Deck 5: Oral Microbiology and Plaque-Associated Diseases

Question 1

What is the most caries-conductive component of our diet?

A)Protein
B)Sucrose
C)Fatty acid
D)Cellulose

Answer 1

Sucrose

Question 2

For microorganisms to colonize the mouth (become established members of the oral microbiota), they must:

A)not be infected with bacteriophages.
B)be gram-positive bacteria that are aciduric.
C)attach to oral surfaces and be able to multiply in the oral environment.
D)come from the nonhuman environment (e.g., water, dust, soil).

Answer 2

attach to oral surfaces and be able to multiply in the oral environment.

Question 3

What causes the critical pH to be reached during formation of dental caries?

A)The saliva stagnates and putrefies, producing a large amount of acid.
B)The bacteria in saliva cause an immune response to occur, lowering the pH in the mouth.
C)Lysozyme in saliva lyses bacteria, causing the release of internal chemicals from the dead bacterial cells, which lower the pH in the mouth.
D)Plaque bacteria convert dietary sugar into acids.

Answer 3

Plaque bacteria convert dietary sugar into acids.

Question 4

The pellicle is best defined as:

A)part of the outer membrane of gram-negative bacterial cells.
B)a proteinaceous layer that coats the teeth exposed to saliva.
C)that part of the bacterial gene that codes for acid production.
D)the protein coat of viruses.

Question 5

Untreated dental caries can lead to:

A)strep throat.
B)necrotizing ulcerative gingivitis.
C)pulpitis.
D)fever blisters.

Question 6

How many different genera of bacteria may be isolated from human mouths?

A)At least 42
B)100
C)100 million
D)200 billion

Question 7

Calculus is:

A)accumulated food debris that occurs in the absence of oral hygiene.
B)mineralized plaque.
C)a microbial mass that accumulates in the absence of oral hygiene.
D)an aggregation of white blood cells that come from the gingival sulcus.

Question 8

What actually destroys the tooth enamel in dental caries?

A)Amino acids in the diet
B)Acids made by bacteria
C)Fats in saliva
D)Nucleic acids

Question 9

Oral biofilm (dental plaque) is:

A)accumulated food debris that occurs in the absence of oral hygiene.
B)an accumulation of glycoproteins from saliva.
C)a microbial mass that accumulates in the absence of oral hygiene.
D)an aggregation of white blood cells that come from the gingival sulcus.

Question 10

Mutans streptococci convert _____ to glucans that are used by these bacteria to form plaque.

A)starch
B)omega-3 fatty acids
C)sucrose
D)fructose

Question 11

Further progression of a periapical infection may cause:

A)strep throat.
B)cellulitis.
C)pulpitis.
D)enamel caries.

Question 12

Most of the bacteria important in causing periodontal diseases are:

A)in the group called Mutans streptococci.
B)gram-positive.
C)gram-negative.
D)also important causes of strep throat.

Question 13

Which of the following bacteria is the most important in causing the progression of a carious lesion after the lesion has been initiated?

A)Streptococcus sanguis
B)Lactobacillus acidophilus
C)Porphyromonas gingivalis
D)Prevotella intermedia

Question 14

The two most important bacteria in causing dental caries are:

A)Mutans streptococci and Staphylococcus aureus.
B)Lactobacillus acidophilus and Porphyromonas gingivalis.
C)Mutans streptococci and Lactobacillus acidophilus.
D)Aggregatibacter actinomycetemcomitans and mutans streptococci.

Question 15

Which of the following periodontal diseases occurs in persons with normal body defense mechanisms?

A)Chronic
B)Rapidly progressive
C)Prepubertal
D)Juvenile

Question 16

How soon do bacteria begin to reattach to the tooth surface and start forming plaque again after a prophy?

A)Within seconds
B)12 hours
C)One day
D)One week

Question 17

Dental plaque is best defined as:

A)a microbial mass.
B)composed of pieces of food that have stuck to the teeth.
C)mineralized proteins.
D)dried saliva.

Question 18

The three mechanisms of action of topical fluoride are (1) inhibiting bacterial metabolism after diffusing into the bacteria as hydrogen fluoride, (2) inhibiting demineralization when present at the crystal surfaces of teeth during an acid challenge, and (3):

A)enhancing remineralization.
B)stopping plaque formation.
C)killing all oral bacteria.
D)enhancing saliva flow.

Question 19

Removing dental plaque and instituting good oral hygiene will reverse which of the following diseases?

A)Gingivitis
B)Periodontitis
C)Dental caries in dentin
D)Strep throat

Question 20

Where do periapical infections occur?

A)Around the tooth pulp
B)In the outer portion of the tooth enamel
C)In the deep part of the tooth dentin
D)In the tissue around the tooth apex

Question 21

After a prophylaxis, plaque begins to re-form within __________.

Question 22

The same bacteria that cause dental caries also cause periodontal diseases.

Question 23

The slightest trauma to the mouth that results in bleeding can lead to:

A)dental caries.
B)transient bacteremia.
C)chronic periodontitis.
D)necrotizing ulcerative gingivitis.

Question 24

Simple or acute gingivitis involves the bone in which the teeth are set.

Question 25

The names of different types of caries are based upon___________.

Question 26

Plaque causes periodontal diseases.

Question 27

Members of the normal oral flora can cause:

A)tetanus.
B)measles.
C)actinomycosis.
D)mumps.

Question 28

The best approach to preventing periodontal disease is to ________ and _________.

Question 29

Periodontitis occurs only in older adults.