Deck 28: Root Morphology and Instrumentation Implications

Question 1

Which of these teeth have two roots?

A) Maxillary and mandibular first molars
B) Maxillary premolars and maxillary molars
C) Maxillary premolars and mandibular molars
D) Mandibular first and mandibular second molars

Answer 1

Mandibular first and mandibular second molars

Question 2

The root trunk on which aspect of a maxillary first molar is the longest?

A) Mesial
B) Facial
C) Distal
D) Lingual

Answer 2

Distal

Question 3

Teeth with roots that are broad proximally and have narrow facial and lingual surfaces are:

A) maxillary incisors.
B) maxillary canines.
C) mandibular incisors.
D) mandibular canines.

Answer 3

mandibular incisors.

Question 4

What term is used specifically for the bone between the roots of a molar?

A) Furcal
B) Interradicular
C) Interseptal
D) Alveolar

Question 5

Which of the following statements about furcations is false?

A) Furcation involvement occurs when there is loss of attachment apical to the CEJ.
B) Furcations located closest to the CEJ are most likely to become involved with periodontal disease.
C) Furcations are generally most cervical on the facial surface of mandibular first permanent molars.
D) The more cervical the furcation, the more stable the tooth.

Question 6

Cervical enamel projections (CEPs) are "droplets" of enamel that form on the surface of the roots of multirooted teeth, generally near the area of a furcation. CEPs are most frequently observed on mandibular molars.

A) Both statements are true.
B) Both statements are false.
C) The first statement is true, and the second statement is false.
D) The first statement is false, and the second statement is true.

Question 7

How many distal root surfaces are there from a facial approach on a maxillary first molar?

A) None
B) One
C) Two
D) Three

Question 8

All teeth are positioned in the dental arches so that their crowns are oriented or slanted more toward the mesial and their roots have a more distal orientation except:

A) maxillary incisors.
B) maxillary molars.
C) mandibular incisors.
D) mandibular molars.

Question 9

The CEJ has the most proximal incisal/occlusal curvature on which of the following teeth?

A) Incisors
B) Canines
C) Premolars
D) Molars

Question 10

Which of the following statements about the clinical crown of a tooth is true?

A) It is that part of a tooth covered with enamel.
B) It is only that part of the tooth that can be seen in the oral cavity.
C) Its apical limit is determined by the gingival margin.
D) It may include the anatomic crown and part of the anatomic root.

Question 11

Which of the following single rooted teeth has the most convergence or taper of the proximal root surfaces toward the lingual?

A) Maxillary central incisor
B) Mandibular central incisor
C) Mandibular canine
D) Mandibular first premolar

Question 12

The name of the condition when teeth within an arch are so crowded that two adjacent teeth contact each other on the root and are connected by cementum is:

A) gemination.
B) fusion.
C) concrescence.
D) dilaceration.

Question 13

When permanent teeth have more than one root, there is a portion of the root called the root trunk. The root trunk is between the furcation and the apical foramen.

A) Both statements are true.
B) Both statements are false.
C) The first statement is true, and the second statement is false.
D) The first statement is false, and the second statement is true.

Question 14

The proximal surfaces of roots that are narrower on the lingual than the facial surface are more readily approached from the lingual because there is more proximal space there for the adaptation of instruments.

A) Both the statement and the reason are correct, and they are related.
B) Both the statement and the reason are correct, but they are not related.
C) The statement is correct, but the reason is not.
D) The statement is not correct, but the reason is correct.
E) Neither the statement nor the reason is correct.

Question 15

Which of these teeth do not have a furcation on the mesial?

A) Maxillary first premolars
B) Maxillary second premolars
C) Maxillary first molars
D) Maxillary second molars

Question 16

Which of the following teeth is most likely to have a furcal concavity?

A) Maxillary first molar
B) Mandibular first molar
C) Maxillary second molar
D) Mandibular second molar

Question 17

Dentinal hypersensitivity may occur as a result of the removal of cementum during root instrumentation. The goal of root instrumentation is to remove all cementum.

A) Both statements are true.
B) Both statements are false.
C) The first statement is true, and the second statement is false.
D) The first statement is false, and the second statement is true.

Question 18

Which of the following teeth is most likely to have a facial and lingual root?

A) Maxillary lateral incisor
B) Mandibular canine
C) Maxillary first premolar
D) Mandibular first molar

Question 19

If a tooth with one root lost one-third of its attachment length, its loss of attachment surface would be greater than one-third because the root is larger in the cervical one-third of the tooth.

A) Both the statement and the reason are correct, and they are related.
B) Both the statement and the reason are correct, but they are not related.
C) The statement is correct, but the reason is not.
D) The statement is not correct, but the reason is correct.
E) Neither the statement nor the reason is correct.

Question 20

Which of the following general statements about the root of a single rooted tooth is correct?

A) From a facial or lingual view, an imaginary midline of the root has a slight distal inclination to an imaginary midline of the crown.
B) From a facial or lingual view, proximal surfaces diverge apically.
C) From an incisal/occlusal view, proximal surfaces diverge toward the lingual.
D) From an incisal view of a horizontal cervical cross-section, the shape is round in contour.

Question 21

To complete instrumentation on No. 14, the dental hygienist will:

A) completely remove the calculus.
B) remove as much calculus as possible and remove some cementum during root planing.
C) remove as much calculus as possible and completely remove the cementum during root planing.
D) remove the calculus during scaling and remove cementum during root planing knowing that dentin may be exposed resulting in possible dentinal hypersensitivity.

Question 22

The area of No. 11 and No. 12 will provide instrumentation challenges due to which of the following canine and first premolar features?

A) Inclined axial positioning of the maxillary canine and narrow premolar proximal surfaces
B) Ovoid maxillary canine root shape and cone-shaped premolar root
C) Prominent maxillary canine root concavities and prominent distal premolar root concavity
D) Long canine crown with a broad distal crest of curvature and short first premolar crown with a prominent mesial concavity

Question 23

Access to and instrumentation on the lingual aspect of No. 30 and No. 31 is complicated by what anatomic feature?

A) Mandibular posterior crowns are inclined more toward the lingual than the roots, making access more difficult.
B) Mandibular posterior crowns are inclined more toward the facial than the roots making access more difficult.
C) The mandibular first molar mesial furcal concavity makes access more difficult.
D) The mandibular second molar mesial concavity makes access more difficult.

Question 24

What is the most likely anatomic cause of the clinical findings at No. 8 and No. 9?

A) Prominent flat CEJ shape of the mesial of the maxillary central incisors allow excess calculus to remain undetected.
B) Flat distal CEJ concavities on the distal of the maxillary central incisors make complete calculus removal difficult.
C) Prominent V-shaped CEJ concavities on the mesial of the maxillary central incisors make calculus identification and complete removal difficult.
D) Flat V-shaped CEJ concavities on the distal of the maxillary central incisors make calculus identification and complete removal a challenge.

Question 25

The dental hygienist completes the instrumentation of the Class I furcation on the mesial of No. 14 from the lingual approach. What anatomic feature allows for this lingual access?

A) The divergence of the mesial proximal surface toward the lingual allows for this access.
B) The short mesial root trunk and the lingual location of the furcation allow for this access.
C) The proximal and furcal concavities on the mesial root allow for this access.
D) The long root trunk, close root proximity and distal orientation of the roots allow for this access.