Most important intra canal medicaments frequently asked (Normal saline, Essentia Oil ,Phenol, Aldehydes, Calcium hydroxide, PBSC, Halogen, Chlorhexidine)

1. Normal Saline

From a biological standpoint, sterile normal saline is the best irrigant to use because it causes.

Least apical tissue irritation or damage.
Biocompatible.
Least amount of cell lysis.

Disadvantages

Does not remove the smear layer.
Flushes out some of the superficial debris from the root canal system.
Has poor antibacterial properties.

2. Essential Oils

Eugenol

It has been used for many years.
It is a constituent of most root canal sealers and is used as a part of many temporary sealing agents.
This substance is the chemical essence of oil of clove and is related to phenol.

2 Types

Low Dose (Beneficial Effects)

Inhibits Prostaglandins Synthesis.
Inhibits Nerve Activity.
Inhibits White Cell Chemotaxis

High Dose (Toxic Effects)

Induces Cell Death.
Inhibits Cell Respiration

Uses of eugenol

Used as an intracanal medicament.
Used as root canal sealers.
Part of temporary sealing agents.

3. 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.

Uses of phenol

It is used for disinfection before periapical surgery.
It is also used for cauterizing tissue tags that resist removal with broaches or files.

TYPES

a. 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
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.

b. 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

c. Cresatin

Schilder and Amsterdam showed that Cresatin possesses same desirable qualities and actions as that of CMCP, but less irritating to periapical tissues.

Composition: It is a clear, stable, oily liquid of low volatile nature known as metacresyl acetate.

4. Aldehydes

Formocresol

Developed by BUCKLEY in 1906
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 is good at levels as low as 2%.
It is a strong poison and causes widespread destruction of living tissue followed by a persistent inflammatory reaction.

Contents : 19% formaldehyde,
- 35% cresol
- 46% water Glycerine

5. Calcium Hydroxide

Use of calcium hydroxide in endodontics was introduced by Hermann in 1920. It acts as a strong base in contact with aqueous solution and dissociate into calcium and hydroxyl ions.

Effect of Calcium Hydroxide

CHEMICAL

Shows antiseptic action
Suppresses enzymatic activity and disrupts cell membrane
Inhibits DNA replication by splitting it
It hydrolyses the lipid part of bacterial lipopolysaccharide

PHYSICAL

Acts as a physical barrier for ingress of bacteria.
Destroys the remaining bacteria

a. Form and application:

Can be placed as a dry powder, a powder mixed with a liquid such as local anaesthetic solution, saline, water or glycerine to form a thick paste, or a paste supplied in a syringe.

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 LENTULO SPIRAL

b. Advantages

Inhibits root resorption.
Stimulates periapical healing.
Encourage mineralization.

c. Disadvantages of Ca(OH)2 as intracanal medicament.

Difficult to remove from canals.
Decreases setting time of zinc oxide eugenol-based cements.
It has a little or no effect on severity of post obturation

WHAT IS A WEEPING CANAL?

A tooth undergoing root canal treatment shows constant clear or reddish exudation associated with periapical radiolucency. Tooth can be asymptomatic or tender on percussion. When opened in next appointment, exudates stops but it again reappears in next appointment. This is known as “weeping canal”.

NOTE:

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.

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

6. Halogens

Halogens include chlorine and iodine. They are potent oxidizing agents with rapid bactericidal effects.

Chlorine

Disinfectant action of halogens is inversely proportional to their atomic weights.
When compared to iodine, chlorine shows better disinfectant action.
But chlorine disinfectants are not stable compounds as they interact rapidly with organic matter

Iodides

Iodine is highly reactive in nature.
It combines with proteins in a loosely bound manner.
It destroys microorganisms by forming salts that are unfavorable to the life of the organism.

7. Chlorhexidine (CHX)

Chlorhexidine (CHX) has been recently used as an intra-canal medicament.
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

8. PBSC Paste

PBSC paste

By Grossman
Penicillin—against Gram-positive microorganisms
Bacitracin—against penicillin-resistant microorganisms
Streptomycin—against the Gram-negative microorganism
Caprylate (sodium salt)—against fungi

PBSN

Nystatin—replaces sodium caprylate as antifungal agent
PBSC interferes culturing procedures—penicillinase is added to culture media to inactivate penicillin.