Microbio of RC System Flashcards
T/F: he root canal system provides an ideal environment for bacterial colonization
True
The ___ is warm, moist & nutritious (has lots of substrate) and has a variable but largely anaerobic climate.
RCS
This area is now largely protected from the host defenses due to lack of circulation in a diseased pulp.
RCS
If periapical lesions are present, is the tooth pulp inflamed or necrotic?
Necrotic
What are the the oxygen requirements of most RCS bacteria?
Obligate anaerobes
APical periodontitis is a _____ caused disease
Biofilm caused disease
What are the gram stains of MO in RCS?
Gram neg
What is the irrigant used to clean out the RCS?
Sodium Hypochlorite
Is there one single bacteria responsible for RCS infection?
No many are involved
Bacteria have to reach pulp chamber to cause _____
Irreversible pulpitits
_______ defend against bacteria
Periapical lesions
______ is the basic science most closely associated with the practice of Endo
Microbio
What type of necrosis is occuring when bacteria invade pulp?
Liquefactive necrosis
What are the 3 things the liquefactive necrosis depends upon as far as bacteria and patient?
Type of bacteria
Number of bacteria
Host defense mechanisms
What is the progression of RCS infections? 7 steps
- Carious Lesion or Trauma opens tubules to bacterial invasion
- Bacteria inflame pulp locally
- Inflammation may overcome pulpal defenses and localized abscesses may form in coronal pulp
- Infection increases in pulp and necrosis begins
- Necrosis involves entire RC System
- Infection uses “portals of exit” (apical foramen and lateral canals) to invade peri-radicular tissues (apical periodontitis)
- Periradicular infection occurs beyond apex ( apical abscess )
What are the 6 things biofilms must accomplish to cause disease?
- MO must adhere to host surfaces
- Obtain nutrients from the host
- Multiply
- Invade tissue
- Overcome host defenses
- Induce tissue damage
______ may be defined as a multicellular microbial community characterized by cells that are firmly attached to a surface and enmeshed in a self produced matrix of extra cellular polymeric substance(EPS), usually polysaccharide.
BIOFILM
What are the 2 techniques used to destroy microorgs in RCS?
Shape and irrigate
Can NaOCl travel into apical 1/3 of tooth?
Not without activation
Is isolation important in endo?
Yes; must use rubber dam to keep bacteria out of other tissues
What are the 6 functions of NaOCl in RCS?
- Disinfects over time
- Dilutes & Inactivates toxins
- Dissolves substrate over time
- Dissolves necrotic tissue over time
- Flushes & Floats out Debris
- Lubricates Canal
How often must NaOCl be replenished in RCS?
3-5 mins
How much NaOCl is used per visit?
10-12 cc
NaOCl must be in contact with shaped canal a minimum of ____ minutes after canal enlarged to #30 or larger.
30
_______: near universal acceptance as the intracanal medication of choice (esp. in necrotic cases)- pH between 11 and 12- Discourages most microbial growth- Long lasting (effective over extended periods)- No reported allergic responses- Easy to apply & remove as a paste- Available in clinic as “Calasept”
CaOH
Should antibiotics be used to relieve pain in RCS infection?
No
What are the 2 indications for antibiotics in RCS infections?
Acute P-R injections or immunologically suppressed
(Aerobes which can also survive in an anaerobic environment) May become more numerous & virulent with addition of oxygen
Facultative anaerobes
(must have anaerobic environment to survive), and cannot survive in an AEROBIC environment. Would it benefit our cause to add oxygen? NaOCl liberates O2
Obligate anaerobes
_______ is caused by bugs colonizing within the RCS
Intraradicular
_______ infection is usually a sequel to untreated intraradicular infection. Characterized by microbial invasion of the periradicular tissues resulting in inflammation & infection.
Extraradicular
______ infections: caused by bugs that initially invade and colonize necrotic pulp tissue within the RCS.
primary
______ infection caused by bugs not present in the primary infection but introduced into the RCS sometime following professional intervention (secondary to professional intervention; iatrogenic by definition)Example of infection is when symptoms arise in a previously ASYMPTOMATIC infected tooth if operator allowed R. Dam leakage or placed leaky temporary.
secondary
_______ infection caused by bugs that were members of a primary or secondary infection and in some way , resisted intracanal antimicrobial procedures and were able to endure periods of nutrient deprivation within the RCS. (i.e.) FAILURE OF RCT TO HEAL
persistent
If infection of RCS persist, what are still present?
Bacteria
The ability to form _____ has been regarded as a virulence factor. Neighboring cells of different species can produce enzymes such as: B-Lactamase, Catalase and proteinases that are retained in the biofilm matrix and can protect other bacteria against antibiotics and host defenses
Biofilm
_______, (formerly strep faecalis) A facultative anaerobe that is most frequently found WITHIN the RCS of recalcitrant or failing RCTs. Is not susceptible to CaOH (ph 11-12) because it thrives in high pH environment. NaOCl does not completely eradicate the microorganism.
E. faecalis
______ G+ anaerobe is sometimes isolated from P/A tissues OUTSIDE the RCS that do not seem to respond well to non surgical RCT. Surgery is necessary in a high % of these cases
Actinomyces israelii
________ (aka) S. Pyogenes (Gram +)can cause serious suppurative infections:–This bug is thought to produce penicillinase, a B lactamase that has the potential to render Penicillin ineffective*–Rx Augmentin = Amoxicillin + Clavulanic acid (inhibits penicillinase)
Staphylococcus Aureus
The _______ patient generally will also have systemic manifestations, such as fever, chills, lymphadenopathy, headache, and nausea. Because the reaction to the infection may occur very quickly, the involved tooth may or may not show radiographic evidence of a widened periodontal ligament space. However, in most cases the tooth elicits a positive response to percussion, and the periradicular area is tender to palpation. This is a serious (critical Infection) in fascial plane.
cellulitis
Muscle Attachments are important in relation to where the lesion“points.” If lesion exits coronal to muscle attachment, it is generally on attached gingiva or alveolar mucosa and we have a ________ ,which is MORE EASILY TREATED (No Systemic Involvement)
localized abscess
______ are potential anatomic areas that exist between the fascia and underlying organs and other tissues. During an infection, these spaces are formed as a result of the spread of purulent exudate.
Fascial spaces
T/F: The spread of infections of odontogenic origin into the fascial spaces of the head and neck is determined by the location of the root end of the involved tooth in relation to its overlying buccal or lingual cortical plate and the relationship of the apex to the attachment of a muscle.
True
