Intracanal medicaments

By

Ahmed Mostafa Hussein

Assistant lecturer, Dental Biomaterials Department Faculty of Dentistry, Mansoura University

20141

Functions

1. Destroy the microorganisms and prevent regrowth.

2. Reduce inter-appointment pain. It is useful in treating

apical periodontitis as a result of overinstrumentation.

3. Useful in weeping canals (constant clear or reddish

exudate, large apical radiolucency, and if cultured, the

drainage will not support bacterial growth)

4. May inhibit root resorption in case of replanted teeth.

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Ideal requirements:

1. Effective germicide and fungicide.2. Non irritating to periapical (PA) tissues.3. Stable in solution.4. Have antibacterial effect for prolonged period.5. Active in presence of blood and serum.6. Low surface tension.7. Should not interfere with repair of PA tissues.8. Should not stain the tooth.

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1.Phenols

Phenols are ineffective antiseptics under clinical

conditions , it is rarely used as an intra-canal

medicament as it has strong inflammatory

potentials.

Eugenol has a high irritating potential when

evaluated histologically but it seems to be

extremely soothing clinically to vital tissue.

camphorated mono-para-chloro-phenol (CMCP)

has decreased tremendously.

CMCP placed in the pulp chambers loses nearly

90% of their activity within the first 24 hours.

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2. ALDEHYDES

Formo-cresol

It is a combination of formalin and cresol.

it is potent toxin with an antimicrobial effectiveness much lower than

their toxicity.

Formo-cresol is used as a dressing for pulpotomy to fix the retained

pulpal tissue.

It may be used as an intra-canal medicament when a pulpotomy is

performed as emergency treatment to relieve pain.

No clinical reason to use formo-cresol as an

antimicrobial agent for endodontic treatment.

The alternatives are better antiseptics with

significantly lower toxicity.

It is placed on a cotton pellet in the pulp chamber and the

vapor penetrate the entire canal preparation.

3. Calcium hydroxide Ca(OH)2

Ca(OH)2 is effective in inhibiting microbial growth in

canals, although it remains controversial.

(see limitations of Ca(OH)2)

No pain reduction effects.

Recommended for use in teeth with necrotic pulp

tissue and bacterial contamination.

Has little benefit with vital pulps.

Form and application:

Can be placed as a dry powder, a powder mixed with

a liquid such as local anesthetic solution, saline, water

or glycerine to form a thick paste or a paste supplied

in a syringe.

A lentulo spiral is effective and efficient for placement.

Removal after placement is difficult. This is especially

true in the apical portion of the root.

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Lentulo spiral

Note: Long term use of Ca(OH)2 may be necessary.

However, the use of intracanal medicament for long

periods does not seem to be acceptable in modern

endodontics.

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Ca(OH)2 is useful for weeping cases

Weeping cases: the tooth with

1. Constant clear or reddish exudation

2. A large apical radiolucency

3. Often asymptomatic, but it may be tender to

percussion or sensitive to digital pressure over the apex.

4. If cultured, the drainage generally will not support

bacterial growth.

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5. When opened at the start of endodontic

appointment, there is a reddish discharge. At the

succeeding appointment, the exudate will be clear. It

is referred as a weeping canal.

Canals with exudates were not considered to be

ready for filling.

Prescribing antibiotics for the patient seems foolish,

because of the frequency of negative cultures.

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Treatment: the treatment of this problem is to dry

the canal with sterile absorbent paper points and

place Ca(OH)2 paste in the canal.

It is interesting to see a perfectly dry clean canal at

the next appointment that is simple to fill after

minimal further preparation.

Limitations of Ca(OH)2

Residual Ca(OH)2 can shorten the setting time of

zinc oxide eugenol-based endodontic sealers.

Ca(OH)2 is not totally effective against E. faecalis

and candida albicans.

Dentin can inactivate the antibacterial activity of

Ca(OH)2.

A clinical study has shown that the number of bacteria-

positive canals actually increased after Ca(OH)2

medication.

Other studies have also indicated that cultures changed

from negative to positive after Ca(OH)2 placement.

Therefore, based on the current best available evidence,

Ca(OH)2 has limited effectiveness in eliminating

bacteria from human root canals.

4. Chlorhexidine (CHX)

Chlorhexidine (CHX) has been recently used as an

intra-canal medicament.

A 2% gel is recommended.

It can be used alone in gel form or mixed with

Ca(OH)2.

When used with Ca(OH)2, the antimicrobial

activity is greater than when Ca(OH)2 is mixed

with saline, although it remains controversial.

2% CHX gel was significantly more effective than

Ca(OH)2 combined with 2% CHX or Ca(OH)2

alone, against root dentin infected with E. faecalis

and candida albicans after 7, 15 and 30 days of

incubation.

5. Iodine potassium iodide (IKI)

Iodine potassium iodide (IKI) is very effective

antiseptic solution with low tissue toxicity.

IKI releases vapours with a strong antimicrobial

effect.

IKI can kill bacteria in infected dentin in 5 minutes

in vitro.

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6 .ANTIBIOTICS

Sulphonamides are used as medicaments by mixing distalled water or moistened paper point into jar containing the powder.

It is indicated in case of acute peri-apical abcess.

Disadvatage, yellowish tooth discoloration.

7. Corticosteroid-antibiotic combination

Corticosteroids are anti-inflammatory agents that may

decrease postoperative pain in certain situations e.g.

irreversible pulpitis and acute apical periodontitis.

Corticosteroids may be ineffective, particularly with greater

pain levels.

Corticosteroid-antibiotic combinations are useful in treating

apical periodontitis, occurring either as a pretreatment

symptom or as a result of overi-nstrumentation.

Ledermix is a corticosteroid-antibiotic paste, made

in Germany.

Ledermix is a nonsetting, water-soluble paste, used

as root canal medicament or as direct or indirect

pulp capping agent.

At the first 24 hours, 30% of the corticosteroid was

released. By the end of 14 weeks, the remaining

70% has been released.

In case of replanted teeth, immediate intracanal

placement of Ledermix may inhibit root

resorption.

Note: Intracanal antibiotic paste may cause

bacterial resistance.

Mixing erythromycin with Ca(OH)2 improved the

effectiveness against E. faecalis as compared to

Ca(OH)2 alone.

In general, specific information about the

effectiveness of intra-canal antibiotics in infection

control in endodontics is limited.

Questions What are the indications of

Formocresol

Ca(OH)2

Corticosteroid-antibiotic combination

?

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