endodontic irrigation

Irrigation in Endodontics

Dr.Mohamed Ali Alazrak BDS.MScTripoli Medical Center – [email protected]

Introduction

•Every root canal system has spaces that can not be cleaned mechanichally .

•The only way to clean webs, fins and anastomoses is through effective use of irrigation solution.

•in order to get the maximum efficiency from irrigant , irrigant must reach the apical portion of the canal .

Anti microbial properties

Tissue solvent.

Flush debris.

Lubricant.

Eliminate the smear layer.

Low toxicity level

Properties of ideal irrigant solution

COMMONLY USED

IRRIGATING SOLUTIONS

I.Chemically non active solution:

Water.

Saline.

Anesthesia.

I.Chemically non active solution: Anti microbial properties

Tissue solvent.

Flush debris.

Lubricant.


Low toxicity level

II.Chemically active materials :

•Alkalis : sodium hypochlorite

•Antibacterial agents : chlorhexidin

•Oxidizing agents: hydrogen prioxide

•Chelating agents: EDTA ( ethylene diamine tetra acetic acid)

Sodium hypochlorite (NaOcl)Clear ,pale green-yellow liquid

with strong odor of chlorine.

It is a potent antimicrobial

agent, killing most bacteria

instantly on direct contact. It

also effectively dissolves

necrotic and vital pulp tissue.The most advocated irrigant,inexpensive and readily available.

Sodium hypochlorite (NaOcl)


Tissue solvent. ( dissolve vital and non vital tissue)

Flush debris.

Lubricant.


Low toxicity level.

Mechanism of action Sodium hypochlorite (NaOCl) ionizes in water into

Na and the hypochlorite ion, OCl, establishing an

equilibrium with hypochlorous acid (HOCl).

Hypochlorous acid is responsible for the

antibacterial activity; the OCl ion is less effective

than the undissolved HOCl.

Hypochloric acid disrupts several vital functions of

the microbial cell, resulting in cell death.

Mechanism of action

At acidic and neutral pH, chlorine exists

predominantly as HOCl, whereas at high pH of 9 and

above, OCl predominates.

Concentration NaOCl is commonly used in concentrations

between 0.5% and 5%.

According to several studies The lower and higher

concentrations are equally efficient in reducing the

number of bacteria in infected root canals.

The time needed to inhibit bacterial growth and

tissue dissolving effect of NaOcl irrigant are related

to it is concentration ,but so is it is toxicity.

Increasing the temperature of hypochlorite irrigant to 600C, significantly increased its antimicrobial and tissue-dissolving effects.

Temperature

Limitation : Unpleasant taste

Relative toxicity

Inability to remove smear layer

Sodium hypochloride accident

Immediate severe pain for

2-6 minutes .immediate edema in adjacent

soft tissue because of perfusion

to the loose connective tissue.Extension of edema to a large

site of the face such as cheeks,

peri- orbital region, or lips.Ecchymosis on skin or mucosa

as a result of profuse interstitial

bleeding.


Managementinform the patient about the

cause and nature of the

complication.Immediately irrigate with normal

saline to decrease the soft-tissue

irritation by diluting the NaOCl.Let the bleeding response

continue as it helps to flush the

irritant out of the tissues.


Recommend ice bag compresses

for 24 hours (15-minute

intervals)to minimize swelling.Recommend warm, moist

compresses after 24 hours (15-

minute intervals).pain control with strong

analgesics for 3 to 7 days


Prophylactic antibiotic coverage

for 7 to 10 days to prevent

secondary infection or spreading of

the present infection.

Chlorhexidine (CHX)

Strong base, most stable in form of its salt …Chlorohexdin gluconate.

It possesses a broad-spectrum antimicrobial action and a relative absence of toxicity.

CHX lacks the tissue-dissolving ability.


(broad spctrum antimicrobial

agent )

Tissue solvent.

Flush debris.

Lubricant.


Low toxicity level.

Chlorhexidine (CHX)

Mechanism of action It penetrates the cell wall and attacks the bacterial

cytoplasmic or inner membrane or the yeast plasma

membrane.

In addtion chlorhexidin has property of substantivity

(residual effect).

Concentration 0.2% is concentration commonly used for chemically plaque

control in oral cavity .

2% is concentration used as root canal irrigation.

Limitation Unable to dissolve remaining necrotic tissue.

Less effective on gram negative than on gram positive.

Unable to remove smear layer.

Hydrogen Peroxide H2O2

It is a clear, colorless,odorless

liquid.

H2O2 is active against viruses,

bacteria, and yeasts.

It has been particularly popular

in cleaning the pulp chamber

from blood and tissue remnants,

but it has also been used in

canal irrigation.

Hydrogen Peroxide H2O2


(broad spctrum antimicrobial

agent )

Tissue solvent.

Flush debris.

Lubricant.


Low toxicity level.

Mechanism of action It is highly unstable and easily decomposed by heat and

light.

it rapidly dissociate into H2O+O (water+nascent oxygen)

. the liberated O has bacteriocidal effect but this effect is

transient and diminishes in presence of organic debris .

The rapid release of O nascent oxygen on contact with

organic tissue results in effervesce (bubbling) action

which aid in mechanical debridement by dislodging

dentin debris and necrotic tissue particles and floating

them to the surface.

Concentration

It is recommended to use in

3% conentration for

endodontic irrigation.

Advantages of using alternating 3% H2O2 with Naocl

solution are :

1.Effervescent reaction (bubbles pushes debris

mechanichally out of root canal)

2.Solvent action of sodium hypochrorite on organic

debris.

3.Disinfection and bleaching effect by both solutions.

Limitation Unable to remove smear layer.

Always use Naocl last because Hydrogen peroxide

release of nascent oxygen on contact with organic

tissue which may build up pressure on closing tooth

and causes pain .

• Soft tissue emphysema may occur when hydrogen

peroxide irrigant enforced beyond the apical

foramen.

MTAD

A mixture of tetracycline isomer, acid, and detergent.

(doxycycline, citric acid, and the detergent Tween-80)


(broad spctrum antimicrobial agent )

Tissue solvent.

Flush debris.

Lubricant.


Low toxicity level.

Advantges1) it is an effective solution for removal of most of smear

layer.

2) Antibactrial effect ( kill most significant bacterial

strains i.e. E faecalis which has been shown to resist to

many intracanal medicament and irrigants.).

3) It is biocompatible .

4) The high binding affinity of doxycycline present in

MTAD for dentin allows prolonged antibacterial effect.

(substantivity)

Chelating Agents

EDTA (ethylene-diaminetetra-aceticacid)

The basic purpose of

chelating agent is lubrication

,emulsification and holding

debris in suspension .

Mechanism of action

•E

DTA functions by forming

calcium chelate solution with

calcium ions of dentin which

make it more friable and thus

dentin become easily to

manipulate by instrumentation.

EDTA

17% EDTA ( pH 7 )

EDTA has no antibacterial activity.

It effectively removes smear layer by

chelating the inorganic component of

the dentine.

Aid in mechanical canal shaping.

T

he optimal working time of EDTA is 15 minutes, after which

time no more chelating action can be expected.

Smear Layer T

he smear layer is a layer of debris ,compromising both

organic and inorganic components, found on canal walls

after endodontic instrumentation, it is typically 1-2 um in

thick .

I

t is made up largely of particularly dentin debris removed

by endodontic instrument during canal preparation but may

also contains remnants of pulp tissue and microorganisms.

Smear Layer P

resence of smear layer on the canal walls potentially

interfere with the adaptation of sealer against canal

wall and may create avenue of leakage of

microorganisms by act as substrate for microbial

proliferation .

Smear layer removal Can be accomplished by one of the following ways :

1)Use of chelating agents (17% EDTA) during the

cleaning and shaping . Upon complete the root canal

shaping soak the canal for 1 minute with liquid

EDTA , then rinse the canal thoroughly with NaOcl .

2)After irrigation with NaOcl Soak the canal for a 5

minutes with MTAD as final irrigant.

Dry canal with paper points, so the it is now ready

for obturation .

Irrigation

technique and devices

① Plastic syringe with needles

•Plastic syringes of different sizes (1–20 mL) are most commonly used for irrigation .

•All syringes for endodontic irrigation must have a Luer-Lock design.

Types of endodntic needles

1) Beveled needle:

Needle with bevel if get lodged

into canal there is a risk of

forcing irrigant beyond the

apex.

Types of endodntic needles :

2) Monoject irrigating needle:

Monoject endodontic needles to

be the most efficient delivery

system in which longer

needles of a blunted, open-

end system were inserted to

the full length of the canal to

ensure optimum cleaning.

A larger volume of solution can

be delivered by this method.

3) Max-i-Probe irrigating needle :

It has closed-end and side window.

This design allow for upward

flushing action for better canal

irrigation and also eliminates

possibilities of irrigant to be pushed

beyond the apical foramen.

Irrigation method: I

t is strongly recommended that the needle lie passively in the canal and not engage the walls.

A 27- or 30-gauge needle is preferred

The solution must be introduced slowly.

The irrigating needle should be bent to allow easier delivery of the solution and to prevent deep penetration of the needle.

Care must be taken with irrigants like sodium hypochlorite to prevent accidents.

② Gutta-percha Points agitation

• u

se of apically fitting gutta-

percha cone in an up-and-down

motion at the working length.

Although this facilitates the

exchange of the apical solution,

but the overall volume of fresh

solution in the apical canal is

likely to remain small.

③ EndoActivator

•I

t is based on sonic vibration

(up to 10,000 rpm) of a

plastic tip in the root canal.

The system has 3 different

sizes of tips that are easily

attached to the battery

operated handpiece that

creates the sonic vibrations.

③ EndoActivator

•i

t allow more irrigant

penetration and mechanical

cleansing compared with

needle irrigation, with no

increase in the risk of irrigant

extrusion through the apex.

④ Ultrasound

•U

ltrasound is sound energy with frequency

above 25 KHZ.

• P

assive ultrasonic irrigation have shown to clean

root canals or eliminate bacteria from the walls

better than conventional methods.

Mechanism of action

•W

hen a small file (size 10-20) is

placed freely in the center of the

canal following preparation and

ultrsonic activation is given .

The ulrtasonic energy passage

through irrigating solution and

exerts its (acoustic streaming

effect ).

Mechanism of action

•T

his mechanichal energy warms

the irrigant solution (NaOcl) and

dislodge debris from canals.

•T

he combination of activation

and heating the irrigation

solution is adjunct in cleaning

the root canal system .

⑤ EndoVac•T

he EndoVac system is based on

a negative-pressure

approach whereby the irrigant

placed in the pulp chamber is sucked

down the root canal and back up

again through a thin needle with a

special design.

Advantges :1) the EndoVac system lowers the

risks associated with irrigation

close to the apical foramen .

2) good apical cleaning at the 1-mm

level can be achieved by

reversed flow of irrigants and a

strong antibacterial effect when

hypochlorite is used.

Thank you

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endodontic irrigation

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