This document provides an overview of root canal disinfection and irrigation. It discusses the ideal requirements of irrigants including antimicrobial activity, flushing ability, non-toxicity, tissue dissolving ability, and smear layer removal. It categorizes common irrigants such as sodium hypochlorite, EDTA, and chlorhexidine and describes their mechanisms of action and limitations. Guidelines for irrigation techniques including manual, sonic, and laser-activated methods are also outlined.

1. Disinfection of root canal
GUIDED BY DR HEMANT VAGARALLI
PRESENTED BY DR ASHA K

2. CONTENTS
• Introduction
• Definition
• Objectives
• Ideal requirements of irrigants
• Classification of irrigants
• Sodium hypochlorite (NaOCl)
oMOA
oProperties
oAdverse effects

3. oToxicity
oManagement
oAdvantages
oDisadvantages
• Hydrogen peroxide
• Urea peroxide
• Ethylenediaminetetraacetic Acid (EDTA)
oMOA
• Chlorhexidine Digluconate (CHX 2%)
oMOA
oLimitations

4. • Other Irrigants
oHEBP
oIodine Potassium Iodide (IKI)
• Antibiotic-Containing Irrigants
oMTAD
oTetraclean
oQMiX
• Intracanal medicaments – calcium hydroxide
• Chlorhexidine
• Formaldehyde
• Halogens
• TAP

5. PART -2
• Irrigation guidelines
• Irrigant activation/agitation:
1. MANUAL
• Syringe irrigation with needles
• Brushes
• Manual dynamic agitation
2. MACHINE ASSISTED
• Rotary brushes
• Continuous irrigation during instrumentation
• Sonic irrigation

6. • Ultrasonic irrigation
oContinuous ultrasonic irrigation (CUI)
oPassive ultrasonic irrigation (PUI)
• Pressure alternation devices
oEndovac
oRinsendo
• Laser-activated irrigation: Photon-induced
photoacoustic streaming (PIPS)
• Wide-spectrum sound energy
• Conclusion
• References

7. INTRODUCTION
• Disinfectant is defined as an agent that destroys or
inhibits the activity of microorganisms that cause
disease.
• Irrigation is defined as to wash out a body cavity or
wound with water or a medicated fluid
Cohen 10th edition

8. • The primary goals of endodontic treatment are to
debride and disinfect the root canal space to the
greatest possible extent and to seal the root canal
system as effectively as possible, aiming to establish
or maintain healthy periapical tissues.
Endodontic irrigation , Bettina Basrani

9. • Cleaning and shaping of the root canal system though is
able to reduce the number of bacteria, complete
disinfection of the canal is difficult because of internal
complexity of the root canal system.
• Most endodontic failures is likely caused by the inability to
eliminate bacteria from the root canal system.

10. • Investigators have shown many factors which
attribute to internal complexity of the canals:
• multiple foramina,
• additional canals,
• fins, deltas, inter-canal connections,
• ‘C-shaped’ canals and
• accessory canals

11. • Studies have demonstrated that
mechanical instrumentation cannot
sufficiently disinfect root canals
regardless of the instrumentation
technique or system used.
• Despite technological advances in the
ability to shape root canals, at least 35%
of root canal surfaces still remain
uninstrumented.
• Thus a root canal irrigant is imperative
to aid in the disinfection of the canals
completely.
In vitro efficacy of a non-instrumentation technique to remove intracanal multispecies
biofilm, Ronald et . al , JOE 2021

12. • The choice of an irrigating solution for use in
infected root canals requires previous knowledge of
the microorganism responsible for the infectious
process as well as the properties of different
irrigating solutions.

13. Objectives of irrigation
• Mechanical and chemical functions:
• Flushing
• Lubrication
• Dissolution
• Smear layer removal
• Biological functions:
• Antimicrobial

14. Ideal requirements
• Antimicrobial activity
• Mechanically flushes out the debris from the root canal
• Nontoxic and nonirritating to the periapical tissues
• Dissolves necrotic and vital pulp tissues
• Serves as a lubricant
• Removes the smear layer
• Low surface tension
Grossman 13th edition

15. Irrigating solutions for endodontic use must meet
precise requirements:
a) they must be able to digest proteins and dissolve necrotic tissue
b) they must have a low surface tension to reach the apical delta and
all the areas that cannot be reached by the instruments
c) they must have germicidal and antibacterial properties
d) they must be non-toxic and non-irritating to the periapical tissues
e) they must keep the dentinal debris in suspension
f) they must lubricate the canal instruments
g) they must prevent discoloration of the tooth; indeed, they should
bleach the tooth
h) they must be relatively harmless to the patient and dentist
i) they must be readily available and inexpensive.
- Castellucci vol 2

17. Classification
Most commonly used irrigants
 Sodium hypochlorite (NaOCl)
 Ethylenediaminetetraacetic acid (EDTA)
 Chlorhexidine digluconate (CHX)
Other recently introduced irrigants
 1 – hydroxyethylidene – 1 , 1-bisphosphonate ( HEBP)
 Iodine potassium iodide (IKI)
Antibiotic containing irrigants
 MTAD
 Tetraclean
 QMix Grossman 14th edition

18. Irrigants
Chemical
agents
Tissue
dissolving
agents
Ex: NaOCl,
ClO2
Antibacteria
l agents
Bactericidal
Ex: CHX
Bacteriostatic
Ex: MTAD
Chelating
agents
Mild pH
Ex: HEBP
Strong pH
Ex: EDTA
Natural
agents
Antibacterial
agents
Ex: Green
tea, Triphala
Root canal irrigants: Journal of Conservative Dentistry (2010)

19. Normal saline
• Normal saline causes gross debridement and
lubrication of root canals.
• Very mild in action - used as an adjunct to
chemical irrigant.
• Normal saline as 0.9%W/V is commonly used
as irrigant in endodontics.
• It basically acts by flushing action.
• It can also be used as final rinse for root canals
to remove any chemical irrigant left after root
canal preparation.

21. Sodium hypochlorite
• Sodium hypochlorite (NaOCl), a
reducing agent, is a clear, straw-
colored solution.
• Most widely used irrigating solution
History:
• First produced in 1789 in France
• Was used as a hospital antiseptic that
was sold under the trade names Eusol
and Dakin’s solution

22. In 1919 , Coolidge introduced NaOCl to endodontics as
an intracanal irrigant solution

23. Mechanism of action
According to Estrela et al., the mechanism of action
of sodium hypochlorite occurs due to the following
properties and interactions:
• Saponification reaction
• Amino acid neutralization
• Hypochlorous acid formation
• Chloramination reaction
• High alkaline pH >11

24. - Cohen 12th edition

25. Tissue dissolution ability
• NaOCl posses strong tissue dissolution property
• The solvent action of NaOCl has been attributed to
its high alkalinity
• It depends on its concentration, temperature & time
of application.
• Grossman and Meiman reported that 5% sodium
hypochlorite dissolves pulp tissue in 20 min to 2 h

27. Various concentrations
• There has been much controversy over the
appropriate concentration of hypochlorite solutions
to be used in endodontics
• As Dakin's original 0.5% sodium hypochlorite
solution was designed to treat open (burnt) wounds
• It was surmised that in the confined area of a root
canal system, higher concentrations should be used ,
as they would be more efficient than Dakin's solution

28. • NaOCl has been used in various concentrations ranging
from 0.5- 5.25%
• ADA (American Dental Association) accepted
concentration for clinical use of NaOCl as an irrigant is
5.25% (Cunningham et al. 1980).
• Most commonly used concentration - 2.5%
• The antibacterial effectiveness and tissue dissolving
capacity of NaOCl is a function of its concentration but
so is its toxicity

29. • The lower and higher concentrations are equally efficient
in reducing the number of bacteria in infected root canal
• But the tissue dissolving effect is directly related to the
concentration
Baumgartner and Cuenin commented that-
The effectiveness of low concentrations of NaOCl may be
improved by using larger volumes of irrigant and
replenishing fresh solutions into the canal more frequently

30. • 1% and 5% NaOCl was used

31. Effect of temperature:
• There are various devices to preheat NaOCl syringes
however, it was demonstrated that as soon as the
irrigant touches the root canal system, the
temperature reaches the body temperature.
• Increasing the temperature of low-concentration
NaOCl solutions improves their immediate tissue-
dissolution capacity

32. • Therefore, some authors recommend in-situ heating of
NaOCl. This can be done by activating ultrasonic or sonic
tips to the NaOCl inside the root canal for a couple of
minutes
• Macedo and colleagues stated that the efficacy of NaOCl on
dentin is improved by refreshment, ultrasonic activation, and
exposure time
• In this investigation, a 10° C temperature rise during
ultrasonic activation was insufficient to increase the reaction
rate
• However, no clinical studies are available to support the use
of heated NaOCl.

33. • A 100- fold increase in killing efficacy of E.feacalis
was observed between the corresponding NaOCl
solutions at 20°C and 45°C in a study conducted by
George et al(2005)

34. Bleaching action of NaOCl:
• Satisfies the need to use an irrigating solution that
prevents discoloration of the tooth and may help to
bleach them
• Commercially sold bleaching agent (Household
purposes) – 5.25% NaOCl
• Schilder described bleaching activity as passive and
esthetic
• Coolidge attributed the bleaching ability to the
oxidizing activity of NaOCl

35. Adverse Effects of NaOCl:
1. Effect on physical properties of dentin
2. Influence of NaOCl on Endodontic Instruments
3. NaOCl toxicity
4. Damage to eyes
5. Damage to clothing
6. NaOCl accidents – Apical Extrusion
7. Allergic reactions to NaOCl

36. Effect on physical properties of
dentin
• NaOCl is an efficient organic solvent that causes dentin
degeneration because of the dissolution of collagen by the
breakdown of the bonds between carbon atoms and
disorganization of the proteic primary structure.
Effect of NaOCl treatment on bonding to root canal dentin
using a new evaluation method. Dent Mater J. 2001
• The reduction of the bond strength seen between adhesive
systems and dentin walls may be because of the removal of
collagen fibrils from the dentin surface by NaOCl,
impeding the formation of a consistent hybrid layer
Bond strengths to endodontically-treated teeth. Am J Dent.
1999

37. Effect on resin bonding:
• The reduction of the bond strength seen between
adhesive systems and dentin walls may be because of the
removal of collagen fibrils from the dentin surface by
NaOCl, impeding the formation of a consistent hybrid
layer.
• It requires a use of a reversal agent (ascorbic acid or
sodium ascorbate) because of its ability to affect the
polymerization of the resin sealer
A Contemporary Overview of Endodontic Irrigants – A
Review – Journal of Dental Applications 2014

38. Influence of NaOCl on
Endodontic files:
• Corrosion adversely affects the metallic surfaces by
causing pitting and porosity
• It is supposed that these microstructural defects can
lead to areas of stress collection and crack formation,
weakening the structure of the instrument (Oshida et
al. 1992).
• Decreases the cutting efficiency of endodontic files
(Stokes et al. 1999)

40. • Busslinger and Barbakow evaluated corrosion of
NiTi endodontic files caused by NaOCl solutions of
different concentrations from 0.5% to 5.5%
• These authors concluded that the quantities of ions
released by the corrosion process into the NaOCl
solutions were insignificant
• Fabiola et al. suggests that exposure to 5.25%
NaOCl solution affects neither resistance to flexural
fatigue nor torsional resistance of NiTi K3
endodontic files.

41. 1. Interaction with CHX
• The reaction between NaOCl and CHX produces a
carcinogenic product - parachloroanaline (PCA)
• The presence of PCA was confirmed by the Beilstein
test for the presence of chlorine and the HCl
solubility test for the presence of aniline
• This reaction coats the canal surface and
significantly occludes the dentinal tubules and
affects the seal of the root canal

42. 2. Interaction with EDTA
• Grawehr concluded that EDTA retained its calcium
complexing ability when mixed with NaOCl, but
however it instantaneously reduces the amount of
chlorine of NaOCl & ultimately NaOCl loses its
tissue-dissolving capacity
• Short-term irrigation with hypochlorite after EDTA
at the end of chemomechanical preparation causes
strong erosion of the canal-wall surface dentin

43. 3. Interaction with H2O2
• Many clinicians mix NaOCl with hydrogen peroxide
for root canal irrigation
• Despite more vigorous bubbling, the effectiveness of
the mixture has not been shown to be better than that
of NaOCl alone

44. Advantages
• The ability of NaOCl to dissolve organic soft tissue of
the pulp
• It is well recognized to be effective against a broad
range of pathogens: gram-positive and gram-negative
bacteria, fungi, spores, and viruses including the human
immunodeficiency virus
• Gross debridement and flushing out of debris
• Removes smear layer when used with EDTA

45. Disadvantages
• Acute inflammation followed by necrosis results
when NaOCl comes into contact with vital tissue -
when extrude out of the apical foramen
• Hypersensitivity - irritation to eyes
• May crystallize on the root canal walls
Effect on physical properties:
• Degraded by light, air, and contaminants- hence to
use fresh solution always

46. NaOCl Toxicity:
• A 1% concentration of NaOCl provides sufficient
tissue dissolution and antimicrobial effect, but the
concentration used has been as high as 5.25%
because of enhanced anti-microbial activity
(Yesilsoy et al. 1995).
• As the concentration used rises so does its toxicity.
• Numerous reports have described clinical
complications because of the improper use of NaOCl

47. • Sodium hypochlorite is a cytotoxic agent (Gatot et al.
1991, Gernhardt et al. 2004).
• When it comes into contact with vital tissue, it causes
• haemolysis,
• ulceration,
• inhibits neutrophil migration
• and damages endothelial and fibroblast cells (Gatot et
al.1991)
• It has a pH of approximately 11–12 and causes injury
primarily by oxidation of proteins (Kaufman & Keila
1989, Gatot et al. 1991, Serper et al. 2004)

48. Damage to the eye
• Irrigant in contact with the patient’s or operator’s
eyes results in immediate pain, profuse watering,
intense burning, and erythema.
Management
• Immediate ocular irrigation with large amounts of
tap water or sterile saline should be performed by the
dentist
• The patient should be referred to an ophthalmologist
for further examination and treatment (Ingram 1990).

49. Damage to clothing:
• Probably the most common incidents during root
canal irrigation concern damage of the patients’
clothing.
Prevention
• By proper protection of the patients clothing.
• When using hand irrigation, one should assure that
the irrigation needle and syringe are securely
attached.

50. NaOCl Accidents:
Occurrence:
• when the apical constriction has been destroyed
during root canal preparation or by resorption.
• may occur in teeth with wide apical foramina
• extreme pressure during irrigation
• binding of the irrigation needle tip in the root canal
The excellent tissue-dissolving capability of sodium
hypochlorite will lead to tissue necrosis.

51. Symptomatology
Pain
• Immediate severe pain ( 2-6 minutes)
Oedema
• Immediate oedema of neighbouring soft tissues
• Possible extension of oedema over the injured half
• side of the face, upper lip, infraorbital region

54. Modern Endodontic Principles Part 4: Irrigation ,James Darcey

55. Chlorhexidine digluconate
• Cationic bisbiguanide
• pH of 5.5 – 7
• Structure consists of two symmetric four-
chlorophenyl rings and two bisguanide groups held
together by a central hexamethylene chain

56. Various concentrations
• Available as - 0.12%, 0.2%, 2%
• Commercially available oral rinse
typically contains 0.12% CHX
gluconate
• 0.12% CHX has been found to be
ineffective for endodontic use
whereas concentrations above it
have been successfully used
• Available in both gel and liquid
formulations

57. Mechanism of action

58. Antibacterial activity
• It has a wide antimicrobial spectrum and is effective
against both Gram-positive and Gram -ve bacteria as
well as yeasts, while bacterial spores are resistant to
CHX
• Possesses greater efficacy towards Gram +ve
bacteria
• Low concentrations - bacteriostatic
• High concentrations - bactericidal
• CHX penetrates the cell wall and causes
precipitation or coagulation of cytoplasm probably
caused by cross linking

59. substantivity
• Clinically CHX’s substantivity seems to be an
advantage over NaOCl, sustaining the antimicrobial
activity over a period of 48 hours or 72 hrs after
treatment
• Their cationic properties also allow them to bind
electrostatically to surfaces
• They are gradually released from the surface, as the
concentration of chlorhexidine in the environment
decreases
• The reversible reaction of uptake and release of
CHX results in a substantive antibacterial activity

60. Interactions of CHX
1. CHX and dentin bonding (Anticollagenolytic
Activity):
• CHX is known to have a broad-spectrum MMP
inhibitory effect & so significantly improved the
integrity of the hybrid layer in a 6-month clinical
trial
• Adsorption of CHX by dentin improves the resin
infiltration in dentinal tubules and thereby increasing
bond strength

61. 2 . CHX and coronal microleakage:
• Canals medicated with CHX alone or in combination with
CHX retard the entrance of microorganisms through the
coronal portion of the tooth into the root canal system,
due to its wide antimicrobial activity and substantivity
• Such a finding is interesting, especially if the coronal
restoration becomes defective or if it is lost
3 . Allergic reactions of CHX:
• CHX may have a number of rare side effects, such as
desquamative gingivitis, discoloration of the teeth and
tongue, or dysgeusia

62. Biocompatibility
Various studies have shown that CHX has extremely
low level of tissue toxicity as compared to NaOCl ( as
low as 0.5%)
Limitations
• Inability to dissolve organic matter
• No action on smear layer

63. EDTA – Ethylene diamine tetra
acetic acid
Is a polycarboxylic aminoacid, colourless ,water
soluble solid
History:
• 1957- Nygaard Ostby recommended the use of 15%
EDTA solution (pH 7.3)
formula for 15% EDTA was:
• disodium salt of EDTA - 17.0 g
• distilled water - 100.00 ml
• 5N sodium hydroxide - 9.25 ml

64. • 1963 - A detergent was added to increase the cleaning and
bactericidal potential of EDTA
• The new composition being known as EDTAC which has
0.84g of quaternary ammonium compound - Cetavlon
• EDTAC reduced surface tension of the irrigant
facilitating wetting of the entire root canal wall thereby
increasing the ability of chelators to penetrate dentine
• It also had a greater anti-microbial effect than EDTA

65. • 1969- Strewart et al. introduced RC-Prep (Premier
Dental) paste type chelating agent
Recently paste type chelators have regained
popularity as almost all manufacturers of Ni-Ti
instruments recommend the use of EDTA as a
lubricant during rotary root canal preparation to
reduce the risk of instrument separation

66. Mechanism of action
• EDTA functions by forming a calcium–chelate
solution with the calcium ion of dentin
• The dentin thereby becomes more friable and easier
to instrument
• This solution removes the inorganic component of
the endodontic smear layer
• The smear layer is a combination of dentin, pulpal,
and bacterial debris

67. • On direct exposure for extended time, EDTA extracts
bacterial surface proteins by combining with metal ions from
the cell membrane which can eventually lead to bacterial
death.
• Chelators such as EDTA form a stable complex with
calcium. When all available ions have been bound,
equilibrium is formed and no further dissolution takes place.
• EDTA is self-limiting

68. Some clinicians advocate the removal of the
smear layer by irrigating the canal with sodium
hypochlorite followed by EDTA

69. The demineralizing action :
•Removes inorganic component of smear layer
•Reduces the time necessary for debridement
•Aides in enlarging narrow/ obstructed canals
•Helps bypass fragmented instruments
Changes in dentin permeability
After removal of smear layer with the aid of EDTA,
dentin permeability increased and reduction in micro
leakage between the definitive root canal filling and
canal wall was achieved

70. Clinical recommendations
• Root canal preparation can be carried out with the aid of
chelator paste.
• A chelator in paste form serves as a lubricant for files and
reduces the risk of instrument fracture in the canal.
• A final intensive rinse with 17% EDTA reduces the extent of
the smear layer remaining which in turn results in a cleaner
canal wall and better adaptation of the root fillings to the canal
walls
• EDTA containing agents should be used between 1-5 minutes

71. Various Preparations:
 Liquid chelators:
Calcinase
• Contains 17% Sodium edetate, sodium
hydroxide as a stabilizer and purified
water.
REDTA (Roth International)
• has 17% EDTA solution with addition of
0.84g Cetrimide to reduce the surface
tension.

72. EDTA-t
• Contains 17% EDTA+ Sodium lauryl
ether sulfate (Tergentol) as a detergent.
Largal ultra (septodent)
• contains 15% EDTA,
• 0.75% cetrimide
• pH value 7.4

73.  Paste chelators:
These paste chelators are the one most commonly
recommended with rotary instrumentation
Calcinase slide:
• it contains 15% sodium EDTA
• 58 to 60% water.
• has alkaline pH value of 8.9
• it is water soluble hence easily rinsed from root canal
system
• The gel is firm at room temperature and develops a
creamy consistency when agitated

74. RC-PREP
• It contains 15% EDTA,
• 10% Urea peroxide and
• Glycol in aqueous ointment base .
• Oxygen is set free by reaction of
NaOCl with RC-Prep resulting in
effervescence, so that pulpal remnants
and blood coagulates can be easily
removed from the root canal wall
(Stewart et al)
• Glycol acts as a lubricant

75. Glyde file
• Is composed of 15% EDTA
• 10% Urea peroxide in aqueous solution
• It has got properties similar to RC-Prep
FileCare EDTA
• Also composed of 15% EDTA
• 10% urea peroxide
File EZE
• Contains 19% EDTA

76. Hydroxyethylidene bisphosphonate
(HEBP)
• Also known as etidronic acid or etidronate
• Weak chelator and a potential alternative to
EDTA
• It has no short term reactivity with NaOCl
• Can be used in combination with NaOCl
without affecting its proteolytic or
antimicrobial properties
• Studies have shown that HEBP prevents
bone resorption and is used systemically in
patients suffering from osteoporosis or
Paget’s disease

77. Ruddle solution
• Hypaque is a high contrast radiopaque & injectable
dye.
• It is water soluble with pH of 6.7- 7.7
• This composition simultaneously provides the
solvent action of full-strength NaOCl, visualization,
& improved penetration
• Used to visualize the microanatomy, verify the
shape, monitor the remaining root wall thickness

78. Hydrogen peroxide
• H2O2 is a widely used biocide for
disinfection and sterilization
• It is a clear, colorless liquid that is used in
a variety of concentrations in dentistry,
ranging from 1% to 30%
• It degrades into water and oxygen
• H2O2 is active against viruses, bacteria,
yeasts, and even bacterial spores

79. Mechanism of action:
• It is highly unstable and easily decomposed by heat
and light
• It rapidly dissociates into water and nascent oxygen
• On coming in contact with tissue enzymes catalase
and peroxidase , the liberated [O] produces
bactericidal effect but this effect is transient and
diminishes in presence of organic debris
• It causes oxidation of bacterial sulfhydryl group of
enzymes and thus interferes with bacterial
metabolism

80. • The rapid release of nascent oxygen on contact with
organic tissue results in bubbling action which is
thought to aid in mechanical debridement by dislodging
particles of necrotic tissue and dentinal debris and
floating them to the surface
• Moller recommended 30% H2O2 as the first step in
tooth surface disinfection
• It has been particularly popular in cleaning the pulp
chamber from blood and tissue remnants, it has also
been used in canal irrigation

81. • For years 3% H2O2 has been recommended as a
canal irrigant because of its effervescent action in
presence of blood products
Effervescent action:
• This action was specially indicated in mandibular
teeth where the bubbling of the peroxide was thought
to lift debris from the canal system.
• However, H2O2 does not possess tissue dissolution
properties and is not effective as a lubricant
• Hence, alternate use of H202 + NaOCl irrigating
solutions was recommended by Grossman.

82. Injection of hydrogen peroxide beyond
apex
• Bhat (1974) reported a case in which hydrogen
peroxide of unknown concentration was injected into
the soft tissues due to lateral perforation of right
maxillary central incisor
• Patient experienced no pain under L.A but
complained about a rapidly developing swelling on
the upper lip and some difficulty in breathing
• The canal was left open, the patient was prescribed
antibiotics and instructed to apply cold packs
• The emphysema, caused by oxygen liberated from
the hydrogen peroxide, subsided in 1 week and root
canal treatment was completed IEJ 2000

83. Disadvantage
• It does not possess tissue dissolving property
• Not a lubricant
• Limited antimicrobial action
• Complication
• Peroxide must be eliminated from the canal before
the crown is sealed otherwise oxygen may be
evolved afterwards as a result of contact with blood
or tissue fluids

84. Urea peroxide
• Urea peroxide (Endo-PTC or Gly-Oxide) is another
widely used solution to aid instrumentation
Mechanism of action
• Produces hydroxyl radicals that oxidises sulphydryl
groups, double bonds in proteins, lipid and outer
membranes - cause cell death
• It retains its antibacterial activity in the presence of
blood whereas aqueous 3% hydrogen peroxide does
not

85. Iodine potassium iodide (IKI)
• IKI is a broad-spectrum antimicrobial
irrigant used in a concentration of 2–
5% in endodontics
• A potential disadvantage of iodine-
containing irrigants is a possible
allergic reaction in some patients.

86. Citric acid
• Available in 10-50% concentration
• Demineralizing solution that is used during the
endodontic therapy to remove the smear layer from the
prepared root canal
• Citric acid interferes with the mechanism of action of
NaOCl
• Citric acid 10% is more biocompatible and effective in
removing smear layer than 17% of EDTA

87. Maleic acid
• Acid conditioner in adhesive dentistry at
5-7% conc.
• Final irrigation with 7% of maleic acid is
more efficient than 17% of EDTA in the
removal of smear layer from the apical
third of the root canal.
• 7% of maleic acid produces greater
surface roughness on root canal walls as
compared to 17% of EDTA
• This surface roughness provides an
important role in micromechanical
bonding of resin sealers

88. MTAD

89. • Combined chelating and antibacterial properties
• Clinically effective
• Biocompatible
• Citric acid may serve to remove the smear layer,
allowing doxycycline to enter the dentinal tubules and
exert an antibacterial effect
• Removes smear layer while being less erosive
• Potential sustained antibacterial activity
Final rinse
• The recently revised protocol for clinical use of MTAD
advises an initial irrigation for 20 min with 1.3% NaOCl,
followed by a 5-min final rinse with MTAD

90. Tetraclean
• Tetraclean like MTAD, is mixture of an Citric Acid,
doxycycline, and a detergent
• However, the concentration of the antibiotic
(doxycycline-50 mg/ml), and the type of detergent
(polypropylene glycol) differ from those of MTAD
• Tetraclean is a mixture of doxycycline hyclate (at a
lower concentration than in MTAD), an acid, and a
detergent
• They do not dissolve organic tissue and are intended
for use at the end of chemomechanical preparation
after sodium hypochlorite

91. Antimicrobial action
• It shows a high action against both, strictly anaerobic
and facultative anaerobic bacteria
• It is also more effective than MTAD against E.
faecalis in planktonic culture and in mixed species in
vitro biofilm
Smear layer
• It is able to eliminate microorganisms and smear
layer in dentinal tubules of infected root canals with
a final 5-min rinse.
Surface tension
• It has low surface tension which enables a better
adaptation of the mixtures to the dentinal walls

92. QMix
• It is a combination of 17% edta and 2%
chloorhexidine
• Q mix is an irrigation solution used as a final rinse

93. Triclosan and gantrez
• Triclosan is a broad spectrum antimicrobial agent
• Active against G+ and G- bacteria, some fungi and
viruses
• Nudera et al. evaluated minimum bactericidal
concentrations (MBC) of triclosan and triclosan with
Gantrez against P intermedia, F nucleatum, A naeslundii,
P gingivalis, and E faecalis
• The MBC of triclosan ranged from 12–94 μg/ml
• The MBC of triclosan with Gantrez ranged from <0.3–
10.4 μg/ml
• The addition of Gantrez enhanced the bactericidal activity
of triclosan

94. Electrochemically activated water
• Russian scientists have developed a process whereby
so-called electro-chemically activated water (ECA)
is produced with a new and unique anode–cathode
system (Leonov 1997)
• ECA is produced from tap water and saline solution
by a special unit that houses a unique flow-through
electrolytic module (FEM)

95. To obtain the best end solutions with the ECA, NaCI water
solutions with no more than 5.0 g/L concentration or fresh
water of less than 1.0 g/L mineralization is needed

96. • The FEM contains the
Anode
• made from titanium and coated
with ruthenium-oxide, iridium
and Platinum
Cathode
• made from titanium coated with
pyro carbon and glass carbon
• the anode being a solid cylinder
fits coaxially inside the cathode
which is a hollow cylinder
Membrane
• Made up of ceramic in between
them

97. • The physical and chemical nature of ECA is not yet fully
understood
• The solution supposedly exists in a metastable or dis
equilibrious state for 48 h after production and contains
many free radicals and a variety of molecules
• After 48h the solution returns to the stable state, becoming
inactive again
• In the metastable state the solutions have a very high
oxidation reduction potential

98. An in vitro study of comparative evaluation
of efficacy of electrochemically activated
water as a root canal irrigant in smear layer
removal
• Results: NaOCl, maleic acid, and ECA had similar
smear layer removal efficacy. MTAD was less
efficient than the other irrigants tested. Saline did not
remove the smear layer.
• Conclusion: Electrochemically activated water has
promising smear layer removal efficacy and is
comparable with conventional root canal irrigants.
•. 2020 Sep-Oct;23(5):447-450. doi: 10.4103/JCD.JCD_488_20. Epub 2021 Feb 10

99. Evaluation of the Antibacterial Efficacy
of QMix and AgNP Solutions in Root
Canals of Primary Molars: An In-Vitro
Study
Dania et al 2022
• Results - Sodium hypochlorite, AgNPs, and QMix 2in1
effectively reduced the bacterial count of Enterococcus
within root canals of primary molars. There were statistical
differences between all groups. QMix 2in1 solution showed
the greatest antibacterial efficacy, then NaOCl solution and
AgNPs solution.

103. Irrigation devices
…………….to be continued

104. Formocresol
• Formocresol, which is categorized into
the aldehydes, has been used
extensively in endodontic therapy
• Buckley referred to it as an effective
intracanal medicament in 1904
• Formaldehyde is volatile and releases
antimicrobial vapors when applied to a
cotton pellet for the disinfection of pulp
chamber

105. Calcium hydroxide
• Calcium hydroxide is the most commonly used
intracanal medicament
• It is highly alkaline with a pH of approximately
12.5 which prevents the growth and survival of
bacteria , most of which cannot survive pH11 or
above

106. Mechanism of action

109. LIMITATIONS
• The handling and proper placement of calcium
hydroxide present a challenge to clinician.
• Also ,the removal of calcium hydroxide is frequently
incomplete ,resulting in a residue covering 20% to 45%
of the canal wall surfaces ,even after copious irrigation
with saline ,NaOCl / EDTA
• Most notably ,it may interfere with the seal of the root
filling and compromise the quality of treatment

110. • Recently the ability of calcium hydroxide to
completely eradicate bacteria from the root canal has
been questioned.
• Various invitro studies have shown that dentin can
inactivate the antibacterial activity of calcium
hydroxide

112. Phenols
• It is one of the oldest antimicrobial
agents used in medicine ,introduced by
Lord Lister in 1867
• It was used for many years for its
disinfectant and caustic action
• However it has strong inflammatory
potential.so, at present ,it is rarely used
as an intracanal medicament
• Liquefied phenol consist of 9 parts of
phenol and 1 part of water

113. Parachlorophenol
• It has been very popular component of
dressing , as phenol is no longer used in
endodontics because of its high toxicity to
efficacy ratio
COMPOSITION – this is substitution
product of phenol in which chlorine
replaces one of the hydrogen atoms.
Concentration – 1% aqueous solution is
preferred
Uses – used as an dressing of choice for
infected tooth

114. Camphorated parachlorophenol
• The camphor present in camphorated
parachlorophenol reduces irritating
effect of pure parachlorophenol and
acting as a diluent and vehicle.
• Grossman brought to light the
antimicrobial effect of camphorated
parachlorophenol compared to some
other root canal medicaments

115. Camphorated
monoparachlorophenol (CMCP)
2 parts of parachlorophenol +3 parts gum
camphor
Camphorated monochlorophenol(CMCP)

116. Triple antibiotic paste (TAP)
• The efficacy of triple antibiotic paste for
elimination of bacteria was first discussed
by Hoshino et al.(1996)
• The combination consists of metronidazole,
ciprofloxacin and minocycline
• Triple antibiotic powder, either mixed with
normal saline or 2% chlorhexidine,
produced the largest zone of inhibition
against E. faecalis
• DRAWBACK – antibacterial resistance

117. Polyantibiotic
paste (PBSC)
PBSN

118. Novel and Advanced Disinfection
Therapies
Nanoparticles
Nanoparticles measure between 1 and 100 nm
Silver nanoparticles are the most widely
investigated metallic nanoparticle in the field of root
canal disinfection
A study found that a silver nanoparticle-based
irrigant had antibiofilm activity comparable to 2%
chlorhexidine and 5% sodium hypochlorite
Drawback – dentin discoration , cytotoxic

119. Chitosan nanoparticle
• Derived from chitin, a natural component found in
shrimp and crab shells
• Chitosan nanoparticles exhibit excellent
biocompatibility as well as promising antibiofilm
and antimicrobial properties
• Chitosan nanoparticles were found to potently kill
planktonic and biofilm E. faecalis cells
• Chitosan nanoparticles have also been functionalized
with photosensitizers such as Rose Bengal and
methylene blue to enhance antibiofilm efficacy via
photodynamic activation

120. Calcium hydroxide
nanoparticles
• Developed to improve its diffusivity and
antibacterial activity
• Studies have reported that nanocalcium hydroxide
was able to penetrate deeper into dentinal tubules
and was more effective against E. faecalis compared
to conventional calcium hydroxide
• Mesoporous calcium silicate nanoparticles combined
with silver nanoparticles were able to inhibit the
growth of both planktonic and biofilm forms of E.
faecalis

121. Antimicrobial Peptides
• Antimicrobial peptides have recently gained
attention for their potential therapeutic applications
in disinfection.
• These peptides disrupt and destabilize the bacterial
membrane integrity and cellular functions,
eventually leading to cell death.
• This enables their broad-spectrum antimicrobial
activity including drug-resistant strains
(Present status and future directions of intracanal medicaments, Ronald et al
IEJ 2022)

122. Disinfectant devices and
techniques

124. Syringe irrigation with needles
• Regardless of the delivery system,
• the solution must be introduced slowly
• the needle never wedged in the canal
• As a rule, the clinician should irrigate copiously,
recapitulate and continue
Gauge of the needle
• Gauges ranging from standard 22 to finer 30 have been
used in endodontic irrigation.

126. • It should be bent approximately 30º in the center of
the needle to allow easier delivery of the solution
and to prevent deep penetration of the needle or
probe

127. Using a forefinger to
depress the plunger gives
greater control of irrigant
delivery

128. Stropko irrigator
• It consists of an adapter that connects to the air /
water syringe and accepts standard luerlock needle
tips for irrigant removal and application.
• As well as air drying

129. Manual brushes
• These are adjunctive aids in canal
debridement or agitation of
irrigants.
• The bristles help in cleaning the
uninstrumented recesses of the
radicular pulp space.
• Examples include the Endobrush
and NaviTip FX

130. Rotary brushes
• Advancement in small wire technology, bristle
materials and bristle attaching techniques have
enabled the creation of an endodontic microbrush of
clinical field testing
• They consist of microbrushes attached to rotary
handpieces, ex: CanalBrush, Ruddle Brush
• The brush includes a shaft or shank and a tapered
brush section .

132. Manual dynamic agitation
• An irrigant must be in direct contact
with the canal walls for effective action.
• Its often difficult for the irrigant to reach
the apical portion of the canal because
of the so-called vapor lock effect
• The gently moving well-fitting gutta-
percha master cone up and down in
short 2 to 3 mm strokes within an
instrumented canal
• Can produce an effective hydrodynamic
effect and significantly improve the
displacement and exchange of any given
reagent

133. Apical vapor lock
• Definition: Air entrapment at the apical
part of root canal during syringe irrigation
and totally block irrigant penetration in
that area, a phenomenon also termed apical
vapor lock (Bettina basrani et al)
• NaOCl reacts with organic material in the
root canal and quickly forms micro air
bubbles at the apical third that coalesce
into an apical vapor lock with subsequent
instrumentation

134. Problems of apical vapor lock:
• Prevents the flow of irrigant into the apical region
• Prevents adequate debridement of the canal system
How to overcome the vapor lock?
• Manual-dynamic irrigation: Hand-activated (moving
up & down) well-fitting gutta-percha master cone
that is introduced to working length after
instrumentation
• Apical negative pressure irrigation, such as EndoVac

135. Continuous irrigation during
instrumentation
Quantec E System:
• It uses a pump console, 2 irrigation
reservoirs and tubing
• It provides continuous irrigation
during rotary instrumentation
• Increased volume of irrigant
• Cleaner canal walls in the coronal
third (setlock et al ,walters et al)
Disadvantage: No significant cleaning
efficiency in middle and apical third

136. Sonic irrigation
• Sonic instruments was introduced by Tronstad et al
in 1985.
• It works in lower frequency (1–6 kHz) and produces
smaller shear stresses than ultrasonic irrigation
• Ex: Vibringe system , Endo Activator System

137. Endo activator system
• Handpiece: Cordless, portable, battery operated
• Polymer tips: Disposable (single use), smooth non-
cutting, radiolucent, strong & flexible
• Agitate irrigant solutions, provides 10,000 cpm /min
• It removes the smear layer, debride the uninstrumented
portion of the root canal system, and dislodge the biofilm
within long, narrow, and highly curved canal of molar
teeth.

138. Ultrasonic irrigation
• Richman (1967) introduced ultrasonics in
endodontics
• Ultrasonic irrigation modality operates at frequencies
of 25–30 kHz setting up transverse vibrations with a
characteristic pattern of nodes and antinode
Types:
1. Continuous ultrasonic irrigation (CUI)
2. Passive ultrasonic irrigation (PUI)

139. Continuous ultrasonic irrigation
(CUI)
• 25-gauge irrigation needle is used instead of an endosonic file.
• Irrigant is carried out from intravenous tubing connected via a
Luer-lok to an irrigation delivering syringe.
• Irrigant is delivered in apical one third by continuous flow.

140. Passive ultrasonic irrigation (PUI)
• Weller et al. in 1980
• Energy is transmitted from a file or smooth
oscillating wire to the irrigant by means of ultrasonic
waves that induce two physical phenomena:
Acoustic streaming
Cavitation

141. Acoustic streaming
• Acoustic streaming is the rapid movement of
fluid in a circular or vortex-like motion around
a vibrating object
• The acoustic streaming that occurs in the root
canal during ultrasonic irrigation has been
described as acoustic micro streaming
• The shear flow caused by acoustic
microstreaming produces shear stresses along
the root canal wall, which can remove debris
and bacteria from the wall

142. Cavitation
• Acoustic cavitation can be defined as the
creation of new bubbles or the expansion,
contraction and/or distortion of pre-
existing bubbles (so-called nuclei) in a
liquid, the process being coupled to
acoustic energy (Leighton 1994)
• These bubbles expand and then rapidly
collapse producing a focus of energy

143. Application of irrigant during PUI
• Two flushing methods can be used during PUI,
namely a continuous flush of irrigant from the
ultrasonic handpiece or an intermittent flush method
using syringe delivery(Cameron 1988)
• Both flushing methods were equally effective in
removing dentine debris from the root canal in an ex
vivo model when the irrigation time was set at 3 min
(van der Sluis et al. 2006)

144. 1. REMOVAL OF SMEAR LAYER:
• PUI is more effective than syringe needle irrigation in
removing pulpal tissue remnants and dentin debris
• Smear layers were effectively removed from the apical,
middle, and cervical thirds of the canal walls by Cetavlon
(EDTAC) and NaOCl by using a size 15 file energized by
ultrasonic agitation
2. REMOVAL OF BACTERIA:
• High-power ultrasound causes de-agglomeration of
bacterial biofilms via the action of acoustic streaming
• Cavitation may produce temporary weakening of the cell
membrane

145. Safety Irrigator
• Is an irrigation /evacuation system that apically
delivers the irrigant under positive pressure through
a thin needle containing a lateral opening and
evacuates the solution through a large needle at root
canal orifices

146. • The safety irrigator features a large coronal
evacuation tube ,enabling the user to safely irrigate
and evacuate simultaneously
• It was designed to limit risk of NaOCl accidents
• This technique produces better cleaning efficacy
than syringe irrigation but significantly worse than
MDA with a tapered cone

147. Pressure alteration devices
EndoVac System:
• Apical negative pressure irrigation system
• It uses suction technique to wash out the debris and
encourage the flow of irrigation in apical two third of
the canal
• Composed of three basic components:
1. Master Delivery Tip (MDT)
2. Macrocannula
3. Microcannula

149. MDT - The manufacturer’s instructions
must be followed for correct use of the
Master Delivery Tip and to avoid creation
of positive pressure in the pulp canal
• The flow of irrigant from the MDT should
always be directed into an axial wall or the
wall of pulp chamber and never directly
into an orifice

150. Macro-cannula is plastic with an
open end that measures size 55
with a 0.02 taper.
• Following complete
instrumentation, the
macrocannula is used in each
canal for 30 s in a short up-and-
down pecking motion as close
as possible to working length

151. Micro-cannula - is stainless steel and has 12 small,
laterally positioned, offset holes in 4 rows of 3, with a
closed end measuring ISO size 30.
• The micro-cannula can be used at working length in a
canal enlarged to ISO size 35 or larger

152. Rins Endo:
• Rins Endo was introduced by Durr
Dental Co
• Based on pressure suction
technology with aproximately 100
cycles per minute
• Its components are a handpiece, a
cannula with a 7 mm exit aperture,
and a syringe carrying irrigant.
Disadvantage:
• Higher risk of apical extrusion of
irrigant (McGill et al.)

153. Ozone
• Occurs as ozonated water, ozonated olive oil and
oxygen/ozone gas
• Antiseptic, powerful oxidant, and antibacterial agent
• Unstable - cannot be bottled, must be generated fresh
when needed
• Half-life - 40 minutes

154. • It is unstable and dissociates readily
back into oxygen (O2), thus liberating
so-called singlet oxygen (O1), which is
a strong oxidizing agent which further
impose the deleterious effect on
microorganisms
• Nagayoshi et al. found that ozonated
water (0.5–4 mg/L) was highly
effective in killing both gram positive
and negative micro-organisms

155. • Ozone is applied from the access opening, making
the technical realization a simple process
• There are five differently sized silicone cups
available to enable perfect tooth sealing
Inserting the
ozone cannula into
the prepared root
canal
Treatment with
ozone with a
complete seal

156. Limitations
Irritating to respiratory system
 At very low conc. (0.2–0.5 ppm) - headache,
irritation or dryness of the nose, throat and
eyes (McDonnell et al. 1983)
 At higher conc. (1–10 ppm over a few hours) -
lung congestion, oedema, hemorrhage,
changes to the blood and loss of vital lung
capacity
Irritating to the eyes - redness, pain and blurred
vision

157. Multisonic ultracleaning system
• GentleWave consists of a central unit from
which high-pressure pumps send high-speed
degassed irrigants to a special handpiece with
the tip of the handpiece placed into the pulp
chamber of the tooth.
• . It operates using a handpiece but no
component of this is placed within the canal
system .

158. • The instrument is placed over the pulp chamber,
sealing the tooth from the oral cavity and is activated
from a computer console.
• From this a spray of irrigant is delivered at 45 ml/
min at 40 °C.

159. Lasers
• Lasers have been studied for their ability to clean
and effectively disinfect the root canals.
• Provides greater accessibility of formerly
unreachable parts of the tubular network due to their
better penetration into dentinal tissues
• Scientific research was first conducted with the Nd:
YAG and the diode lasers which gained widespread
acceptance in the fields of laser assisted endodontics

160. • In various laser systems used in dentistry, the emitted
energy can be delivered into the root canal system by
Thin optical fiber
• Nd:YAG
• Er,Cr:YSGG
• Argon
• Diode
• Hollow tube
• CO2
• Er:YAG

161. Photon induced photoacoustic
streaming (PIPS)
• PIPS employs a erbium laser to pulse
extremely low energy levels of laser
light to create photoacoustic
shockwaves throughout the entire root
canal system without enlarging the
root canals
• The PIPS tip is placed in the pulp
chamber only and not in the canals
• The PIPS tapered tip creates a pressure
wave that streams irrigants throughout
the root canal system

162. Limitations
• Impossible to obtain uniform coverage of the canal
surface using a laser making complete removal of
smear layer and debris difficult
• Investigators strongly recommended improving the
endodontic tip to enable irradiation of all areas of the
root canal walls
• Another limitation is the safety of such a procedure
because thermal damage to the periapical tissues
potentially is possible

163. Photo activated disinfection (PAD)
• Also known as photodynamic
therapy(PDT)
• Is based on the concept that a nontoxic,
photosensitizing agent known as
photosensitizer(PS) can be preferentially
localized in certain tissues and
• Subsequently activated by light of the
appropriate wavelength to generate
• Singlet oxygen and free radicals that are
cytotoxic to cells of the target tissues

166. How Does PAD Work?
• Same bacteria sample after photo activated disinfection
process showing disruption of membrane
Same bacteria
sample after photo
activated
disinfection process
showing disruption
of membrane
Bacteria
before photo
activated
disinfection

168. Advantages
• PAD can be applied effectively for killing gram-positive,
gram negative, aerobic and anaerobic bacteria - in fact, all
commonly encountered bacteria associated with dental
disease
• PAD can kill bacteria in complex biofilms, which are
typically resistant to the action of antimicrobial agents
• Photo activated disinfection overcomes the problems of
antibiotic resistance
• PAD does not pose any thermal risks due to the low
power of the PAD laser

169. Disadvantages
• At the concentration provided, PAD solution
produces no side effect other than
• A transient color change in the dentine on the surface
of the canal wall
• This is removed by the washing process with sterile
saline performed after disinfection of the canal

170. Efficacy of sonically,
ultrasonically and laser-activated
irrigation in removing a biofilm-
mimicking hydrogel from an isthmus
model
• Aim: To evaluate the efficacy of sonically,
ultrasonically and laser-activated irrigation (LAI) in
removing a biofilm-mimicking hydrogel from the
isthmus in a root canal mode
• Conclusions: Laser-activated irrigation and Eddy
resulted in the greatest hydrogel removal and
performed better than EA and UAI. The effect of
LAI was also not dependent on deep intracanal tip
placement.
•. 2019 Apr;52(4):515-523. doi: 10.1111/iej.13024. Epub 2018 Oct 29.

171. Comparison of Vibringe,
EndoActivator, and needle
irrigation on sealer penetration
in extracted human teeth
• AIM - To compare the effect of different irrigation
systems on sealer penetration into dentinal tubules of
extracted single-rooted teeth.
• Conclusions: The use of sonic activation with either
the EndoActivator or Vibringe did not significantly
improve the sealer penetration when compared with
conventional irrigation.
•. 2013 May;39(5):708-11. doi: 10.1016/j.joen.2013.01.006. Epub 2013 Mar 7.

172. SUMMARY

180. Irrigation guidelines
• Solution should be introduced slowly and passively
into the canal
• Needle should never be wedged into the canal and
should allow an adequate backflow
• Blunted needle of 26 gauge or 27 gauge are
preferred
• In case of small canals, deposit the solution in pulp
chamber. Then file carries the solution into the canal.
Capillary action of narrow canal will stain the
solution

181. • To remove the excess fluid, either the aspirating syringe
or 2 × 2 inches folded gauge pad is placed near the
chamber
• In case of large canals, tip of needle should be introduced
until resistance is felt, then withdraw the needle 2–3 mm
away from that point and irrigate the canal passively
• In order to clean effectively in both anterior and posterior
teeth canals, a blunt bend of 30° in the center of needle
can be given to reach the optimum length to the canal
• Volume of irrigant is more important than concentration
or type of irrigant

182. CONCLUSION
• Instrumentation of the root canal system must
always be supported by an irrigation system capable
of removing pulp tissue remnants and dentin debris
• Liberal amounts of irrigation are essential for the
effective function of the files
• A variety of chemical agents in fluid form and
sometimes in viscous preparation has been used to
aid canal preparation and irrigation
• Selection and use of the correct irrigant for the
different clinical situations will help to achieve
predictable endodontic success

183. • Future research on irrigants needs to focus on
finding a single irrigant that has tissue dissolving
capacity, smear layer removal property, and
antibacterial efficacy.

184. References
• Pathways of the pulp – Cohen 11th edition
• Grossman’s Endodontic Practice – 14th edition
• Ingle’s Endodontics – 7th edition
• Endodontics – Vol II – Arnold Castellucci
• Agrawal Vineet S, Rajesh M, Sonali K, Mukesh P. A
contemporary overview of endodontic irrigants–A
review. J Dent App. 2014 Oct;1(6):105-5

185. • Napte B, Srinidhi SR. Endodontic irrigants. Journal of
Dental and Allied Sciences. 2015 Jan 1;4(1):25
• Zehnder M. Root canal irrigants. Journal of endodontics.
2006 May 1;32(5):389-98
• Estrela C, Estrela CR, Barbin EL, Spanó JC, Marchesan
MA, Pécora JD. Mechanism of action of sodium
hypochlorite. Brazilian dental journal. 2002;13(2):113-7
• Hülsmann M, Hahn W. Complications during root canal
irrigation–literature review and case reports. International
endodontic journal. 2000 May;33(3):186-93
• Gulabivala K, Patel B, Evans G, Ng YL. Effects of
mechanical and chemical procedures on root canal
surfaces. Endodontic Topics. 2005 Mar;10(1):103-22