1
Intracanal medicaments
Nilesh Deshpande
JR-II
Department of pediatric and preventive
dentistry
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INTRODUCTION
• An important objective of endodontic therapy is the removal
of necrotic infected pulp and dentinal debris from the root canal
system of infected or non-vital teeth.
• Failure to use an irrigating solution during BMP results in
considerable amount of debris to be left behind in the root
canal system ultimately leading to endodontic failure.
• Hence for obtaining an optimum level of disinfection of the
root canal system chemo-mechanical preparation is a must.
3
HISTORY
Prior to 1940’s Water was the most commonly used
irrigant as it was:
1.Readily available.
2.Inexpensive.
3.Provided a lubricating effect during instrumentation.
4
During 1940’s proteolytic enzymes like streptokinase,
streptodomase, papain, etc. were being used as irrigating
solutions because of their tissue dissolving property.
In 1943, Grossman introduced the concept of using
oxidizing agents as irrigants.
In 1945, Daniel formulated
comprising of a amino-acridine.
an
irrigating
solution
In 1970’s chelating agents were used increasingly
because of their biologically acceptable properties.
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IDEAL REQUIREMENTS
•It should be an effective germicide and fungicide.
•It should be non-irritating to the periapical tissues.
•It should remain stable in solution.
•It should have prolonged antimicrobial effect
•It should be active in the presence of blood, serum and
protein derivatives of tissues.
•It should have low surface tension.
•It should not interfere with repair of periapical tissues.
•It should not stain tooth structure
•It should not induce cell mediated immune response.
•It should be capable of inactivation in a culture medium.
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CATEGORIES OF USE
That is conditions or situations for which intracanal medicaments
have been advocated.
•Elimination microorganisms.
•Rendering contents of canal inert
•Prevention or control of post treatment pain
•Enhancing Anesthesia
•Control of persistent periapical abscess
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CLASSIFICATIONS
A. According to DCNA
1.
2.
3.
4.
5.
6.
7.
Phenolics
- Eugenol
- Camphorated monoparachlorophenol (CMCP)
- Parachlorophenol (PCP)
- Camphorated parachlorophenol (CPC)
- Metacresylacetate (Cresatin)
- Cresol
- Creosote (Beechwood)
- Thymol
Aldehydes
- Formocresol
- Glutaraldehyde
Halides
- Sodium hypochlorite
- Iodine
- Potassium iodide
Steroids
Calcium hydroxide
Antibiotics
Combinations
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B. According to Grossman
1. Essential oils
- Eugenol
2. Phenolic compound
- Phenol
- Para chlorophenol
- Camphorated para chlorophenol
- Formocresol
- Glutaraldehyde
- Cresatin
3. Halogens
- sodium hypochlorite
- Iodides
4. Quaternary Ammonium compounds
- 9-amino acridine
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INDIVIDUAL INTRACANAL
MEDICAMENTS
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Physiologic Saline
From a biological stand point, sterile normal saline is the best
irrigant to use because it causes.
I.Least apical tissue irritation or damage.
II.Biocompatible.
III.Least amount of cell lysis.
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Disadvantages:
Does not remove the smear layer.
Flushes out some of the superficial debris from the
root canal system.
Has poor antibacterial properties.
However irrigation followed by ultrasonic and sonic
instrumentation have been reported to be almost as
effective as 0.5 to 2.5% sodium hypochlorite irrigation
in reducing the number of bacteria in infected root
canals.
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Phenol
•It is the oldest compound for controlling microorganisms.
• It was introduced by Lord Lister in 1867.
•It is white crystalline substance, and has a characteristic odor
derived from coal tar.
•Phenol is a protoplasmic poison and produces necrosis of soft
tissues by its ability to penetrate and disrupt the cell wall of
bacteria and subsequently the protoplasm.
•Liquefied phenol consists of 9 parts of phenol and 1 part water.
•Highly effective in 1 to 2% concentration.
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Camphorated Phenol
• This contains 30% phenol, 60% camphor, 10% ethyl
alcohol.
•
It is the least toxic of the phenolic compounds.
•
It has excellent antimicrobial effect and also relieves pain.
•
Camphorating process aims at developing a less caustic
medicament as a result of the slow release of phenol.
•
Camphor serves as a vehicle and diluent.
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Monochlorophenol (MCP)
-It is a derivative of phenol and has three isomers of which
paramonochlorophenol is the most effective.
- Mono chlorophenol is more effective antiseptic and is also
more toxic than phenol.
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Camphorated Paramonochlorophenol
(CMPCP) (Developed by Walkhoff 1891)
- Contains :
35% monochlorophenol
65% camphor
- Its antimicrobial effect is good.
- Highly toxic to the tissues.
- It is used in the form of vapor forming intracanal
medicament. The vapors can pass through the apical
foramen.
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Formocresol
Developed by BUCKLEY in 1906
Contents :
19% formaldehyde
35% cresol
46% water
Glycerine.
or is a combination of formalin and cresol in the proportion of 1:2
Formocresol combines the protein - coagulating effect of
phenolic compounds with the alkylating effect of formaldehyde.
The bactericidal effect of formocresol is good at levels as low as
2%.
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It is a strong poison and causes widespread destruction
of living tissue followed by a persistent inflammatory
reaction.
Studies have reported that formocresol treated tissue
produced a cell mediated immune response.
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Glutaraldehyde
-It is a colorless slightly soluble in H2O.
-Slightly acidic
-It is a strong disinfectant and fixative
-Used in concentration of 2%
- Extent of toxicity is less compared to formaldehyde. Its molecular
weight is high compared to formaldehyde hence does not
penetrate into the periapical tissues.
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Glutaraldehyde was preferred to formaldehyde:
Irreversible bonding with proteins.
Limited diffusion into tooth structure.
No periapical irritation.
Appears to cause a softening of dentin for limited
duration, facilitating the mechanical preparation of the
root canal.
Greater reduction in microorganisms with
glutaraldehyde 2% can be attributed to the fixative
property rendering the microorganisms inert and nontoxic.
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Cresatin
Also known as metacresylacetate
It is a clear, stable, oily liquid of low volatility.
It has both antiseptic and obtundant properties
Compared to formocresol or camphorated parachlorophenol the
antimicrobial effect of cresatin is less
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Creosote
It is a mixture of phenol and phenol derivatives
Beachwood creosote has long been used in endodontic
therapy.
There are several reports on severe tissue irritation and
necrosis
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Alcohols
Ethyl alcohol and Isopropyl alcohol are used.
These denature protiens in high concentration.
Denaturing takes place in presence of water, hence 70%
is prefered to 95%
They are not recommended as intracanal medicament
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Eugenol
 It is the chemical essence of oil of clove.
 It is related to phenol
 It is both an antiseptic and an obtundant
 It is slightly more irritating than oil of clove.
Studies have reported that eugenol inhibited intradental nerve
impulses
 A few reports of allergy to eugenol have been reported.
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Heavy metal salts
Salts of silver, copper and mercury are used.
They coagulate protiens and act as enzyme inhibitors.
They are toxic.
The mercury salts are rendered less effective by the tissue fluid
proteins present in the root canal. Hence they are not often used.
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N2
Contains :
Paraformaldehyde
Phenylmercuric borate
Eugenol.
Additional
ingredients
like
lead,
corticosteroids, antibiotics.
It is claimed to be both intracanal medicament and a
sealer
Claims that N2 has a permanent disinfectant action
and unusual antimicrobial properties have been denied by
the council on Dental Therapeutics of the American Dental
Association.
The antibacterial effect of N2 is short lived about a
week to 10 days.
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SODIUM HYPOCHLORITE
Is one of the most popular irrigating solutions. It has been
used as an irrigant for well over 4 decades.
It was first recommended as an antiseptic solution by
HENRY DAKIN in 1915 and was called as DAKIN’s
SOLUTION during the time of World War-I (NaOCl buffered
with sodium bicarbonate).
0.5% NaOCl solution was then used as a treatment for
infected wounds.
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Manufactured:
It is made by bubbling chlorine gas through NaOH to
form equal amounts of sodium hypochlorite and sodium
chloride (NaOH  gas NaOCl + NaCl2)
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Properties of NaOCl:
Antibacterial action
Strong dissolution property:
Fresh tissue
Necrotic tissue
Fixed tissue
Lubricant – for effective instrumentation.
Bleaching action on discolored teeth.
NaOCl has been used in various concentrations ranging from
0.5-5.25%.
Most commonly used concentration – 2.5%
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ACTIONS:
Antibacterial:
NaOCl exerts its antibacterial action either by:
1.Direct contact with microorganisms.
2.Vapour action.
Destruction of the bacteria takes place in two phases:
•Penetration into the bacterial cell.
•Chemical combination with the protoplasm of the bacterial cell
that destroys it.
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Sodium hypochlorite at 5.25% is an extremely effective
antimicrobial agent.
Studies have shown that this solution will destroy most
of the microorganisms found in the root-canal system after
exposure of 1 minute or less.
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FACTORS AFFECTING THE ANTIMICROBIAL PROPERTIES
OF NaOCl:
•Diluting 5.25%
significantly.
NaOCl
inhibits
its
antimicrobial
property
•Bactericidal effectiveness of 5.25% NaOCl decreases over time.
Martin suggested a storage shelf-life of 3 months for undiluted
preparations.
•The antimicrobial property may be achieved in a significantly
lesser time by prewarming the solution (room temperature 22°Cbody temperature 37°C).
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•It maintains a remarkable degree of antimicrobial activity in
the presence of organic matter such as blood and serum
albumin.
** Briseno (1992) and coworkers demonstrated that the
irrigation of the root canal with 1% NaOCl (manual) was
more effective against the test organisms (E-edi +
S.mutans) than irrigation of the root canal with 2% NaOCl
+ ultrasound.
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TISSUE SOLVENT PROPERTY
NaOCl possesses strong tissue dissolution property for fresh
vital tissue, necrotic tissue and fixed tissues. This tissue
dissolving capacity equals to that shown by H2SO4 and HCl.
The solvent action of NaOCl has been attributed to its high
alkalinity.
The removal of organic tissue by NaOCl is by the release of
hypochlorous acid which reacts with insoluble proteins to form
soluble polypeptides, aminoacids and other by products.
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•NaOCl – hypochlorus acid + insoluble proteins – soluble
polypeptides, aminoacids and byproducts.
•Grossman has shown that it can dissolve an entire pulp in
20 minutes to 2 hours.
•5.25% of NaOCl is capable of penetrating into the dentinal
tubules and dissolving the contents of the tubules adjacent
to the main canal.
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NaOCl and Smear layers
NaOCl alone is not very effective in removal of the smear
layer, but when used in conjunction with other solutions or with
ultrasonics it has shown to remove the smear layer effectively.
Yamada and associates (2003) reported that a final
flushing of 17% EDTA, followed by 10ml of 5.25% NaOCl, was
more effective in removing both inorganic and organic debris.
These authors concluded, that flushing with a chelating agent
removed the final calcific sludge that remained on the canal walls.
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Flushing with 10ml NaOCl removed any remaining organic
tissue, thus leaving patent dentinal tubules on the surface of
the canal walls.
(Lengiz in 97) showed that the use of 0.5% NaOCl in
combination with Ca(OH)2 preparation and ultrasonics in the
root canal can effectively remove the smear layer.
Also this is considered to be more safer than the use of NaOCl
solution is 5% concentration which is proved to be highly
toxic.
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TOXICITY OF NaOCl TO PERIAPICAL TISSUE
Causes:
1.Severe pain.
2.Edema.
3.Profuse haemorrhage both interstitially and through the tooth.
This may be followed by (for several days)
1.Increasing edema.
2.Ecchymosis.
3.Tissue necrosis.
4.Parasthesia.
5.Secondary infection (rarely).
Majority of cases, have shown complete resolution within a couple of
weeks. In some cases they may be long-term parasthesia or scarring.
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Treatment
a) For immediate relief of pain – nerve block and L.A.
b) Wet, cold, compress – continually applied to the face – for
relief of pain and burning sensation and minimize swelling
(for upto 6 hours).
c) Analgesics – after emergency treatment.
d) To control inflammation – corticosteroids immediately i.v. for
3 days.
e) To prevent infection – antibiotics (1wk).
Heat packs and warm mouth rinse (after initial treatment).
To improve circulation to the area.
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Advise the patient concerning the anticipated swelling
and ecchymosis.
Give the patient both verbal and written instructions.
Reassure the patient that he will regain his normal
appearance within a short period.
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HYDROGEN PEROXIDE
3% H2O2 was recommended as a canal irrigant because of:
a) Its effervescent action.
b) Disinfecting properties.
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Effervescent action was specially indicated in mandibular teeth
where the bubbling of the peroxide was thought to lift debris
from the canal system almost defying gravity.
 H2O2 does not possess tissue dissolution properties
Not effective as a lubricant.
 Hence, alternate use of H2O2 + NaOCl irrigating solutions
was recommended by Grossman.
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This alternate irrigation regimen during Chemo-mechanical
preparation produces:
a) Transient but energetic effervescence that
mechanically forces out debris and microorganisms out
of the canal.
b) At the same time the O2 that is liberated in an active
state assists in destroying the anaerobic
microorganisms.
c) The permeability of dentinal tubules is increased
allowing deeper penetration of intracanal medicament.
d) Increases the bleaching action on discolored teeth.
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CHELATING AGENTS
Aid in the mechanical enlargement of difficult root canals by
softening the root canal dentin walls.
EDTA – Ethylene diamine tetra-acetic acid composed by
Disodium salt of EDTA distilled water 100ml, 5N NaOH 4.25ml.
This was 1st described for use in endodontics by Ostby.
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Functions
a) It has certain dentin dissolving effects desirable in all
kinds of root canal therapy – ease in instrumentation.
b) It reduced the time necessary for debridement and
disinfection.
c) It aided in enlarging narrow / obstructed canals.
d) It helped make possible the bypassing of broken
instruments in the canals.
e) Removed the inorganic component of smear layer.
f) Had no corrosive effects on the instruments.
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Action
The sodium salts of EDTA are capable of forming soluble
non-ionic chelates with large number of metallic ions viz. calcium
ions.
Because EDTA would seek the calcium metal ion in the
hydroxyapatite crystals of dentin in a chelate and thereby act to
demineralize dentin and enamel.
 Ostby and associates found that EDTA decalcified dentin to a
depth of 20-30µm in 5 minutes.
 Franklin et al in 2004 reported that it is possible to overchelate
a canal which can lead to perforation.
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EDTA is known to remain active within the canal for 5
days.
If not inactivated the solution may seep into the
periapical tissues and damage the bone.
Therefore at the completion of appointment, the canal
must be irrigated with NaOCl.
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RC Preparation
It’s a combination of 17% EDTA + urea peroxide 10%,
developed by Stewart and colleagues.
Effective lubricating and cleaning agent.
1.It allows deeper penetration of the medicament into the
dentin.
2.It is not water-soluble.
3.It is popularly used in combination with NaOCl.
4.Because it is thought to produce a bubbling action helps
loosen and float out dentinal debris.
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Studies have shown RC preparation might affect the apical
seal.
Cook and associates in 1998 reported twice as much
leakage in canals obturated with GP or silver cones
following cleaning and shaping with RC preparation
NaOCl than with NaOCl alone.
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EDTA-c (commercial name)
Quaternary ammonium compound to EDTA + Cetavlon which has
greater germicidal acitivity and disinfecting properties.
REDTA – A quaternary ammonium bromide + EDTA solution.
To reduce the surface tension + increase the permeability of the
solution.
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SALVIZOL
Another
chelating
agent
is
salvizol
based
on
aminoquinaldinum diacetate.
Properties:
•It has surface acting property similar to quaternary ammonium
groups.
•Chelating action.
•Organic debridement.
•Bactericidal activity.
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ORGANIC ACIDS
The use of organic acid irrigants to irrigate and debride root
canals is as old as root canal therapy itself.
CITRIC ACID:
Has been recommended as a canal irrigant because of its
ability to demineralize and remove the smear layer effectively.
2 observations were made:
•It acts as a chelating agent on dentine.
•Therefore, it occurs naturally in the body, it is more acceptable
biologically than other acids ((Jenkin and Dawer 1963).
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The chelating action of citric acid softens the dentin and facilitates
easy removal of the smear layer.
CA has been used effectively in concentration of 10, 25 and
50% as RC irrigant.
Disadvantages:
C.A. may leave precipitated crystals (calcium and
phosphate containing crystals) in the canal wall. Which may be a
disadvantage.
1.Citric acid has been used in combination with NaOCl to
effectively clean the R.C.
2.C.A. removes smear layer better than many acids like poly
acrylic acid, lactic acid and phosphoric acid.
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TANNIC ACID
Tannic acid is another cleansing agent for root canal
preparation was suggested by Graham Mount.
It has been extensively used in the treatment of burns
(more than 100 years old).
Action: It acts as a surface coagulant by precipitating
proteins.
*Studies have shown that the use of tannic acid in the root canal
as an irrigant cleansed the canal more effectively than the
conventional combination of NaOCl + H2O2.
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CHLORHEXIDINE GLUCONATE
Chlorhexidine has become recognized as an effective
antimicrobial agent and its use as a potential endodontic irrigant
has been demonstrated in the last decade.
Recently, it has been accepted as a root canal irrigant in
endodontics.
Advantages:
•Has a broad spectrum antimicrobial action.
•Relative absence of toxicity.
Disadvantage – it is not known to possess a tissue dissolving
property.
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Structure is a symmetrical cationic molecule consisting of:
4-chlorophenyl rings and 2 biguanide groups
Connected by a central hexamethylene chain
Specturm of activity
Chlorhexidine is bactericidal and effective against gram
+ve, gram-ve, yeast, Candida albicans.
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Action:
Acts by adsorbing into the cell wall of the
microorganisms and causing leakage of the intracellular
components.
At low concentration has bacteriostatic effect.
At higher concentration, chlorhexidine is bactericidal
because of precipitation or coagulation of the cytoplasm
caused by protein cross linking.
The bacteriostatic effect of chlorhexidine is
considered to be more effective. The bound chlorhexidine
molecule is slowly released for upto 24 hours, as the
concentration decrease.
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According to Klimn et al
When used as an intra canal irrigant in the endodontic
treatment for periapical lesions:
•Clinical relief of symptoms.
•Sterility.
•Reduction in the size of periapical lesions.
All at a mean follow up of 24 months.
In another study (O hara et al) showed that chlorhexidine was
the most efficient antibacterial agent when compared to 3%
H2O2, 5.25% NaOCl, saline REDTA 17%.
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Iodides :
Iodine has been used for many years and is known for its
mild effect on living tissue.
Iodine is highly reactive, combining with proteins in a
loosely bound manner so its penetration is not impeded.
Iodine potassium iodide which contains 2% I2, 4% KI and
94% distilled water has excellent antimicrobial activity and minimal
toxicity and tissue irritating qualities.
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Cationic detergents
The quaternary ammonium compounds have low surface
tension and good cleansing effect.
The antimicrobial effect of these compounds are not strong.
Mechanism of action is as follows, the ‘Quats’ are
positevely charged and the microorganisms are negatively
charged. Thus a surface active effect results in which the
compound clings to the microorganism and reverses the charge.
These compounds may delay wound healing
These compounds are used in the concentrations between
0.1 to 1% for root canal irrigation, but rarely as intracanal
dressings
Salvizol is also a detergent suggested for irrigation during
root canal instrumentation
It has chelating effect
Salvizol causes some degree of tissue irritation
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9-AMINOACRIDINE
The efficacy of 9-aminoacridine has been reviewed by
Schmitz.
Properties:
1.Antibacterial action.
2.Low toxicity.
3.Osteogenic potential.
Disadvantage:
• Not a chelator.
• Not a tissue solvent.
It use is not widespread.
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Mechanism of action:
Disruption of cellular metabolic pathways of microorganisms:
-Inhibition of cells, protein synthesis.
-Inhibition of DNA synthesis.
Use:
a) Management of endodontically involved teeth with large
periapical abscess.
b) Recommended as pressure irrigation of the periapical tissues
via the canals.
c) The drug may be sealed in the canal as an interim medication
( low inflammatory potential)
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Glyoxide
Glyoxide is an irrigation solution i.e. comprised of 10% urea
peroxide (Carbamide peroxide) in a vehicle of anhydrous
glycerol.
Use:
•Narrow and curved canals where slippery effect of glycerol is
maximized for instrumentation.
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Action:
a) Antibacterial activity that is more potent than 3% H2O2.
b) Enhances root canal lubrication without softening the
dentin.
(less chance of root perforation)
a) It is less toxic to periapical tissues than NaOCl.
b) It also has greater solvent action than 3% H2O2.
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DOXYCYCLINE HYDROCHLORIDE
A hydroxy derivative of tetracycline.
It is the most potent anticollagenase antibiotic among
commercially available tetracyclines.
Advantages:
a) The dentin surface is capable of acting as a reservoir by
adsorbing and slowly releasing antibacterial levels of
doxycycline into the adjacent environment for several days
following topical applications of this antibiotic solutions.
b) Inhibit extracellular collagenase activity and bone
resorption.
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Metronidazole
Antibiotic spectrum confined solely to obligate anaerobes.
Active against bacteroides, porphyromonas fusibacterium,
clostridium and peptococci and peptostreptococci.
Barnett and Tronstad in 2002 reported the successful use of
metranidazole in controlling infections by bacterioides spp and
pseudomonas spp colonized at root ends of endodontically
treated teeth that had failed to heal and remained refractory to
all other treatment.
66
Adverse reactions:
1.Nausea.
2.Headache.
3.Metallic taste.
4.Xerostomia.
67
Calcium hydroxide
Hermann introduced Ca(OH)2 paste as an intra canal medicament in
1920.
Thick suspension of Ca(OH)2 powder in sterile water or saline.
The high pH of calcium hydroxide paste is responsible for the destructive
effect on bacterial cell membranes and protein structures.
Aid directly or indirectly in the dissolution of necrotic pulp tissue. Tissue
submerged in Ca(OH)2 for a day is more easily dissolved with NaOCl than
is untreated tissue.
Bystrom et al showed that Ca(OH)2 paste effectively eliminated all
microorganisms in infected root canals when the dressing was maintained
for 4 weeks.
68
Mode of application :
 The paste is introduced into the root canal with a lentulo
spiral, dried with coarse absorbent points and packed with
appropriately sized root canal pluggers.
Temporary cement is then placed for an effective seal.
69
Antibiotics
Antibiotics are indicated in a small minority of cases when
root canal infection persists despite other antiseptics.
Ladermix paste or polyantibiotic paste (PBSC) are used
70
Ledermix paste
1% triamcinelone acetonide (Glucocorticosteroid)
3% dimethl chlortetracycline
PBSC paste
Potassium penicillin G (10,00,000 units)
Bacitracin (10,000 units)
Streptomycin paste (1gm)
Sodium caprylate / Nystatin (1gm)
71
Conclusion
Debridement of the root canal systems is essential for a
predictably successful endodontic treatment.
The identification and elimination of bacteria, removed of
other necrotic products from the canal with appropriate
irrigating solutions with proper technique ensures definite
fulfillment of one of the objectives of root canal therapy.