Question 1

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.

Accepted Answer

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

Question 2

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

Accepted Answer

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

Question 3

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

Accepted Answer

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

Question 4

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

Accepted Answer

A)   Maxillary incisors
B)   Maxillary molars
C)   Mandibular incisors
D)   Mandibular molars

Question 5

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

Accepted Answer

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

Question 6

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

Accepted Answer

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

Question 7

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

Accepted Answer

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

Question 8

If a tooth with one root were to lose 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.

Accepted Answer

A)   The statement and the reason are correct.
B)   The statement and the reason are incorrect.
C)   The statement is correct,but the reason is incorrect.
D)   The statement is incorrect,but the reason is correct.

Question 9

Which of these teeth have two roots?

Accepted Answer

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

Question 10

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

Accepted Answer

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 or 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 11

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.

Accepted Answer

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

Question 12

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

Accepted Answer

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

Question 13

CASE STUDY
Monica is a 38-year-old woman who visits the office as a new client for an oral assessment and necessary care.Her health history indicates that she is in good health.Monica reports that she brushes three times per day and flosses every night,but her gums bleed every time she flosses.On completion of the full mouth radiographs,dentist's examination,and diagnosis,the dental hygienist completes the periodontal assessment and dental hygiene care plan.Findings include generalized,papillary and marginal gingival erythema;edema;and increased bleeding on probing at all proximal surfaces,especially teeth 8 and 9.No visible supragingival calculus is observed,but there is flat,easily explorable subgingival calculus present on all proximal surfaces,and there are rings of subgingival calculus in 4-mm pocket depths on the lingual surfaces of the mandibular molars,especially teeth 30 and 31.Furthermore,tooth 14 has facial and lingual recession of 4 mm,circumferential 3-mm pocket depths,a Class I mesial furcation,and cementum that is grainy and soft.
-Access to and instrumentation on the lingual aspect of teeth 30 and 31 is complicated by what anatomic feature?

Accepted Answer

A)   Mandibular posterior crowns are inclined more toward the lingual side than the roots,making access more difficult.
B)   Mandibular posterior crowns are inclined more toward the facial side 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 14

CASE STUDY
Monica is a 38-year-old woman who visits the office as a new client for an oral assessment and necessary care.Her health history indicates that she is in good health.Monica reports that she brushes three times per day and flosses every night,but her gums bleed every time she flosses.On completion of the full mouth radiographs,dentist's examination,and diagnosis,the dental hygienist completes the periodontal assessment and dental hygiene care plan.Findings include generalized,papillary and marginal gingival erythema;edema;and increased bleeding on probing at all proximal surfaces,especially teeth 8 and 9.No visible supragingival calculus is observed,but there is flat,easily explorable subgingival calculus present on all proximal surfaces,and there are rings of subgingival calculus in 4-mm pocket depths on the lingual surfaces of the mandibular molars,especially teeth 30 and 31.Furthermore,tooth 14 has facial and lingual recession of 4 mm,circumferential 3-mm pocket depths,a Class I mesial furcation,and cementum that is grainy and soft.
-The dental hygienist completes the instrumentation of the Class I furcation on the mesial aspect of tooth 14 from the lingual approach.What anatomic feature allows for this lingual access?

Accepted Answer

A)   The divergence of the mesial proximal surface toward the lingual aspect 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.

Question 15

CASE STUDY
Monica is a 38-year-old woman who visits the office as a new client for an oral assessment and necessary care.Her health history indicates that she is in good health.Monica reports that she brushes three times per day and flosses every night,but her gums bleed every time she flosses.On completion of the full mouth radiographs,dentist's examination,and diagnosis,the dental hygienist completes the periodontal assessment and dental hygiene care plan.Findings include generalized,papillary and marginal gingival erythema;edema;and increased bleeding on probing at all proximal surfaces,especially teeth 8 and 9.No visible supragingival calculus is observed,but there is flat,easily explorable subgingival calculus present on all proximal surfaces,and there are rings of subgingival calculus in 4-mm pocket depths on the lingual surfaces of the mandibular molars,especially teeth 30 and 31.Furthermore,tooth 14 has facial and lingual recession of 4 mm,circumferential 3-mm pocket depths,a Class I mesial furcation,and cementum that is grainy and soft.
-What is the most likely anatomic cause of the clinical findings at teeth 8 and 9?

Accepted Answer

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

Question 16

Which of the following statements about furcations is false?

Accepted Answer

A)   Furcation involvement occurs when there is loss of attachment apical to the cementoenamel junction (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 17

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

Accepted Answer

A)   The statement and the reason are correct.
B)   The statement and the reason are incorrect.
C)   The statement is correct,but the reason is incorrect.
D)   The statement is incorrect,but the reason is correct.

Question 18

The cementoenamel junction (CEJ)has the most proximal incisal or occlusal curvature on which of the following teeth?

Accepted Answer

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

Question 19

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

Accepted Answer

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 20

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

Accepted Answer

A)   Gemination
B)   Fusion
C)   Concrescence
D)   Dilaceration

Exam 26: Root Morphology and Instrumentation Implications