NBDE Part II - Operative Dentistry
UPDATED ACTUAL Exam Questions and
CORRECT Answers
pH that enamel starts to demineralize - CORRECT ANSWER - 5.5 (critical pH)
How do cells first attach - dextran or lextran? - CORRECT ANSWER - dextran
. S. Mutans is involved in converting sucrose to dextran using enzyme Glucosyltransferase.
What helps in carious progression but it is not the primary initiator for caries? - CORRECT
ANSWER - LACTOBACILLUS
Best clinical determinant of root caries?
a) sensitivity to cold
b) sensitivity to sweets
c) soft spot on tooth - visual and tactile methods are used to detect caries - CORRECT
ANSWER - c) soft spot on tooth - visual and tactile methods are used to detect caries
T/F: remineralized teeth are stronger than regular enamel. - CORRECT ANSWER - TRUE
reminieralized enamel is darker, harder, more resistant
For a lesion in enamel that has remineralized, what is most likely true?
a) The enamel has smaller hydroxyapatite crystals than the surrounding enamel
b) The remineralized enamel is SOFTER then the surrounding enamel
,c) The remineralized enamel is DARKER than the surrounding enamel
d) The remineralized enamel is ROUGH and cavitated - CORRECT ANSWER - c) The
remineralized enamel is DARKER than the surrounding enamel
Most inter proximal caries lesion happens where? - CORRECT ANSWER - Just
under/below contact
What tooth is most likely to have occlusal caries? - CORRECT ANSWER - Mandibular
molar
40 y/o patient with all 32 teeth. No cavities. Has stain and catch in pit of molar. What do you do?
a) watch and observe
b) sealant
c) composite - CORRECT ANSWER - a) watch and observe
DMFT (decayed, missing, filled teeth) - CORRECT ANSWER - Quantifies how the
PERMANENT dentition has been affected by dental caries
no 3rd molars
DMFS (decayed, missing, filled surfaces) - CORRECT ANSWER - A more detailed index
than DMFT as it quantifies how each tooth surface has been affected by caries
3rd molars included
DEFT (decayed, extracted, or filled teeth) - CORRECT ANSWER - Quantifies how the
PRIMARY dentition has been affected by dental caries
, DEFS (decayed, extracted, or filled surfaces) - CORRECT ANSWER - Quantifies how
each surface of the primary dentition has been affected by dental caries
Which population has the most number of UNRESTORED caries? - CORRECT
ANSWER - Blacks
Burs used for smoothing preps?
a) more flutes and shallow
b) more flutes and deeper
c) less flutes and shallow
d) less flutes and deeper - CORRECT ANSWER - a) More FLUTES and SHALLOW (red
burs)
Bur used that converges F and L walls?
a) 245
b) 7901
c) 169 - CORRECT ANSWER - a) 245
What bur do you use to SHAPE convergent walls for amalgam? - CORRECT ANSWER -
169
Which high speed bur gives a smoother surface? - CORRECT ANSWER - Plain cut
fissure bur
best cross cut fissure have a higher cutting efficiency
Bur used for polishing - CORRECT ANSWER - STEEL
UPDATED ACTUAL Exam Questions and
CORRECT Answers
pH that enamel starts to demineralize - CORRECT ANSWER - 5.5 (critical pH)
How do cells first attach - dextran or lextran? - CORRECT ANSWER - dextran
. S. Mutans is involved in converting sucrose to dextran using enzyme Glucosyltransferase.
What helps in carious progression but it is not the primary initiator for caries? - CORRECT
ANSWER - LACTOBACILLUS
Best clinical determinant of root caries?
a) sensitivity to cold
b) sensitivity to sweets
c) soft spot on tooth - visual and tactile methods are used to detect caries - CORRECT
ANSWER - c) soft spot on tooth - visual and tactile methods are used to detect caries
T/F: remineralized teeth are stronger than regular enamel. - CORRECT ANSWER - TRUE
reminieralized enamel is darker, harder, more resistant
For a lesion in enamel that has remineralized, what is most likely true?
a) The enamel has smaller hydroxyapatite crystals than the surrounding enamel
b) The remineralized enamel is SOFTER then the surrounding enamel
,c) The remineralized enamel is DARKER than the surrounding enamel
d) The remineralized enamel is ROUGH and cavitated - CORRECT ANSWER - c) The
remineralized enamel is DARKER than the surrounding enamel
Most inter proximal caries lesion happens where? - CORRECT ANSWER - Just
under/below contact
What tooth is most likely to have occlusal caries? - CORRECT ANSWER - Mandibular
molar
40 y/o patient with all 32 teeth. No cavities. Has stain and catch in pit of molar. What do you do?
a) watch and observe
b) sealant
c) composite - CORRECT ANSWER - a) watch and observe
DMFT (decayed, missing, filled teeth) - CORRECT ANSWER - Quantifies how the
PERMANENT dentition has been affected by dental caries
no 3rd molars
DMFS (decayed, missing, filled surfaces) - CORRECT ANSWER - A more detailed index
than DMFT as it quantifies how each tooth surface has been affected by caries
3rd molars included
DEFT (decayed, extracted, or filled teeth) - CORRECT ANSWER - Quantifies how the
PRIMARY dentition has been affected by dental caries
, DEFS (decayed, extracted, or filled surfaces) - CORRECT ANSWER - Quantifies how
each surface of the primary dentition has been affected by dental caries
Which population has the most number of UNRESTORED caries? - CORRECT
ANSWER - Blacks
Burs used for smoothing preps?
a) more flutes and shallow
b) more flutes and deeper
c) less flutes and shallow
d) less flutes and deeper - CORRECT ANSWER - a) More FLUTES and SHALLOW (red
burs)
Bur used that converges F and L walls?
a) 245
b) 7901
c) 169 - CORRECT ANSWER - a) 245
What bur do you use to SHAPE convergent walls for amalgam? - CORRECT ANSWER -
169
Which high speed bur gives a smoother surface? - CORRECT ANSWER - Plain cut
fissure bur
best cross cut fissure have a higher cutting efficiency
Bur used for polishing - CORRECT ANSWER - STEEL
