Deck 4: Microbiology of Periodontal Diseases

Question 1

Endotoxin is a:

A) Component of normal saliva
B) Pathogen that causes incipient root caries
C) Component of the cell wall of gram-positive rods
D) Pathogen that is easily degraded by salivary enzymes
E) Component of the cell wall of gram-negative organisms

Answer 1

Component of the cell wall of gram-negative organisms

Question 2

As plaque biofilm ages:

A) It is easily disturbed by self-cleansing mechanisms in saliva.
B) It grows in a uniform mass with new species attaching to the surface.
C) Filamentous forms invade the plaque biofilm and predominate over streptococcal forms.
D) Streptococcal forms invade the plaque biofilm and predominate over filamentous forms.

Answer 2

Filamentous forms invade the plaque biofilm and predominate over streptococcal forms.

Question 3

Mature supragingival plaque biofilm is characterized by:

A) Increased consumption of oxygen
B) The ability to invade the subgingival space
C) The presence of a single pathogenic species
D) Increased numbers of facultative anaerobes that inhibit obligate anaerobes

Answer 3

The ability to invade the subgingival space

Question 4

All of the following are features of the microflora of chronic periodontitis except one.Which feature is the exception?

A) Microflora varies among patients.
B) Biofilm is similar to that of gingivitis.
C) Biofilm can be altered with débridement.
D) Biofilm commonly contains Porphyromonas gingivalis.

Question 5

Based on the specific plaque hypothesis,gingival health can be monitored by:

A) Measuring the amount of plaque
B) Recording the number of times the teeth are brushed daily
C) Determining the total number of bacteria in plaque samples
D) Distinguishing the various types of bacteria in plaque samples

Question 6

Which factor facilitates the early growth of subgingival plaque?

A) Predominance of filamentous bacteria
B) Greater production of fermentation end-products
C) Presence of hemin-containing proteins in crevicular fluid
D) Formation of highly branched extracellular polysaccharides

Question 7

All of the following are factors in the virulence of gram-negative bacteria except one.Which factor is the exception?

A) Enzymes
B) Fimbriae
C) Leukotoxins
D) Cell membrane
E) Lipopolysaccharides

Question 8

Which characteristic describes the primary periodontal pathogens?

A) Motility
B) Lack of motility
C) Fimbriae on the cell surface
D) Filaments on the cell surface

Question 9

Localized aggressive periodontitis (LAP)is characterized by:

A) Lesions on specific teeth
B) Occurring in the older adult population
C) A microflora similar to that found in gingivitis
D) Aggressive destruction that occurs over many years

Question 10

Interactions among microbial species within plaque biofilm can do all of the following except one.Which one is the exception?

A) Produce nutrients for each other.
B) Coaggregate in saliva to promote clearance.
C) Aggregate to increase resistance to antimicrobial agents.
D) Prevent new bacterial species from penetrating the biofilm.

Question 11

Necrotizing ulcerative periodontitis:

A) Contains gram-positive rods.
B) Is asymptomatic for the patient.
C) Has a microflora similar to gingivitis.
D) Is often associated with spirochetal organisms.

Question 12

Which process facilitates bacterial aggregation?

A) Formation of levans
B) Decreased oxygen tension
C) Interaction of fimbriae with endotoxin
D) Nonselective attachment of gram-negative bacteria

Question 13

Early colonizing bacteria on tooth surfaces are:

A) Largely anaerobic
B) Associated with dental caries
C) Predominantly rodlike in shape
D) Predominantly cocci-like in shape

Question 14

Saliva plays an important role in pellicle formation on the tooth surfaces through its:

A) Production of antimicrobial proteins
B) Lubrication and cleansing of teeth surfaces
C) Ability to transport bacteria from one location to another
D) Production of proteins that adhere to clean tooth surfaces

Question 15

One function of receptor molecules on the surface of bacteria is to:

A) Repel bacteria from saliva.
B) Link bacteria to the pellicle.
C) Prevent linkage of bacteria to the pellicle.
D) Prevent the attraction of bacteria from saliva to pellicle.

Question 16

All of the following are characteristics of salivary glycoproteins except one.Which characteristic is the exception?

A) They form pellicle.
B) They promote bacterial aggregation.
C) They result from lysis of the bacterial cell wall.
D) They enhance binding of bacteria to tooth surfaces.

Question 17

The first step of bacterial growth into biofilm is the ability to:

A) Multiply rapidly.
B) Adhere to the pellicle.
C) Form bacterial coaggregations.
D) Survive in an acid environment.
E) Multiply in an aerobic environment.

Question 18

Saccharolytic (sugar-consuming)bacteria:

A) Usually possess fimbriae.
B) Produce amino acid end-products.
C) Cannot survive in an oxygenated environment.
D) Obtain energy from carbohydrate metabolism.

Question 19

What distinguishes supragingival dental plaque from material alba?

A) Number of bacteria
B) Location of the deposit on the tooth
C) Amount of calcium and phosphate ions present
D) Strength of adherence of the deposit to the tooth structure

Question 20

All of the following are characteristics of mature dental plaque biofilms except one.Which characteristic is the exception?

A) Highly uniform structure
B) Channels for nutrient exchange
C) Extracellular matrix glycocalyx
D) Multiple types of microorganisms

Question 21

Glycocalyx is a loose,gel-like polysaccharide substance surrounding gram-negative bacteria,causing both aggregation and adherence to tooth structure.

Question 22

Halitosis in 50% of individuals can be attributed to plaque biofilm in which oral microbial ecosystem?

A) Tongue
B) Oral mucosal surfaces
C) Saliva
D) Supragingival tooth surfaces
E) Subgingival tooth surfaces

Question 23

Bacteria can be classified by their ability to live and grow in the presence or absence of oxygen.Bacteria that cannot survive in oxygen-rich environments are known as:

A) Anaerobes
B) Aerobes
C) Facultative anaerobes
D) Obligate anaerobes

Question 24

In the nonspecific plaque hypothesis,plaque is homogeneous in nature,all microorganisms in plaque have pathogenic potential,and recognizing inflammation is related to age and the quantity of dental plaque biofilm.

Question 25

Which oral microbial ecosystem is distinctive as it represents a unique and changing environment for microorganisms that are protective in nature?

A) Tongue
B) Oral mucosal surfaces
C) Saliva
D) Supragingival tooth surfaces
E) Subgingival tooth surfaces

Question 26

Bacteria can be classified by their ability to live and grow in the presence or absence of oxygen.Bacteria requiring oxygen to grow are known as:

A) Anaerobes
B) Aerobes
C) Facultative anaerobes
D) Obligate anaerobes

Question 27

Plaque biofilm is not a random accumulation of assorted types of bacteria; rather,it is a specific and complex arrangement based on bacterial characteristics.

Question 28

Gram-staining procedures distinguish the characteristics of bacterial cell walls.

Question 29

Morphotype refers to bacterial shapes.

Question 30

Bacteria can be classified by their ability to live and grow in the presence or absence of oxygen.Bacteria that can grow in both oxygen-rich and oxygen-deficient environments are known as:

A) Anaerobes
B) Aerobes
C) Facultative anaerobes
D) Obligate anaerobes

Question 31

Bacteria can be classified by their ability to live and grow in the presence or absence of oxygen.Bacteria requiring no oxygen to grow are known as:

A) Anaerobes
B) Aerobes
C) Facultative anaerobes
D) Microbiota

Question 32

Streptococci are the predominant type of bacteria located in which oral microbial ecosystem?

A) Tongue
B) Oral mucosal surfaces
C) Saliva
D) Supragingival tooth surfaces
E) Subgingival tooth surfaces

Question 33

Dental plaque is the major etiologic factor in the initiation and progression of inflammatory periodontal disease.

Question 34

Dental plaque is not the major etiologic factor in the initiation and progression of inflammatory periodontal disease.

Question 35

Lipopolysaccharides are released during cell wall disruption,which is a characteristic of gram-positive bacteria.