root canal irrigants

Ass.Prof.Dr.Mohamed ALsakkafAss.Prof.Dr.Mohamed ALsakkaf 11

Root Canal Irrigants

.Irrigants perform important physical and biological roles during endodontic therapy. When there is wet environment during canal preparation the dentin debrises are floated to the chamber. Where they be remove by paper points or others.

.Many liquids would provide these aids, but in addition the irrigants that are typically used have the function of being necrotic

tissue solvents .

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.Because reamers and files much too small to fit into accessory canals, it is the solvents action that removes the tissue remaining and also the subsequently filling material may be packed or pushed into these areas.

.The commonly used irrigants are capable of causing inflammation of periapical tissue. Therefore instrumentation must be confined within the canal to limit the forcing of irrigants through the apical

foramen .

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Requirements of Ideal Irrigants

1 .It must have broadspectrum antimicrobial effect.

2 .It must aid in the root canal debridement.

3 .Ability to dissolve necrotic tissue or debris.

4 .Low toxicity level.

5 .Act as a good lubricant.

6 .Low surface tension to flow easily into the inaccessible areas.

7 .Remove the smear layer.

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Factors Effecting The Irrigants action

1 .Concentration.

2 .Contact.

3 .Presence of organic tissue.

4 .Quantity.

5 .Temperature.

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Remember:

The smear layer is a micro – crystalline layer of cutting debris covering the canal walls after the preparation and its removal may aid in better adaptation of the obturating materials to the canal walls.

It consist of:

A. Organic layer ----- removed by irrigants.

B. Inorganic layer --- removed by chealating agent.

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Types of Irrigants

1 .Sodium hypochloride (NaOCL)(PH 12 – 13).

.The most popular irrigant.

.It provides:

a. Gross debridement.

b. Dissolution of tissue.

c. Lubricant.

d. Antibacterial.

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.Warming NaOCL increases its tissue solvent effect .

.It is provided in bottles of 5.2%.

.It, is clear, pale, green – yellow liquid, with strong odor of chlorine.

.Solution should always be performed passively especially in cases with larger apical diameters, and needles with very small diameter, also the syringes should never be locked in the canal.

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2 .Hydrogen Peroxide (H2O2) 3%

.It is odorless, clear liquid.

.Its effervescence action capable for removing loose debris from inside the canal.

.Release of nascent oxygen (O3) works against anaerobic bacteria.

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.Combining 5.25% NaOCL + 3% H2O2 proved to be better than saline alone at 1 – 3mm level of the canal.

.If Hydrogen Peroxide is used, final irrigant should be NaOCL because, it may cause either:

1 .Tissue emphysema if it passes to the periapical tissue.

2 .Post – Operative Pain.

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3 .Chlorhexidine Gluconate (0.2% - 2%)

.It has antibacterial effect (long standing effect by binding to hydroxyapatite and in combination with Ca(OH)2 effective against anaerobes).

.Does not have tissue solvent action.

.Low toxicity compared to NaOCL.

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4 .Organic acid as citric acid 10 – 25% in combination with NaOCL removes smear layer.

5 .MTAD

M ----- Mixture of

T ----- Tetracycline

A ----- Acid (citric acid)

D ----- Detergent

Recommendation: 1.3 – 2.5% NaOCL is the irrigant of choice during the preparation.

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Method of Irrigation

.Plastic syringe of acceptable needle gauge.

30 = 30 File Iso.

27 = 40 File Iso.

25 = 50 File Iso.

23 = 60 File Iso.

21 = 80 File Iso.

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.Bending the needle and it must lie passively in the canal as forceful irrigation can push the irrigant into the periapical tissue.

.Volume of irrigation about 2ml each time.

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The Ultrasonic Irrigation: Considered the most effective method of irrigation where vibration motion of files inside the canal:

1 .Move irrigant in Vortex motion cleaning the area which cannot be reached by files.

2 .The motion causes worming of the irrigant, increasing its action.

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Combination of Irrigants

1 .H2O2 NaOCL ---- Foaming action.

2 .EDTA + NaOCL ---- Removes Smear Layer.

3 .EDTA + Urea Peroxide + NaOCL increase bubbling action, debridement and removal of smear layer.

4 .MTAD + NaOCL: For disinfection and smear layer removal.

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Chealating Agents

.Chelate: react with calcium, so their action is to react with calcium ions and substitute it by sodium ions which can bind to dentin to give soluble salt.

.It used to enlarge narrow curved and calcified canals.

.Aids in the removal of Smear Layer (inorganic part).

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Types of Chealating Agents

a. Ethylene Diamine Tetra Acetic Acid (EDTA) are the active ingredients in all types.

.It used for cleaning and widening the canal.

.Used in concentration of 17%.

.Optimal working time 15 minutes.

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b. EDTA C:

EDTA Cetavlon which increases anti – bacterial activity.

.Combination of EDTA + Urea peroxide, provides both chelation and irrigation.

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Intra Canal Medicaments

.They are medicaments used in root canal between appointments.

I. The popular intra canal medicaments were designed and proposed for the following:

1 .Anti – microbial activity in the pulp and periapex.

2 .Neutralization of canal remnant to render them inert.

3 .Control or prevention of post – treatment pain.

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II. The use of traditional medicaments is decreased, because:

a. Intra canal bacterial population can be eliminated by careful instrumentation and irrigation.

b. Lack of evidence of medicament usefulness.

c. Toxicity.

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III. Limitation and Contraindications.

1 .Intracanal environment:

.The therapeutic action of the medicaments depends on the direct contact with the microbe or tissue.

.Their effect is probably limited to surface action only and does not reach the area, where the bacteria are hidden.

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2 .Duration:

.Most agents should remain chemically active for the period of time between appointments, in order to be effective.

.Phenolics loose their activity within 24 hrs.

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3. Toxicity:

a. Any chemical that kills bacteria, will also kill host cells (Phenol, aldehyde).

b. An adverse side effect is also: Allergenicity. As the medicaments may act as a hapten and alter the tissue to become foreign substances, producing an immune response. May be responsible for their localized adverse effect on the pulp and / or periapical tissue.

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4. Distribution:

.The pulp is not isolated from the rest of the body, as the pulp has a ready accessibility to the periapical tissue and even to the systemic circulation.

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5 .Taste and Smell:

Phenolics in particular have a pungent odour and foul taste. The patient will report a disagreeable medicinal taste, which many find objectionable.

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Recently Used Intra Canal Medicaments

1 .Calcium hydroxide:

a. The most popular intra canal medicament .

b. It gas antimicrobial action (due to its alkaline PH) .

c. Increase organic tissue solvent of NaOCL.

d. Alkaline neutralizes the acidity of inflammation.

Application of Calcium Application of Calcium HydroxideHydroxide

Antimicrobial Action Antimicrobial Action ((germs coming in contact germs coming in contact with the paste are easily destroyed by the high with the paste are easily destroyed by the high

pHpH))

Bone-regenerating effectsBone-regenerating effects (stimulates the (stimulates the osteoblastic activity and osteoblastic activity and hard tissue deposition hard tissue deposition ). ).

Used in case of root resorption and inmature teethUsed in case of root resorption and inmature teeth..

Aid the dissolution of organic material Aid the dissolution of organic material remaining in the root canal after preparationremaining in the root canal after preparation..

Very good biocompatibilityVery good biocompatibility..

2929Thin aqueous suspension of Ca(OH)2 used as dressing

Placement of Medicaments

Syringe Delivery

Spiral Fillers

Hand File

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Available as:

1 .Powder.

2 .Paste.

3 .Active Point.

4 .Injectable.

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2 .Antibiotics:

It was tried as intra canal medication, but fear of developing bacterial resistance which leads, to decrease its use.

3 .Steroids:

It was tried due to its anti inflammatory effect, to avoid post operative pain.

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4. Combination (steroids and antibiotics).

a. Steroids ------ An inflammatory effect.

b. Antibiotics ------ Controlling infection.

Used mainly in case of acute pulpitis with apical periodontitis.

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Iodine Potassium IodideIs it an iodoform/calcium hydroxide paste that has been shown to reduce the presence of all bacteria but especially Enterococcus Faecalisi, a hardy bacterium commonly

associated with failing root treatments.

.May be useful as an irrigant and intracanal dressing in retreatment cases .