Root Canal Irrigation

Question 1

Microbiology of primary root canal infection?

Answer 1

Polymicrobial

Obliagte anaerobic bacteria

Question 2

Use of irrigants?

Answer 2

Kill and remove microorganis
Remove microorganism
Remove dentine debris and smear layer
Lubrication for insturcments

Question 3

Why need irrigations?

Answer 3

Only 60% canal wall instrumented

Irregular and complex system - lateral

Question 4

What is smear layer?

Answer 4

Created during cleaning and shaping

Inorganic and organic substance, microorganism and nectrotic debris

Question 5

Issue w/ smear layer?

Answer 5

Protect bacteria

Inhibit penetration irrigant into tubules

Question 6

What needle use for irrigations?

Answer 6

Side venting needle

Question 7

What is biofilm?

Answer 7

Adherent cells/ microorganism in matrix of extracellular polymeric substance

Question 8

What is a resistant microbe found in root canals?

Answer 8

E. Faecalis - resistant NaOCl

Associated w/ failure of RCT

Question 9

Ideal characteristic irrigant?

Answer 9

Effective antimicrobial
Non irritating PA tissue
Active presence blood, serum
Not stain tooth
Doesn't induce immune response 
Able remove smear layer
Non toxic 
No adverse effect physical properties dentine 
Easy use
Inepxensive 
No adverse effect sealing ability materials

Question 10

Ideal way to prepare/clean canals?

Answer 10

Mechanical and chemical prep

Mechanical prep allows penetration irrigant to apical region

Question 11

Examples of irrigants currently used?

Answer 11

Sodium hypochlorite NaOCl
EDTA
CHX

Question 12

Advantage NaOCl?

Answer 12

Only one dissolves organic matter - biofilm
Antimicrobial
Cheap

Question 13

Issue NaOCL?

Answer 13

Dillute - larger volumes irrigant required

Question 14

Disadv NaOCL?

Answer 14

Doesn’t remove dentine debris/smear layer
Affect dentine properties
Rare case allergy
Toxic vital tissue

Question 15

Potential problems of using NaOCl?

Answer 15

Extrusion injuries

Damage to insturments

Question 16

What can EDTA be used for?

Answer 16

Removal of smear layer

Used for penultimate rinse

Question 17

What two irrigants should never be used together?

Answer 17

CHX and NaOCl
Forms brown precipitate - potentially carcinogenic
Need use saline in between

Question 18

Issue using iodine potassium iodide?

Answer 18

Allergic reaction iodine
Stain dentine
No tissue disolving
Unable remove smear layer

Question 19

How does hydrogen peroxide work?

Answer 19

Free radicals which destroy proteins and DNA

Question 20

Issue w/ hydrogen peroxide?

Answer 20

Can release 02 bubbles - can lead air emphysema

Question 21

What is MTAD?

Answer 21

Mixed tetracycline, acid and detergent

Question 22

Issue MTAD?

Answer 22

Expensive
Risk bacterial resistance
Tetracycline staining

Question 23

Current protocol for irrigating?

Answer 23

Use NaOCl throughout followed penultimate flush EDTA

NaOCl - removes organic
EDTA - removes smear layer

Question 24

What instrument can increase efficacy of irrigants?

Answer 24

Ultrasonic

Question 25

Disadv EDTA?

Answer 25

Limited properties as antimicrobial agent