too th debris on the surface of enamel and dentin
C. is easily removed by rinsing with water
D. is necessary for good boding

all of the following statements about bonding to repair fractured porcelain on a crown are true except one
A. silane is applied after etching to enhance the bond of adhesive resins to porcelain
B. composite resin is usually used to restore the fractured portion
C. the surface is cleaned and roughened
D. 10% phosphoric acid is used to etching the porcelain

which one of the following does NOT interfere with the formation of a good bond?
A. moist dentin after rinsing etchant off and lightly drying
B. saliva on the etched enamel or dentin
C. oil lubricant from the handpiece
D. flavoring agent in prophy paste

which one of the following is true regarding the bonding of amalgam to a cavity preparation
A. freshly mixed amalgam is condensed onto unset bonding resin
B. the bonding resin should be light cured
C. only the enamel is acid etched
D. wax is rubbed on inside of the matrix band to keep the band from being glued to the tooth by bonding resin

when endodontic posts are bonded into root canals the boding agent should not be
A. dual curing
B. light curing
C. applied in a thin layer
D. self curing

all of the following are correct steps for bonding orthodontic brackets except one
A. the tooth surface is cleaned with pumice
B. the enamel is rinsed and left slightly moist
C. the enamel is etched with 35% phosphoric acid for approximately 30 seconds
D. the resin adhesive is often used to bond the bracket

when bonding composite resin to metal that is exposed after the overlying porcelain has fractured which one of the following is FALSE?
A. bonding agents are not needed because the composite resin sticks to the metal
B. retention of the metal is enhanced by roughening the surface with a coarse diamond bur, by sandblasting, by electrochemically etching or by tin plating
C. light curing materials can be used
D. a opaque resin is applied before the composite resin to mask the metal and prevent a gray color from showing through the slightly translucent composite resin