NBDE part 2- Endodontics Exam
2025 Questions and Answers 100%
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maxillary central incisor average length is ______. Shape of access opening should be
___________ - ✔✔22-23mm
Oval-triangular
Maxillary central, lateral, and canine roots have ________ axial inclination - ✔✔distal
Shape of access opening for maxillary lateral incisor - ✔✔oval
Maxillary canine average length is ___________ and the shape of access opening should
be _________ - ✔✔26-27mm
oval
Mandibular central incisor- most common # of canals and foramen - ✔✔1 canal, 1
foramen (70%)
2 canals, 1 foramen (24%)
2 canals, 2 foramina (6%)
When theres 2 canals, the labial canal is the straighter one
Mandibular lateral incisor- most common # of canals/foramen - ✔✔1 canal, 1 foramen
(56%)
2 canals, 2 foramina (30%)
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,2 canals, 1 foramen (14%)
___% of mandibular laterals have 2 canals - ✔✔44%
Mandibular canines- most common # of canals/foramen - ✔✔1 canal (94%)
2 canals 2 foramina (6%)
Maxillary first premolar- most common # of canals/foramen - ✔✔2 roots and 2 canals
(72%)
2 roots (78%)- 2 roots usually equal in length from apex to cusp, lingual root and canal
may be wider
1 root (22%)
2 canals, 2 foramina (72%)
2 canals, 1 foramen (13%)
1 canal and 1 foramen (9%)
3 canals, 3 foramina (6%)
With maxillary first premolar, ______ perforation is common due to __________ -
✔✔Mesial
Mesial concavity
Maxillary second molar- most common # of canals/foramen - ✔✔1 canal and 1 foramen
(75%)
2 canals, 2 foramina (24%)
3 canals (1%)
maxillary first premolars/second premolars have higher incidence of accessory canals -
✔✔maxillary second premolars
(60%)
Mandibular first premolar- most common # of canals/foramen - ✔✔1 canal, 1 foramen
(73%)
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, 2 canals, 2 foramina (20%)
2 canals, 1 foramen (7%)
_____% of mandibular first premolars have 2 canals - ✔✔27%
Mandibular second premolar- most common # of canals/foramen - ✔✔1 canal, 1
foramen (86%)
2 canals, 2 foramina (12%)
2 canals, 1 foramen (2%)
Maxillary first molar-most common # of canals/foramen - ✔✔4 canals, 3 foramina
(56%)
3 canals, 3 foramina (42%)
5 canals, 3 foramina (2%)
______________________ has the highest endodontic failure rate - ✔✔maxillary 1st
molar
The DB orifice is found _________________ to the MB orifice - ✔✔2-3mm distal and
slightly palatal aspect
Maxillary second molar-most common # of canals/foramen - ✔✔3 roots (54%), 3
foramen
Mandibular first molar- most common # of canals/foramen - ✔✔Trapezoidal outline
2 roots 3 canals
2 roots (98%), 3 roots (2%)
2 canals (6%), 3 canals (65%), 4 canals (29%)
If the 4th canal is present, it is in the distal root
For a mandibular first molar, the ______ wall is most easily perforated due to
__________________ - ✔✔Lingual
Lingual inclination
Mandibular second molar- most common # of canals/foramen - ✔✔Trapezoidal
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2025 Questions and Answers 100%
Pass
maxillary central incisor average length is ______. Shape of access opening should be
___________ - ✔✔22-23mm
Oval-triangular
Maxillary central, lateral, and canine roots have ________ axial inclination - ✔✔distal
Shape of access opening for maxillary lateral incisor - ✔✔oval
Maxillary canine average length is ___________ and the shape of access opening should
be _________ - ✔✔26-27mm
oval
Mandibular central incisor- most common # of canals and foramen - ✔✔1 canal, 1
foramen (70%)
2 canals, 1 foramen (24%)
2 canals, 2 foramina (6%)
When theres 2 canals, the labial canal is the straighter one
Mandibular lateral incisor- most common # of canals/foramen - ✔✔1 canal, 1 foramen
(56%)
2 canals, 2 foramina (30%)
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,2 canals, 1 foramen (14%)
___% of mandibular laterals have 2 canals - ✔✔44%
Mandibular canines- most common # of canals/foramen - ✔✔1 canal (94%)
2 canals 2 foramina (6%)
Maxillary first premolar- most common # of canals/foramen - ✔✔2 roots and 2 canals
(72%)
2 roots (78%)- 2 roots usually equal in length from apex to cusp, lingual root and canal
may be wider
1 root (22%)
2 canals, 2 foramina (72%)
2 canals, 1 foramen (13%)
1 canal and 1 foramen (9%)
3 canals, 3 foramina (6%)
With maxillary first premolar, ______ perforation is common due to __________ -
✔✔Mesial
Mesial concavity
Maxillary second molar- most common # of canals/foramen - ✔✔1 canal and 1 foramen
(75%)
2 canals, 2 foramina (24%)
3 canals (1%)
maxillary first premolars/second premolars have higher incidence of accessory canals -
✔✔maxillary second premolars
(60%)
Mandibular first premolar- most common # of canals/foramen - ✔✔1 canal, 1 foramen
(73%)
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, 2 canals, 2 foramina (20%)
2 canals, 1 foramen (7%)
_____% of mandibular first premolars have 2 canals - ✔✔27%
Mandibular second premolar- most common # of canals/foramen - ✔✔1 canal, 1
foramen (86%)
2 canals, 2 foramina (12%)
2 canals, 1 foramen (2%)
Maxillary first molar-most common # of canals/foramen - ✔✔4 canals, 3 foramina
(56%)
3 canals, 3 foramina (42%)
5 canals, 3 foramina (2%)
______________________ has the highest endodontic failure rate - ✔✔maxillary 1st
molar
The DB orifice is found _________________ to the MB orifice - ✔✔2-3mm distal and
slightly palatal aspect
Maxillary second molar-most common # of canals/foramen - ✔✔3 roots (54%), 3
foramen
Mandibular first molar- most common # of canals/foramen - ✔✔Trapezoidal outline
2 roots 3 canals
2 roots (98%), 3 roots (2%)
2 canals (6%), 3 canals (65%), 4 canals (29%)
If the 4th canal is present, it is in the distal root
For a mandibular first molar, the ______ wall is most easily perforated due to
__________________ - ✔✔Lingual
Lingual inclination
Mandibular second molar- most common # of canals/foramen - ✔✔Trapezoidal
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