Irrigation and IntracanalMedicaments

Ideal Requirements for an Irrigant• 1. Broad spectrum antimicrobial properties.

• 2. Aid in debridement of the root canal system.

• 3. Ability to dissolve necrotic tissue or debris.

• 4. Low toxicity level.

• 5. Good lubricant.

• 6. Low surface tension to flow into inaccessible area.

• 7. Ability to sterilize the canal.

• 8. Prevent/dissolve smear layer.

• 9. Inactivate endotoxin.

Functions of irrigants• 1. Remove dentinal shavings by physical flushing.

• 2. Increase the efficiency of instruments.

• 3. Dissolve necrotic tissue.

• 4. Remove debris from lateral and accessory canals.

• 5. Germicidal as well as antibacterial properties.

• 6. Bleaching action.

• 7. Irrigants with lubricating agent further increase the efficiency.

• 8. Opening of dentinal tubules by removal of smear layer.

Factors modifying the activity of irrigating solutions

• 1. Concentration: Tissue dissolving capability of NaOCl is higherat 5.2 percent.

• 2. Contact: To effective, irrigant must come in contact with thesubstrate.

• 3. Presence of organic tissue: Organic tissues must be removedfor effective irrigation.

• 4. Quantity of the irrigant used: Increase in quantity increases theeffectiveness.

• 5. Gauze of irrigating needle: 27 or 28 gauze is preferred for betterpenetration in the canal.

• 6. Surface tension of irrigant: Lower the surface tension, betteris wettability.

• 7. Temperature of irrigant: Warming the NaOCl increases itsefficacy.

• 8. Frequency of irrigation: More is frequency, better are the results.

• 9. Level of observation.

• 10. Canal diameter: Wider the canal, better is action of irrigant

• 11. Age of irrigant: Freshly prepared solutions are more efficient then older ones.

Commonly used irrigating solutions• Chemically non-active solution

• Water

• Saline

• Local anesthetic

• Chemically active materials:

• Alkalis: Sodium hypochlorite 0.5-5.25 percent

• Chelating agents: Ethylene diamine tetra acetic acid (EDTA)

• Oxidizing agents: Hydrogen peroxide, carbamide peroxide

• Antibacterial agents: Chlorhexidine, Bisdequalinium acetate

• Acids: 30 percent hydrochloric acid

• Enzymes: Streptokinase, papain, trypsin

• Detergents: Sodium lauryl sulfate

Sodium Hypochlorite

• Mechanism of Action

• reactive chlorine in aqueous solution exists in two forms-hypochlorite (OCl–) and hypochlorous acid (HOCl).

• State of available chlorine depends on pH of solution, i.e. above pH of 7.6, it is mainly hypochlorite form and below this pH, it is hypochlorous acid.

• Presence of 5 percent of free chlorine in sodium hypochlorite is responsible for breakdown of proteins into amino groups

• The pH of commonly used sodium hypochlorite is 12, atwhich the OCl form exits. Hypochlorite dissolves necrotictissue because of its high alkaline nature (pH 12)

Advantages of Sodium Hypochlorite

1. It causes tissue dissolution.

2. It has antibacterial and bleaching action.

3. It causes lubrication of canals.

4. Economical.

5. Easily available

Disadvantages1. Because of high surface tension, its ability to wet dentin is less.

2. Irritant to tissues, if extruded periapically, it can result in severe cellular damage.

3. If comes in contact, it cause inflammation of gingiva because of its caustic nature.

4. It can bleach the clothes if spilt.

5. It has bad odor and taste.

6. Vapors of sodium hypochlorite can irritate the eyes.

7. It can be corrosive to instruments.

HYDROGEN PEROXIDE

• 3 percent solution

• It rapidly dissociates into H2O + [O] (water and nascent oxygent).

• 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 oforganic debris.

CHLORHEXIDINE

• optimal antimicrobial action between pH 5.5-7.0

• 2% in concentration

• At low concentration, it acts as a bacteriostatic, whereas at higher concentrations; it causes coagulation and precipitation of cytoplasmand therefore acts as bactericidal.

Advantages and Uses

1. A 2 percent solution is used as root irrigant in canals.

2. A 0.2 percent solution can be used in controlling plaque activity.

3. It is more effective on gram-positive bacteria than gram negative bacteria.

Disadvantages

• 1. It is not considered as the main irrigant in standard endodontic therapy.

• 2. It is unable to dissolve necrotic tissue remnants.

• 3. It is less effective on gram-negative than on gram-positive bacteria.

CHELATING AGENTS

• EDTA and other chelating agents like citric acid, polyacrylic acids are used for this purpose

Functions of EDTA

• Lubrication• Emulsification• Holding debris in suspension• Smear layer removal

Uses of EDTA

• It has dentin dissolving properties

• It helps in enlarging narrow canals

• Makes easier manipulation of instruments

• Reduces time needed for debridement

INTRACANAL MEDICAMENTS

• Destroy the remaining bacteria and also limits the growth of new arrivals.

• Useful in treatment of apical periodontitis for example in cases of inflammation caused due to over instrumentation

Eugenol

Uses of Eugenol

1. Used as an intracanal medicament.

2. Used as a root canal sealers.

3. Part of temporary sealing agents.

Phenol

• it has strong inflammatory potential, so, at present,it is rarely used as an intracanal medicament.

• Liquefied phenol (Carbolic acid) consists of 9 parts ofphenol and 1 part of water.

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

Camphorated Monoparachlorophenol(CMCP)

• It is probably the most commonly used medicament inendodontics presently, even though its use has decreased considerably in the past few years

• Composition2 parts of para-chlorophenol

+3 parts gum camphor

↓Camphorated monochlorophenol (CMCP)

• UsesUsed as a dressing of choice for infected teeth.

Formocresol

• Formocresol contains formaldehyde as its main ingredient and is still widely used medicament for pulpotomy procedures in primary teeth.

• its toxic and mutagenic properties are of concern

• UsesUsed as dressing for pulpotomy to fix the retained pulpal tissue

• Composition of formocresolFormaldehyde — 19 percentCresol — 35 percentWater and glycerine — 46 percent

Calcium Hydroxide• Indications of Calcium Hydroxide

• In weeping canals• In treatment of phoenix abscess• In resorption cases• For apexification• During pulpotomy• For non surgical treatment of periapical lesion• In cases of direct and indirect pulp capping• As sealer for obturation• To decrease postoperative pain after over instrumentation

• Functions of Ca(OH)21. Inhibits root resorption2. Stimulates periapical healing3. Encourage mineralization