This document discusses root canal irrigants. It begins by outlining the objectives and functions of irrigants, which include removing tissue, microorganisms, and debris from the root canal. It describes the ideal requirements for an irrigant and commonly used irrigating solutions such as sodium hypochlorite, hydrogen peroxide, chlorhexidine, and chelating agents like EDTA. The mechanisms of action, advantages, and disadvantages of different irrigants are provided. Factors that influence irrigant activity and how to increase the efficacy and safely use sodium hypochlorite are also summarized.

1. ROOT CANAL IRRIGANTS

2. SPECIFIC LEARNING OBJECTIVES
• To know the requirements and function of
irrigants.
• To know commonly used irrigants.
• To know the mechanism of action and specific
uses of these irrigants.

3. Introduction
• The goal of instrumentation and irrigation is to
remove all necrotic and vital organic tissue, as well as
some hard tissue, from the root canal system.
• Biological point of view, the key objective of
instrumentation and irrigation is to remove and
eradicate the microorganisms residing in the necrotic
root canal system.
• The use of irrigating solutions is an important part of
endodontic treatment.
• The irrigants facilitate the removal of necrotic tissue,
microorganisms, and dentin chips from the root canal
by a flushing action
• Irrigants can also help prevent packing infected hard
and soft tissue apically in the root canal and into the
periapical area.

4. Ideal requirements for an irrigation
• Have broad spectrum antimicrobial properties
• Help in debridement of the canal system
• Ability to dissolve necrotic tissue and debris
• Have low toxicity level
• Be a good lubricant
• Have low surface tension ,so it flows easily into inaccessible areas
• Effectively disinfect the root canal
• Inactivate endotoxin
• Be bactericidal
• Be fungicidal
• Not weaken tooth structure
• Cost effective and easily available
• Have adequate shelf life

5. Functions of Irrigants
• Remove dentinal shavings by physical flushing
• Increase the efficiency of instruments
• Dissolve necrotic tissue
• Remove debris from lateral and accessory canals
• Germicidal and antibacterial property
• Bleaching action
• Opening of dentinal tubules by removing smear
layer

6. FACTORS THAT MODIFY ACTIVITY OF IRRIGANTS
• Concentration of irrigant
• The length of time of contact
• Quantity of irrigant used
• The type and gauge of irrigating needle
• The surface tension of irrigation solution
• Temperature of the irrigant
• Frequency of irrigation
• Canal diameter
Benefits of Using Irrigants in Root Canal Treatment
• Removal of particulate debris and wetting of the canal walls
• Destruction of microorganisms
• Dissolution of organic debris
• Opening of dentinal tubules by removal of the smear layer
• Disinfection and cleaning of areas inaccessible to endodontic
instruments

7. COMMONLY USED IRRIGATING SOLUTIONS
Chemically non active solution;
• Water
• Saline
• Local anaesthetic
Chemically active materials;
• Alkaline; Sodium hypochlorite 0.5% - 6 %
• Chelating agents; Ethylene diamine tetraacetic acid (EDTA) 17%
,
• Oxidizing agents; Hydrogen peroxide, carbamide peroxide
• Antibacterial agents; Chlorhexidine 2%
• Acids; 30% hydrochloric acid, 50% citric acid, 40% polyacrylic
acid

8. NORMAL SALINE
Used as an adjunct to chemical irrigant
• Commonly used at 0.9%W/V
• Basically acts by flushing action
• Can used as a final rinse to remove chemical irritant after
preparation
ADVANTAGES;
• Biocompatible in nature
• No adverse effects if extruded periapically
• Osmotic pressure is same as that of blood.
Disadvantages;
• Do not have disinfecting and dissolving properties.
• Too mild
• Cannot clear microbial flora
• Do not have antimicrobial activity
• Do not remove smear layer

9. SODIUM HYPOCHLORITE
• Introduced by Henry Dakin also known DAKIN’s
solution.
• Walker suggested its use in root canal.
• Available in concentration of 0.5% to 6 %.
• Clear straw coloured solution
• Has a pH >11
• Commercially available as CLOROX
• Sodium hypochlorite (NaOCl) is the most widely used
irrigating solution in endodontics.
• It is a very potent antimicrobial agent and effectively
dissolves pulpal remnants and organic components of
dentin
• Sodium hypochlorite does not dissolve mineralized
tissue. This must be done either with EDTA, citric
acid, or some other chelators/acidic compounds

10. Methods to Increase Efficacy of Sodium Hypochlorite
• Time; antimicrobial effect is directly related to the contact time
in canal.
• Heat; warming to temp 21 to 37⁰C or upto 60⁰C increases tissue
dissolving properties.
• Specialized Irrigating Syringes ;
Irrigation requires at least a size no 30 at apex to reach apical
portion of canals.
Side venting syringes with narrower gauge (32),help in getting
irrigant closer to apex and move sideways.
• Ultrasonic activation ;
Help to accelerate chemical reaction, create cavitational effect
thus achieve superior cleansing action.

11. Precautions to be taken while using Sodium Hypochlorite
• Use of 6 % of NaOCL can cause serious damage to periapical tissue if
there is any mishaps .
• Higher concentrations of NaOCl are more toxic than lower
concentrations.
• If extruded can cause excruciating pain, periapical, bleeding and
swelling.
• Tissue destruction can cause spread of infection. Hence antibiotics,
analgesics and antihistamines should be prescribed.
• Reassure the patient
• Irrigate passively especially in cases with larger apices.
• Never lock the syringe into the canal.
• Naocl again after removing the smear layer with EDTA. However, when
used after a chelating agent or an acid, NaOCl causes erosion of the root
canal wall

12. DIFFERENT NEEDLE TIPS
30 GAUGE SAFETY NEEDLE
DEVICE FOR HEATING IRRIGANTS
SAFETY VENT

13. ENDOACTIVATOR FOR SONIC IRRIGATION
TOXIC EFFECT OF NaOCL ON
PERIRADICULAR TISSUE
ULTRASONIC
ACTIVATION OF
IRRIGANTS
FORCEFUL EXTRUSION OF IRRIGANTS

14. Advantages of using irrigation
• It causes tissue dissolution.
• Remove organic portion of dentin for deeper
penetration of medicaments.
• Removes biofilm.
• It causes dissolution of pulp and necrotic tissue.
• It has antibacterial and bleaching action.
• Causes lubrication of canals.
• Economical.
• Easily available.

15. Disadvantages of using irrigation
• Ability to wet dentin is less due to high surface
tension.
• Irritant to tissues and causes severe cellular
damage.
• Causes gingival inflammation
• Bleaches clothes if comes in contact.
• Has bad odor and taste.
• Vapours can irritate the eyes.
• Cause corrosion of instruments.
• Inability to remove smear layer.

16. Sodium Hypochlorite accident
Sodium Hypochlorite accident :Extrusion of sodium hypochlorite
into the periradicular area during root canal irrigation, causing
severe pain, swelling, ecchymosis and potential paresthesia.
Glossary Of Endodontic Terms 2019
Complication of extruded NaOCl through the apex :
• Severe pain,
• Edema of neighboring soft tissues,
• Possible extension of edema over the injured half of face and
upper lip,
• Profuse bleeding from root canal,
• Profuse interstitial bleeding with hemorrhage of skin and
mucosa (ecchymosis),
• Chlorine taste and irritation of throat after injection into
maxillary sinus,
• Secondary infection possible,
• Reversible anesthesia or paresthesia is possible.

17. Management Sodium Hypochlorite
accident
• To manage these lesions, the clinician should
inform the patient and control pain with local
anesthesia and analgesics. The application of
extraoral cold compresses to reduce swelling
is also effective. After 1 day, warm
compresses and frequent warm mouth rinses
for stimulation of local systemic circulation
should be used. Patients should be recalled
daily to monitor recovery.
• AB and antihistamine are not obligatory and
the use of corticosteroids is controversial.

18. HYDROGEN PEROXIDE
• Concentration is 1% to 30%
• It is clear, odorless
• It is more effective against Gram-positive than Gram-
negative bacteria
• Mechanism of action; It rapidly dissociates into H₂O +
(O) i e, ( water and nascent oxygen).
• 2 modes of action:
• Effervescence effect or bubbling action pushes out
dislodging particles of necrotic tissue and dentinal debris
onto the surface.
• Nascent oxygen destroys strictly anaerobic
microorganisms.
• Hydrogen peroxide is less effective as a solvent hence less
damage to periapical tissue.

19. CHLORHEXIDINE
• It has strong base in the form of salts i.e. chlorhexidine
gluconate.
• It is a potent antiseptic solution used in oral cavity in
concentration of 0.2%.
• It has optimal antimicrobial action between pH 5.5 and 7.
• Used as an irrigant at concentration of 2%
• it completely lacks tissue-dissolving capability that is an
important reason for the popularity of NaOCl
• CHX does not have a bad smell, it is not irritating to
periapical tissues, and it does not cause spot bleaching of
patients’ clothes.
• its substantivity (long-term continued effect)
• CHX is effective against both Gram-positive and Gram-
negative bacteria as well as yeasts, although the activity
against Gram-negative bacteria is not as good as against
Gram-positive bacteria.

20. Mechanism of Action
• It is a broad spectrum antimicrobial agent.
• The cationic molecule is absorbed into
• negatively charged inner cell membrane
causing leakage of intracellular components.
• At low concentration acts as bacteriostatic and
at higher concentration causes coagulation
and precipitation of cytoplasm and acts as
bactericidal.
• More effective against E.Faecalis.
• It has substantivity(residual effect), Has
microbial activity for 72 hrs or even up to 7
days as a endodontic irrigant.

21. Advantages;
• At 2% used as root irrigant.
• 0.2% used as mouth wash.
• More effective on gram-
positive bacteria than gram
negative bacteria.
• Used in combination with
calcium hydroxide as
intracanal medicament in
necrotic and retreatment
cases.
Disadvantages;
• Not considered as a main
irrigant in standard
endodontic therapy.
• It is unable to dissolve
necrotic tissue remnants.
• Less effective on gram-
negative bacteria.
• Does not show effect on
biofilms.

22. CHELATING AGENTS
• Defined as a chemical which combines with a metal to form
chelate.
• Most commonly used agents are;
1. EDTA
2. CITRIC ACID
3. POLYACRLYIC ACID
4. Mixture of tetracycline isomer, acid, and detergent (MTAD)
• AVAILABILTY
VISCOUS SUSPENSION
AQUEOUS SUSPENSION

23. EDTA
• Ethylene- diamine- tetra acetic acid .
• EDTA (17%, disodium salt, pH 7)
• Mechanism of action;
Forms a calcium chelate solution with the calcium ion of dentin,
Dentin thereby becomes more friable and easier to instrument.
• Uses:
• Lubrication
• Holding debris in suspension
• Smear layer removal
• Opens dentinal tubules and facilitates other irrigants to penetrate.
• Enhances adaptation of root canal fillings to canal walls preventing
microleakage.
• Softens root canal dentin
• Beneficial in narrow and calcified canals

24. METHODS OF IRRIGATION
• The solution must be slowly and passively introduced into the canal.
• Needle should never be wedged into the canal and allow adequate
back flow
• In small canals deposit the solution in pulp chamber, the file will
carry the solution.
• For effective cleaning of apical area, canals must be enlarged to
size 30 or large.
• Irrigants must never be forced into apical tissue.
• For effective cleaning, solution should be in close proximity to the
material to be removed.
• In large canals needle should be kept 2 to 3 mm away from point of
resistance and then irrigated.
• Volume of irrigant is more important than concentration or type of
irrigant.

25. IRRIGATION TECHNIQUE
Disposable plastic syringes of 2.5 or 5 ml capacity with
25 or 27 gauge blunted needles are Useful
for endodontic Irrigation.

26. • The smaller syringe barrels (i.e. less than 10 ml) require
frequent refilling during the instrumentation phase of
therapy.
• Plastic syringes in the 10 to 20 ml range may offer the
best combination of sufficient solution volume and
ease of handling.
• The barrel tip should be a Leur Lok design , rather than friction
fit to prevent accidental needle dislodgement during irrigation.

27. • The needle should be bent to an obtuse angle, to reach
the canals of posterior as well as anterior teeth.
• The needle is inserted into the root canal so that it
does not bind.

28. Sufficient room between needle and canal wall allows
for the return flow of the solution and avoids forcing of
solution into the periapical tissue.
Irrigation needle gauge no 27 barely
Reaches middle third in enlarged canals
Irrigation needle gauge no 30 sideventing
Reaches apical third in enlarged canals

29. • In narrow root canals, the tip of the needle is
placed in the root canal and the irrigant is
discharged until it fills the pulp chamber.
• RETURN OF SOLUTION IS COLLECTED ON
- GAUGE PIECE
- ASPIRATED

30. • If needle does not bind, the solution should be
ejected from the syringe with little or
no pressure on the plunger.

31. • Drying should be done with absorbent points.
• Most of the residual irrigating solution may be
removed from the root canal by holding the
needle of the syringe in the canal and
withdrawing the plunger slowly.
• Compressed air must not be used for drying
the root canal because tissue emphysema
may result if an air bubble penetrates the
periapical tissue.

32. • DIFFERENT IRRIGATING NEEDLES USED
• BEVELED NEEDLE.
• MONOJECT TIP.
• SAFE ENDED TIP.
• BEVELLED NEEDLE:
• IN BEVELED NEEDLE IRRIGANT IS FORCED
APICALLY. THERE IS RISK OF EXTRUSION IF
NEEDLE BECOMES LODGED IN THE CANAL.

33. • MONOJECT TIPS:
ADVANTAGE OF PASSING IRRIGANT TO
THE SIDE.
• SAFE ENDED TIP:
BEST TIP ADVANTAGE OF PASSING
IRRIGANT TO THE SIDE.

34. Advanced Irrigating Needle
Max I Probe Needle
or
Pro Rinse

35. • Max I probe irrigates through
side vent and the apical end of
the probe is closed.
• It consists of 25, 28 and 30
gauge closed ended needles.
Advantages :
• Prevents accidental forcing of
irrigating solution into
periapical tissue

36. • Martin designed a commercial system harnessing the
ultrasonic energy for the preparation and cleaning the
root canal in 1976.
• This technique was termed
Endosonics.
Ultrasonics

37. ACTION OF ACOUSTIC STREAMIG
The acoustic streaming generated by the file help to reduce the
number of bacteria in the canal by removing the smear layer
and debris harboring bacteria, thereby facilitating their
mechanical removal.
Acoustic streaming Cavitation

38. SONIC IRRIGATION
• Better than syringe irrigation
• Works on sonic vibration with frequency of 1-8KHz
• Agitate irrigant inside root canal
• Enhanced cleaning of entire root canal including apical third
• Better flushing of debris

39. REFERENCES…….
Pathways of pulp 12th edition
Principles and Practice of endodontics 6th edition
Endodontic Therapy 6th edition
THANK YOU