08 irrigation

Question 1

What is the endodontic lubricant that we use in the VCU Undergraduate Endodontics Clinic?

Answer 1

RC Prep in our clinic

Question 2

Inadequate shaping of the root canal space leads to all of the following EXCEPT:
a.
Inadequate cleaning of the root canal space
b.
Inadequate sealing of the root canal space
c.

Inadequate removal of dentin
d.
Treatment failure

Answer 2

inad removal of dentin

Question 3

Which of the following is a DISADVANTAGE of using water as an irrigating solution?
a.

Water is non toxic.
	b. 	
Water does not remove the smear layer.
	c. 	
Water does not stain dentin.
	d. 	
Water does not flush debris from the canal.

Answer 3

water does not remove the smear layer

Question 4

What is the most popular irrigating solution used in endodontiics?

Answer 4

NaOCl

-alternative is Chlorhexidine

Question 5

What is the concentration of NaOCl used in the Undergraduate Endodontics Clinic at VCU?

Answer 5

2.6%

Question 6

What is the advantage of using a safety tip needle when irrigating a root canal?

Answer 6

It helps prevent extrusion of the solution from the apex of the canal.

Question 7

Which component of the smear layer is removed by EDTA?

Answer 7

inorganic

Question 8

How long is EDTA left in the tooth in order to remove smear layer?

Answer 8

one minute

Question 9

Which of the following are disadvantages of chlorhexidine?

Answer 9

Chlorhexidine is expensive.

Chlorhexidine does not disolve tissue.

Question 10

Statement 1: RC Prep is used with hand files.

Statement 2: RC Prep is used with rotary files.

Answer 10

first statement=true

second statement=false

Question 11

Objectives of Shaping

Answer 11

• Provide better access for the cleaning and
irrigating the canal space.
• Create a tapered preparation to facilitate obturation (sealing of the canal system).

Question 12

Failure to achieve shaping objectives

Answer 12

• Leads to:
– Inadequate cleaning of the root canal space
– Inadequate obturation (sealing of the root canal space.
– Treatment failure

Question 13

• A canal cannot be instrumented dry because it would:

Answer 13

1. Create dust and chunks of dentin that would clog the canal space.
2. Create frictional heat.

Question 14

Working in a Wet Environment

Answer 14

• Flushes and Floats debris from the canal space

* Cools instruments working in the canal space

Question 15

Ideal Properties of an Irrigating Solution

Answer 15

• dissolve vital and necrotic pulp tissue
• antimicrobial
• lubricates
• low surface tension
• removes biofilm
• removes smear layer
• readily available
• inexpensive
• adequate shelf life
• non-staining

Question 16

safest irrigating agent

Answer 16

water or saline
-cheap, non-toxic, non-staining
• Is not antimicrobial, does not dissolve tissue, has no effect on smear layer

Question 17

Most Popular Agent for irrigation

Answer 17

• Sodium Hypochlorite (NaOCl,Commercial Bleach)

Question 18

what are the effective concentrations of NaOCl used, and what does VCU use?

Answer 18

-6 or 5.25% (full strength commercial bleach)
-3 or 2.6% (half strength)
VCU uses 2.6%

Question 19

what are the advantages and disadvantages of NaOCl for irrigation?

Answer 19

– Advantages
• antimicrobial
• dissolves vital and necrotic pulp tissue • inexpensive and readily available
• removes organic portion of smear layer
– Disadvantages
• toxic to vital tissue
• dangerous if extruded from canal space

Question 20

alternative agent for NaOCl:

Answer 20

• 2% Chlorhexidine (Peridex is 0.12%)
• Effective antimicrobial
• Sometimes mixed with surfactant to reduce surface tension
• Low to moderate toxicity
• Does not dissolve tissue
• Expensive

Question 21

the smear layer has organic and inorganic portions, what is the most effect for removing the organic and inorganic portions respectively?

Answer 21

NaOCl (organic)

-17% EDTA for non-organic

Question 22

Clinic Protocol: Irrigation

Answer 22

• Half Strength NaOCl as Primary Irrigant
• 17% EDTA as final irrigant for 1 minute prior to obturation
• Flush with saline
• Final irrigation with 2% Chlorhexidine for 1 minute

Question 23

what irrigants should NOT BE MIXED?

Answer 23

• NaOCl with 2% Chlorhexidine – forms brown precipitate (parachloroaniline) which is potentially carcinogenic
• EDTA with 2% Chlorhexidine- forms white precipitate (salt) which is harmless

Question 24

what are the ways that irrigation can be inhanced?

Answer 24

• Heating NaOCl (controversial)
• Sonic Activation (controversial)
• Ultrasonic Activation (proven)
• Negative Pressure (new)(endo-vac)

Question 25

when are lubricants used?

Answer 25

only with hand files,

Question 26

what lubricant is used at VCU?

what is it made of and what does it do?

Answer 26

RC prep (15% EDTA, 10% urea peroxide)
-Acts as chelating agent