• Irrigation has been performed in conjunction with endodontictherapy for many years. One of the primary reasons for irrigatingthe root canal system is to ensure cleaning of the canals priorto obturation. This cleanling involves both:• elimination of microorganisms and removal of organicmatter
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 orcytotoxic 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 traumapost operative darkness
Useful irrigantsSodium 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 createsa microenvironment that is notparticularly hospitable to bacteria in the root canal system. . It is potently antimicrobial and dissolves organic material. It also affects -- but doesnt 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 theformer, other substances must be used tocomplete the removal of the smear layerand dentin debris.• EDTA and CA effectively dissolveinorganic material, including hydroxyapatite.. EDTA is most commonly used asa 17% neutralized solution (disodium EDTA, pH 7), but a fewreports have indicated that solutions with lower concentrations (eg,10%, 5%, and even 1%) remove the smear layer equally well afterNaOCl 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 activitywhen used alone, and they do not dissolve tissue either. Therefore thereis no good reason for their use in canal irrigation in routine cases. Inaddition, water and saline solutions bear the risk of contamination ifused from containers that have been opened more than once.• Iodine potassium iodide (eg, 2% and 4%, respectively) hasconsiderable antimicrobial activity but no tissue dissolving capability andit could be used at the end of the chemomechanical preparation likeCHX.
Interactions Between Irrigating Solutions• Hypochlorite and EDTA are the 2 most commonlyused irrigating solutions. As they have differentcharacteristics and tasks, it has been tempting to usethem as a mixture.• However, EDTA (and CA) instantaneously reduces theamount of chlorine when mixed with sodiumhypochlorite, resulting in the loss of NaOCl activity.Thus, these solutions should not be mixed.
CHX & Naocl• CHX has no tissue-dissolving activity and there havebeen efforts to combine CHX with hypochlorite for addedbenefits from the 2 solutions. However, CHX and NaOClare not soluble in each other; a brownish-orange precipitateis formed when they are mixed .
CHX and EDTA• Mixing CHX and EDTA immediately produces a whiteprecipitate * it seems that the ability of EDTA toremove the smear layer is reduced.
IRRIGATION DEVICES AND TECHNIQUES • Syringes Conventional • Needles • It is based on sonic vibration (up to 10,000EndoActivator cpm) of a plastic tip in the root canal • , the EndoVac system is based on a negative- pressure approach whereby the irrigant placed in the pulp chamber is sucked down the root canal andEndoVac back up again through a thin needle with a special design
SyringesPlastic syringes of different sizes (1–20 mL) are most commonly usedfor irrigation.Although large-volume syringes potentially allow sometime-savings, they are more difficult to control for pressure andaccidents may happen. Therefore, to maximize safety and control, useof 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 Dentals Flexi-Glide Utility Tips are disposable tipsthat are ideal for irrigation, application, and micro-aspiration. Constructed of polyimide tubing, Flexi-Glidesflexible, crimp-resistant tip facilitates access and providesmaximum 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 vibrationsthe use of EndoActivatorfacilitates irrigant penetration and mechanical cleansing compared withneedle irrigation, with no increase in the risk of irrigant extrusionthrough the apex.•
MULTIPLE BENEFITS SAFEStrong, flexible medical grade polymer tipsSingle patient useUncoated & non cutting tips • EFFECTIVECreate fluid hydrodynamicsImproves debridement and the disruption of the smear layerand biofilm • SIMPLEVery simple clinical techniqueIntuitive deviceIdeal in practice when portability is required
EndoVacthe EndoVac system is based on a negative-pressure approachwhereby the irrigant placed in the pulp chamber is sucked down theroot canal and back up again through a thin needle with a specialdesign
advantages• 1-the EndoVac system lowers the risks associated with irrigationclose 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