Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

iodc > rct irrigation > Flashcards

rct irrigation Flashcards

1
Q

What is responsible for endo infection?

A

Obligate anaerobic bacteria (polymicrobial)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the aims of irrigation?

A

Kill and remove microorganisms
Remove necrotic/inflamed tissue, dentine debris and smear layer
Provides lubrication and reduces friction for instrumentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the obstacles in disinfection?

A

1. Anatomical complexities- only 61% instrumented, rest remain infected
2. Smear layer- protection for bacteria, inhibits/delays irrigant into tubules
3. Fluid dynamics
4. Biofilm and resistant microbiota

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How are there anatomical complexities?

A

Webs
Loops
Cul de sac
Fins
Lateral canals
Apical delta

Types I-V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the smear layer consist of?

A

In/organic substances
Fragments of odontoblastic processes
Microorganisms
Necrotic debris

Created during cleaning and shaping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are fluid dynamics?

A

Irrigant only penetrates 1-2mm around needle
Absence of fluid motion- stagnation plane and no flushing of debris in apical region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are fluid dynamic rules for irrigation?

A

1. Side venting needle
2. Luer-lok syringe
3. Keep needle tip moving
4. Gentle pressure
5. If needle binds- stop
6. Constant agitation to improve flow
7. Size 27/30 gauge needle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How far should the needle be from the apex?

A

2mm

3-4mm if open apex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is dynamic pumping?

A

Introduce gutta percha point matched to master cone in a flooded canal to working length

Gentle in and out motion to stir up irrigant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a biofilm?

A

Any group of microorganisms in which cells stick to each other on a surface
Frequently embedded in EPS (extracellular polymeric substance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is EPS?

A

Polymeric conglomeration of extracellular DNA, proteins and polysaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are planktonic cells?

A

Single cells that may float in a liquid medium
- easily flushed out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is MIC?

A

Minimum inhibitory concentration
Can be 100-1000x higher in biofilm than suspension culture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is an example of a resistant bacteria?

A

E. faecalis
Can survive as monoculture in canals
Most freq species in root tx teeth w prevalence value of 90%
High resistance to NaOCl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are ideal characteristics of an endo irrigant?

A

1. Effective antimicrobial
2. Non-irritating
3. Stable in solution
4. Prolonged effect
5. Active in blood, serum and protein derivatives of tissue
6. Low surface tension
7. Not interfere w repair
8. Non staining
9. Doesn’t induce cell mediate I. response
10. Completely remove smear layer
11. Non toxic/antigenic/carcinogenic
12. No adverse effects on physical properties of exposed dentine
13. No adverse effects on sealing ability of materials
14. Easy to use
15. Inexpensive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are current irrigant solutions?

A

1. NaOCl
2. EDTA
3. CHX
4. IPI
5. MTAD
6. Hydrogen peroxide
7. PAD
8. Electronically activated water

17
Q

What is NaOCl?

A

Sodium hypochlorite- essentially supermarket bleach w/o thickener

1. Only irrigant that dissolves organic inc. biofilm
2. Effective against all endo bacteria
3. Affordable

0.5%- 30 min
2.5%- 10 min
4%- 5 min
5.25%- <30s

18
Q

What happens if you increase the temp of NaOCl?

A

1. Improve tissue dissolution (0.5% at 45C=5.25%)
2. 60C completely dissolve tissue but destroy osteoblasts and cause metal corrosion
3. Increase antimicrobial effect (2x each 5C rise)

19
Q

Why do you need to continuously replenish NaOCl?

A

Chloride ion responsible is rapidly consumed (2min) esp. in first phase

20
Q

What are disadvantages of NaOCl?

A

1. Minimal removal of dentine debris/smear layer
2. Reduces flexural strength
3. Rare allergy
4. Toxic to vital tissue (haemolysis, epithelial ulceration, necrosis)
5. Corrosion to metal

21
Q

What is EDTA?

A

Ethylenediamine tetra-acetic acid
Solution- 15-17% (penultimate rinse for 1-2mins)
Gel form- glyde- usually for sclerosed, aids lubrication
Synthetic AA
Removes smear layer as it’s a ‘chelating agent’
Not bactericidal/static (eventually kills by starvation due to chelation)
Relatively non toxic
Shouldn’t over use- excessive removal of dentine

22
Q

What is a chelating agent?

A

Scavenges up and forms ring shaped internal complexes w metallic ions, inc. Calcium

23
Q

Is citric acid used?

A

Not as effective chelating agent than EDTA

24
Q

What is chlorhexidine?

A

Cationic bisbiguanide antiseptic
Broad spectrum
Bacteriacidal at high conc
Static at low conc
Substantivity
Conc- 0.2-2%
Less toxic than NaOCl
No harmful effects to dentine

25
Q

What are disadvantages of CHX?

A

1. Forms precipitate w NaOCl- para chloroanaline (brown, potentially carcinogenic)- use intermediate as saline before using
2. No tissue dissolving effects
3. Can’t remove smear layer
4. Severe allergic reaction rare

26
Q

What is IPI?

A

Iodine (2%) potassium iodide (4%)
Acts as oxidising agent attacking key group proteins, nucleotides and FAs
Broad spectrum inc. E faecalis
Substantive
Low toxicity

27
Q

What are disadvantages of IPI?

A

1. Allergic reaction to iodine
2. Stains dentine
3. Not stable w organic
4. Doesn’t dissolve tissue/remove smear layer

28
Q

What is hydrogen peroxide?

A

Hydroxy free radicals destroy proteins and DNA
Conc- 3-5%
Active against bacteria, virus, yeast
Not used routinely anymore

29
Q

What are disadvantages of hydrogen peroxide?

A

1. Poor antimicrobial efficacy
2. Low tissue dissolving
3. Can release O2 gas (seepage in tissue may lead to air emphysema)

30
Q

What is MTAD?

A

Mixture of-
3% doxycycline (broad spectrum)
4.25% citric acid (removes smear layer)
Surface active detergent

No adverse effect on physical properties

31
Q

What are disadvantages of MTAD?

A

1. Less efficient on biofilm
2. Toxic
3. Expensive
4. Issues w bacterial resistance
5. Risk of tetracycline staining

32
Q

What is PAD?

A

Photo activated disinfection
Toluidine blue dye
Low power laser activated
Photosensitiser molecules attach to bacteria and singlet oxygen produced to rupture cell wall
Broad spectrum
No toxicity

33
Q

What are disadvantages of PAD?

A

1. Depends on power, length of exposure, absorption of light and distance
2. No benefit over others
3. Expensive

34
Q

What is electronically activated water?

A

Electrolyses saline solution
Creates hypochlorous acid and free radicals to remove biofilm and destroy bacteria
Lack studies showing efficacy/safety

35
Q

What is ultrasonic agitation of irrigants?

A

Acoustic micro steaming
Enhances antibacterial effect of irrigants
Disrupts biofilm
Eliminates more bacteria
Can use specific tips/standard files

iodc (63 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions