Lec 2

Question 1

Root canal is ideal environment for microorganisms how?

Answer 1

Warm, moist, nutrients, anaerobic

Question 2

what is apical periodontitis

Answer 2

inflammatory response to bacteria in RCS

Question 3

what is a granuloma

Answer 3

sign of chronic inflammation
moves bone away from bacteria to protect it

Question 4

coagulation necrosis involves?

Answer 4

trauma
no bacteria

Question 5

liquefaction necrosis involves?

Answer 5

bacteria

Question 6

most pathologic bacteria found in RCS are?

Answer 6

gram neg anaerobes:
-porphyromonas
-prevotella
-peptostreptococcus
-fusobacterium
-eubacterium
-actinomyces

all release LPS (endotoxin)

Question 7

canal walls are conductive to formation of a

Answer 7

biofilm
apical periodontitis is a disease caused by biofilmn

Question 8

T or F:
a single microorganism causes RC disease

Answer 8

FALSE

Question 9

what is the progression of RC infection (7)

Answer 9

1. carious lesion or trauma exposes tooth to bacteria
2. bacteria inflame pulp locally
3. localized abscess forms in pulp
4. infection grows and necrosis begins
5. necrosis involves entire RCS
6. infection leaves root thru apex or lateral canals
7. infection and apical abscess occurs beyond apex
   *abscess only caused by necrotic pulp!

Question 10

what is ludwigs angina

Answer 10

infection in SL and SM glands/space
can be fatal, closes airway

Question 11

biofilm must accomplish what 6 things to cause disease in RCS

Answer 11

1. MO adhere to host surfaces
2. obtain nutrients from host
3. multiply
4. invade tissue
5. overcome host defenses
6. induce tissue damage

Question 12

what are the most common bacteria found in biofilm of endodontic infections

Answer 12

anaerobic gram -
prevotella
porphyromonas

Question 13

what are facultative anaerobes

Answer 13

can survive with or without oxygen

Question 14

what are obligate anaerobes

Answer 14

must be in anaerobic environment, no oxygen

Question 15

what kills anaerobic pathogens in RCS?

Answer 15

8.3% NaOCl (sodium hypochlorite)
-releases O2 which kills anaerobic bacteria
also filing the canals to clean out

Question 16

6 functions of NaOCl are:

Answer 16

1.disinfects canal
2. dilutes and inactivates toxins
3. dissolves substrates
4. dissolves necrotic tissue
5. flushes out bacteria and debris
6. lubricates canal

Question 17

NaOCl must be replenished how often and why?

Answer 17

degrades rapidly to NaCl
replenish every 3-5 min
need about 10-12 ccs for 1 case
Must sit for 30 min

Question 18

Intracanal medications are

Answer 18

placed within canal to kill MO
CaOH is the intracanal med of choice

Question 19

CaOH benefits

Answer 19

pH 11-12
stops most MO growth
long lasting effects
no reported allergic responses
easy to apply and remove as paste
“Ultracal” in clinic

Question 20

what is obturation

Answer 20

sealing the RCS after tx w/ gutta percha

Question 21

you should use antibiotics for pain T or F

Answer 21

FALSE
ABX for pain is useless
-only use ABX for acute inflammation, swelling (fever) and immunologically suppressed PTs

Question 22

how are endodontic infections classified? (4)

Answer 22

according to:
-location
-symptoms (acute or chronic)
-degree of virulence
-organization (localized or diffuse/spreading)

Question 23

Endodontic infection classifications: LOCATION

Answer 23

intraradicular: caused by MO colonizing within the RCS

extraradicular: microbial invasion of periradicular tissues, leads to inflammation and infection, AAA or CAA

Question 24

3 subclasses of intraradicular infections

Answer 24

1. primary infection: caused by MO that invade and colonize necrotic pulp in RCS
2. secondary infection: MO not found in primary but introduced to RCS following iatrogenic tx (symptoms arise in previously asymptomatic tooth due to leakage by operator, etc.)
3. persistent infection: MO from primary or secondary infection resist and return, failure of RCT to heal

Question 25

what are bacterial virulence factors?

Answer 25

ability to form biofilm: protect bacteria from ABX and host defenses

enzymes (collagenase, chondroitinase, hylauronidase)

endotoxins and exotoxins

LPS in gram -

peptides/AAs

Question 26

what is important about S. aureas / S. pyogenes

Answer 26

gram +
can cause serious infections
release penicillinase (B lactamase) that blocks penicillin
tx w/ augmentin

Question 27

localized swelling and cellulitis caused by

Answer 27

bacteria from infected pulp enter periradicular tissue and immune system cannot suppress them.
Pt will show signs of acute periradicular abscess or cellulitis or both, causes swelling, fever, pain.
Cellulitis occurs when swelling extends into fascial planes (critical infection)

Question 28

how do critical infections develop?

Answer 28

spread of infection into fascial spaces (cellulitis)
can be lethal if not treated properly
location of infection in tooth determines where the spread of infection will go

Question 29

why are mandibular molar infections dangerous?

Answer 29

2nd and 3rd molar infections can be dangerous
Cellulitis can occur in SM space, make swallowing difficult
Can then spread to SL and Submental spaces
Causes life threatening infection called Ludwig’s Angina

Question 30

what is ludwig’s angina

Answer 30

cellulitis in SM space
infection points apical to attachment of mylohyoid and superior to platysma
I&D needed to control infection

Question 31

what is a biofilm

Answer 31

multicellular microbial community firmly attached to a surface and in a self produced matrix of extracellular substances, usually polysaccaharides

Question 32

for patients with symptomatic pulpitis, symptomatic apical periodontitis, DST or localized swelling, you should give them antibiotics

Answer 32

NO
only creating resistance

Question 33

spread of infections - critical infections
tooth location

Answer 33

if apices of tooth located below the muscle attachment, the infection can spread
-localized infection if is coronal to muscle attachment