Endodontic Irrigants

 •Irrigation has been performed in conjunction with endodontic therapy for many years. One of the primary reasons for irrigating the root canal system is to ensure cleaning of the canals prior to obturation. This cleanling involves both:•elimination of microorganisms and removal of organic matter

Desiared functions of irrigating solutions

 •_ Washing action (helps remove debris)•_ Reduce instrument friction during preparation (lubricant)•_ Facilitate dentin removal (lubricant)•_ Dissolve inorganic tissue (dentin)•_ Penetrate to canal periphery•_ Dissolve organic matter (dentin collagen, pulp tissue, biofilm)•_ Kill bacteria and yeasts (also in biofilm)•_ Do not irritate or damage vital periapical tissue, no caustic or cytotoxic effeActs• Do not weaken tooth structure 

Benefits of irrigation during endodontic work

Making a wet environment during preparation ..the dentin shaving floating to the chamber

Files and reamers are less likely to break when the canal is wet

The irrigant that are typically used have the function of necrotic tissue solvent

The irrigants loosen depris, pulp tissue , and M,O from

irregular dentin walls Most irrigants are germicidal •Also have ableaching action to lightens teeth discolored by trauma post operative darkness

Useful irrigants

Sodium hypochlorite(naocl) Most widely used. the pH of sodium hypochlorite is near 12. During the treatment of a root canal, the increase in pH likely creates a microenvironment that is not particularly hospitable to bacteria in the root canal system. . It is potently antimicrobial and dissolves organic

material. It also affects -- but doesn't remove -- the smear layer.

Removal of the smear layer enhances obturation and decreases apical leakage.

NaOCl may also cause pain and injure periapical tissues when it extrudes through the apex. 

EDTA and CA

•Complete cleaning of the root-canal system requires the use of irrigants that dissolve organic and inorganic material. As hypochlorite is active only against the former, other substances must be used to complete the removal of the smear layer and dentin debris.• EDTA and CA effectively dissolve inorganic material, including hydroxyapatite.. EDTA is most commonly used as a 17% neutralized solution (disodium EDTA, pH 7), but a few reports have indicated that solutions with lower concentrations (eg, 10%, 5%, and even 1%) remove the smear layer equally well after NaOCl irrigation

Cross section of root dentin covered by the smear layer created by instrumentation.

Notice smear plugs in dentin canals 

Chlorhexidine Digluconate• Chlorhexidine digluconate (CHX) is widely used in disinfection in dentistry because of its good antimicrobial activity. It has aconsiderable popularity in endodontics as an irrigating solution and as an intracanal medicament. CHX does not possess some of the undesired characteristics of sodium hypochlorite (ie, bad smell and strong irritation to periapical tissues). However, CHX has no tissue-dissolving capability and therefore it cannot replace sodium hypochlorite

• . One of the reasons for the popularity of CHX is its substantivity (ie, continued antimicrobial effect), because CHX binds to hard tissue and remains antimicrobial.

Other Irrigating Solutions

•Other irrigating solutions used in endodontics have included• sterile water,• physiologic saline,• hydrogen peroxide, •urea peroxide, •and iodine compounds.• All of these except iodine compounds lack antibacterial activity when used alone, and they do not dissolve tissue either. Therefore there is no good reason for their use in canal irrigation in routine cases. In addition, water and saline solutions bear the risk of contamination if used from containers that have been opened more than once.• Iodine potassium iodide (eg, 2% and 4%, respectively) has considerable antimicrobial activity but no tissue dissolving capability and it could be used at the end of the chemomechanical preparation like CHX.

Interactions Between Irrigating Solutions

•Hypochlorite and EDTA are the 2 most commonly used irrigating solutions. As they have different characteristics and tasks, it has been tempting to use them as a mixture.•However, EDTA (and CA) instantaneously reduces the amount of chlorine when mixed with sodium hypochlorite, resulting in the loss of NaOCl activity. Thus, these solutions should not be mixed.

CHX & Naocl

•CHX has no tissue-dissolving activity and there have been efforts to combine CHX with hypochlorite for added benefits from the 2 solutions. However, CHX and NaOCl are not soluble in each other; a brownish-orange precipitate is formed when they are mixed .

CHX and EDTA

•Mixing CHX and EDTA immediately produces a white precipitate * it seems that the ability of EDTA to remove the smear layer is reduced.

IRRIGATION DEVICES AND TECHNIQUESConventional

• Syringes• Needles

EndoActivator

• It is based on sonic vibration (up to 10,000 cpm) of a plastic tip in the root canal

Endo

Vac

• , the EndoVac system is based on a negative-pressure approach whereby the irrigant placed in the pulp chamber is sucked down the root canal and back up again through a thin needle with a special design

SyringesPlastic syringes of different sizes (1–20 mL) are most commonly used for irrigation.Although large-volume syringes potentially allow some time-savings, they are more difficult to control for pressure and accidents may happen. Therefore, to maximize safety and control, use of 1- to 5-mL syringes is recommended instead of the larger ones.

• **Because of the chemical reactions between many irrigants, separate syringes should be used for each solution

Needles• Although 25-gauge needles were commonplace for

endodontic irrigation, they were first replaced by 27-G needles, now 30-G and even 31-G needles are taking over for routine use in irrigation.

Flexi-Glide Utility Tips•Vista Dental's Flexi-Glide Utility Tips are disposable tips that are ideal for irrigation, application, and micro-aspiration. Constructed of polyimide tubing, Flexi-Glide's flexible, crimp-resistant tip facilitates access and provides maximum reach during canal procedures.•

EndoActivator

• is a new type of irrigation facilitator. It is based on sonic vibration (up to 10,000 cpm) of a plastic tip in the root canal.

• The system has 3 different sizes of tips that are easily attached (snap-on) to the handpiece that creates the sonic vibrations

the use of EndoActivatorfacilitates irrigant penetration and mechanical cleansing compared with needle irrigation, with no increase in the risk of irrigant extrusion through the apex.•

MULTIPLE BENEFITS

SAFE Strong, flexible medical grade polymer tips

Single patient use

Uncoated & non cutting tips

• EFFECTIVE Create fluid hydrodynamics

Improves debridement and the disruption of the smear layer and biofilm

• SIMPLE Very simple clinical technique

Intuitive device

Ideal in practice when portability is required

EndoVacthe EndoVac system is based on a negative-pressure approach whereby the irrigant placed in the pulp chamber is sucked down the root canal and back up again through a thin needle with a special design

advantages•1-the EndoVac system lowers the risks associated with irrigation close to the apical foramen considerably. • 2-Another advantage of the reversed flow of irrigants may

be good apical cleaning at the 1-mm level and a strong antibacterial effect when hypochlorite is used

THANK YOU