9 - Endodontic Microbiology

Question 1

role of bacteria in endo

Answer 1

1. Bacteria required for pulp disease
2. Pulp damage required for infection
3. Bacteria usually confined in canal

Question 2

what is the main source of bacterial contamination of pulp tissue

Answer 2

caries

Question 3

how many dentinal tubules per sq. mm of dentin

Answer 3

15,000

Question 4

diameter of dentinal tubule

Answer 4

1 to 4 microns

Question 5

most bacteria is ___micron

Answer 5

less than 1 micron

Question 6

who was the first person/year to first associate bacteria with pulpal disease

Answer 6

W.D. Miller 1890

Question 7

who proved and year than bacteria are the cause of pulpal and PA disease

Answer 7

Kakehashi 1965

Question 8

T/F: pulp status is very important in its susceptibility to colonization

Answer 8

TRUE

Question 9

because of lack of circulation, what is absent in necrotic pulp

Answer 9

normal host defense

Question 10

what causes an apical lesion

Answer 10

toxins and bacteria

Question 11

what is done to eliminate infection from canal

Answer 11

endo therapy

Question 12

is the body defense capable of taking care of apical lesion

Answer 12

yes

Question 13

routes of bacterial contamination

Answer 13

1. Open Cavity
2. Dentinal Tubules
3. Periodontal disease
4. Developmental defects
5. Infection from another tooth?

Question 14

what are examples of developmental defects

Answer 14

Question 15

is there one specific bacteria in endo infections

Answer 15

no

Question 16

are endo infections native to oral cavity

Answer 16

yes

Question 17

endo infections are [single OR mixed] infections

Answer 17

MIXED

Question 18

what bacteria are in caries (ea. layer)

Answer 18

1. S. Mutans on superficial layers
2. Anaerobes in deepest layers
3. Actinomyces in root caries

Question 19

T/F: Following pulp exposure numerous species of opportunistic bacteria can invade and colonize the pulp

Answer 19

TRUE

Question 20

what are bacteria in polymicrobial infections

Answer 20

1. Strict anaerobic bacteria
2. Facultative anaerobes
3. Rarely aerobes

Question 21

The predominance of ___ suggests that a selective process favoring the growth of these bacteria takes place. In time, the proportion as well as the total number of ___ increases

Answer 21

strict anaerobes; strict anaerobes

Question 22

what is the ecological environement of root canal

Answer 22

1. Rich substrate of nutrients (polypetides and aminoacids)
2. Low oxygen tension
3. Bacterial interactions

Question 23

T/F: the growth of some bacterial species INDEPENDENT on the metabolic byproducts of other species

Answer 23

FALSE! DEPENDENT!

Question 24

what is bacteria organized in complex microbial community

Answer 24

biofilm

Question 25

what is composed of great variety of bacteria with different ecological requirements and pathogenic potential

Answer 25

biofilm

Question 26

what protects microorganisms from host immunological resistance

Answer 26

biofilm

Question 27

what protects microorganisms from therapeutic measures such as medicaments and irrigating solutions

Answer 27

biofilm

Question 28

can the same patient have different combination of bacteria on one tooth compared to another tooth in the same oral cavity

Answer 28

YES

Question 29

is black pigmented bacteria (BPB) anaerobic or aerobic

Answer 29

anaerobic

Question 30

BPB previously know as what

Answer 30

black pigmented bacteria (BPB) previously known as bacteriodes

Question 31

anaerobic organisms are currently classified in what genus

Answer 31

prevotella and porphyromonas

Question 32

what is the accurate way of detecting and classifying microorganisms to find DNA or RNA

Answer 32

PCR

Question 33

what can invade periapical lesion and cause a rare persistent infection that will not heal after endodontic therapy

Answer 33

actinomyces isralii

Question 34

Associated with failing root canals Can persists after root canal treatment Resistant to some medications Difficult to erradicate

Answer 34

enterococcous faecalis

Question 35

Associated with painful symptoms during root canal infections Involved with other microorganisms in mixed infections

Answer 35

prevotella melaninogenica

Question 36

___ is the most common BPB cultivated from endodontic infections

Answer 36

Porphyromonas Nigrescens

Question 37

what is responsible for dentin staining during endo infections

Answer 37

Porphyromonas Nigrescens or just an endo bacteria

Question 38

Periapical healing occurred in 94% of cases with [positive or negative] cultures at time of obturation

Answer 38

negative

Question 39

Only 68% healing in cases that had [positive or negative] cultures at time of obturation

Answer 39

positive

Question 40

what are other organisms found in the pulp

Answer 40

1. Viruses (HIV) 2. Yeasts (Candida Albicans) 3. Spirochetes

Question 41

7% of 692 samples of therapy resistant chronic apical periodontitis showed the presence of what

Answer 41

fungi/candida albicans

Question 42

tests to detect bacteria

Answer 42

1. sensitivity test 2. gram stain 3. special cultures needed for anaerobic bacteria 4. PCR testing

Question 43

what test to determine which antibiotics would be most affective against bacteria

Answer 43

sensitivity

Question 44

what test to determine bacteria type

Answer 44

gram stain

Question 45

when to culture

Answer 45

1. Tooth does not respond to treatment 2. Persistent symptoms 3. Sinus tract will not heal 4. Persistent exudate in canal

Question 46

what is the aseptic technique

Answer 46

1. Field of operation 2. Sterilized instruments and materials 3. Disinfected surfaces in operatory 4. Operator barrier protection (gloves, mask, PROTECTIVE GLASSES etc.) 5. Canal disinfection 6. Coronal seal

Question 47

endo infection will persist until when

Answer 47

until source is removed

Question 48

what is done in endodontic therapy against bacteria

Answer 48

1. Chemo-mechanical debridement 2. Use of antimicrobials 3. Canal obturation 4. Coronal restoration

Question 49

are antibiotics effective in endo? why?

Answer 49

Because of a lack of blood supply antibiotics are not effective in destroying the reservoir of bacteria located in the root canal

Question 50

can antibiotics be used as a substitute for tx in endo

Answer 50

no

Question 51

can a majority of endo infections be treated without the use of antibiotics

Answer 51

yes

Question 52

can you use prophylactic antibiotics to prevent flare-ups in endo

Answer 52

no - not justified

Question 53

what bacteria can be found in root caries

Answer 53

actinomyces

Question 54

what bacteria can be found in caries

Answer 54

strep mutans

Question 55

what bacteria found in periodontitis

Answer 55

porphyromonas

Question 56

can viruses be found in the pulp space?

Answer 56

YES! HIV and Hep B

Question 57

what bacteria is found in failing root canals and is resistant to most root canal medications

Answer 57

enterococcus faecalis

Question 58

T/F: there is a specific bacteria that causes endodontic infections

Answer 58

FALSE! many different bacteria!

Question 59

T/F: endodontic infections are mostly polymicrobial

Answer 59

TRUE (polymicrobial = multiple bacterias)

Question 60

T/F: bacteria can gain access into the pulp thru dentinal tubules

Answer 60

TRUE

Question 61

T/F: Infections in the root canal can be self sustaining due to metabolic products that are excreted by one type of bacteria and utilized as nutrients by other species of bacteria

Answer 61

TRUE

Question 62

T/F: a carious exposure is needed for bacteria to access the pulp

Answer 62

FALSE! must enter via tubules

Question 63

T/F: The principal etiology for pulpal disease is microbial

Answer 63

TRUE! (specifically polymicrobial)

Question 64

T/F: bacteria in endodontic infections are mostly aerobic

Answer 64

FALSE! anaerobic!