PowerPoint Presentation

Irrigation techniques

By

Ahmed Mostafa HusseinAssistant lecturer, Dental Biomaterials Department Faculty of Dentistry, Mansoura University2015

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IntroductionIn practice, current endodontic treatment uses two irrigants, sodium hypochlorite (NaOCl), alone or in combination with EDTA or chlorhexidine.All the instrumentation systems as well as current advancements in the instruments like nickel-titanium instruments and rotary can only clean the central body of the canal. Rest of the canal structures are untouched after completion of the preparation.Perhaps the most important factor is the delivery system and not the irrigating solution per se.(Walton and Torabinejad)

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Due to the safety factors, capacity of high volume irrigant delivery and ease of application the newer irrigation devices may change the insight of conventional endodontic treatment.Irrigation techniques might be divided into manual and machine-assisted techniques.3

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A. Manual irrigation techniques1. Syringe irrigation with needlesStill widely accepted by both general practitioners and endodontists.Either passively or with agitation. The agitation is achieved by moving the needle up and down the canal space.

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Needle: (length, bending, tip design)27 gauge needles are most commonly used. They should be bent to allow for easier access & entry into the orifice. Fitting of needle with syringe should be: Luer lock fit: include a screw-in lock for: a) easy removal b) secure attachment c) prevent accidental separation of needles from syringe.

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7Luer lock syringe

Needle tip design: 1) Open-end tips increase the apical pressure. 2) Closed-end tips are side-vented: * Improve the hydrodynamic activation of an irrigant. * Reduce the chance of apical extrusion.

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A-C: Open-ended needles; (A) flat, (B) beveled & (C) notched.D-F: Closed-ended needles; (D) side-vented, (E) double side- vented & (F) muti-vented.

Syringe: (material, size, design, number)Syringe material: syringes can be made of glass or plastic.Plastic syringes of different sizes (120 mL) are most commonly used for irrigation.Syringe size: large-volume syringes are time-saving, but they are more difficult to control for pressure and accidents may happen. * To maximize safety and control, using 15 mL syringes is recommended instead of the larger ones

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Syringe design: all syringes must have a Luer-Lok design.Number of syringes: separate syringes should be used for each irrigant to avoid chemical reactions between irrigants.Advantages of Syringe irrigation: easy to manipulate and good control over needle depth & volume of irrigant.Disadvantages: * Relatively weak flushing action. * In case of open apex: positive pressure could extrude the solution to the periapex. * Depth of irrigation: limited; 1 mm beyond the needle tip. 11

Precaution:Compressed air must not be used for drying the root canal because tissue emphysema may result if air penetrates the periapical tissue. Drying should be done with absorbent points.

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13Max-I-Probe needleMonoject needlesLuer-lockLuer-lockClosed-end & side-portOpen-endRounded tip & safe-endNotchedSafer irrigationHigher risk of apical extrusion of irrigant Thinner & more flexibleCan be used with curved canalsCan be used for endodontic & periodontal irrigationCan be used subgingivally

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Monoject: notchedMax-I-Probe: side-port

NaviTip needle:Safe rounded end.Rigid in the majority of the shank to prevent bending.The last few millimeters are flexible to facilitate navigation even through curved canals.

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2. Brushes (NaviTip FX & Endobrush)NaviTip FX:A 30-gauge irrigation needle covered with a brush.Improved cleanliness of the coronal third only when compared to brushless NaviTip needle.NaviTip FX brush bristles may dislodge inside the canal irregularities. It is very difficult to identify radiographically, because it is radiolucent.

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NaviTip FX

Endobrush:Consists of nylon bristles set in twisted wires with an attached handle.Could not be used to full working length, because of its size, which might lead to apical packing of debris.18

3. Manual-dynamic irrigationIt is often difficult for the irrigant to reach the apical portion of the canal because of the vapor lock effect.Gently moving well-fitting gutta-percha master cone up and down in short 2 to 3 mm strokes (manual-dynamic irrigation) within an instrumented canal: * can produce an effective hydrodynamic effect* can force the irrigant to the untouched canal surfaces.

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The laborious nature of this hand-activated procedure still hinders its application in routine clinical practice. Therefore, there are a number of automated devices designed for agitation of root canal irrigants.20

B. Machine-assisted irrigation techniques1) Rotary brushes (Ruddle brush and Canalbrush)Ruddle brush:Microbrush attached to a rotary handpiece.Has multiple bristles extending radially from a central wire core.Rotates at about 300 rpm.Displacing debris in a coronal direction.Has not been commercially available since the patent was approved in 2001.

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Ruddle brush

Canalbrush:Highly flexible microbrush.Molded entirely from polypropylene.Might be used manually with a rotary action.More effective when attached to contra-angle handpiece running at 600 rpm.23

2) Sonic irrigation (Rispisonic file, Endoactivator, Vibringe)Sonic irrigation is different from ultrasonic irrigation in:* Lower frequency (16 kHz). [Hertz (Hz) = cycles per second]* Smaller shear stresses. * Higher amplitude.

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Rispisonic file:The most aggressive sonic fileAggressive shaping.Because they are barbed, these files might damage the finished canal preparation during agitation.Material: stainless steel.Can be autoclaved.25

Endoactivator:Handpiece: Cordless, portable, battery operated.Polymer tips: Disposable (single use), smooth non-cutting, radiolucent, strong & flexible.Agitate irrigant solutions.

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Vibringe:Manual Syringe/needle irrigation + sonic vibration in one step.Handpiece: * Cordless. * Fits in a special disposable 10 ml Luer-Lock syringe.Battery: Rechargeable.Less effective than passive ultrasonic irrigation.27

3) Ultrasonic irrigationIntroduction:Ultrasonic is an adjective referring to ultrasound.Ultrasonic: means producing vibrations or sound waves with a frequency greater than the upper limit of human hearing (greater than 20 kHz).Methods for producing ultrasound: (2 types of ultrasonic units)* Magnetostrictive.* Piezoelectric: suitable for endodontic treatment.28

29PiezoelectricMagnetostrictiveelectrical charge is applied change in crystal size vibrationsElectromagnetic energy mechanical energy vibrationsLess heat generationMore heat generation, so cooling is requiredVibration of the tip is linear (back & front)Vibration of the tip is elliptical (eight figure)Frequency: 40 kHz (cycle per second)Frequency: 24 kHz (cycle per second)Ideal for endodontic treatment.

Ultrasonic irrigation produces higher frequencies (25- 30 kHz) & low amplitudes than sonic irrigation.Ultrasonic irrigation is better than sonic irrigation at removing dentin debris.Ultrasonic irrigation is more effective in wide canals.Ultrasonic handpieces pass sound waves to an endodontic file and cause it to vibrate at ~25,000 vibration/s. The best moment for ultrasonic activation of the irrigant is after shaping the root canal.

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Ultrasonics can effectively clean debris from the root canal, but cannot effectively get through the apical vapor lock, because acoustic microstreaming is only possible in fluids, not in gases. Free oscillation of the instrument will cause more ultrasonic effects in the irrigant solution than an oscillation forced against canal walls.Ultrasonic irrigation creates a higher speed of irrigant in the canal during irrigation, thereby eliminating more debris.It causes acoustic streaming and cavitation of the irrigant.

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Acoustic microstreaming and cavitation:Acoustic stream can be defined as a rapid movement of the fluid in a circular or vortex shape around the vibrating file. Cavitation is defined as the creation of steam bubbles or expansion, contraction and/or distortion of pre-existing bubbles in a liquid.32

Types of ultrasonic irrigation: a) Simultaneous combination of ultrasonic irrigation & instrumentation (UI). Note: simultaneous = happening at the same time. * This type has been almost discarded in the clinical practice, because it is difficult to control the cutting of dentin. b) Ultrasonic irrigation without simultaneous instrumentation. * It is called passive ultrasonic irrigation (PUI).33

Passive ultrasonic irrigation (PUI): agitating the irrigant solution previously placed inside the canal. An ultrasonic tip is activated in the canal up to working length and is moved passively in an up-and-down motion to ensure that it does not bind with the root canal walls.During PUI, energy is transmitted from a file or smooth oscillating wire to the irrigant by means of ultrasonic waves.Ultrasonic file can move freely in the canal, avoiding perforations.

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Acoustic streaming produces sufficient shear forces to dislodge debris in instrumented canals.Passive Ultrasonic irrigation (PUI) is more effective than Vibringe, UI & syringe irrigation in removing debris.The term passive here relates to non cutting action.A canal size of at least 30-40 file is required to maintain free oscillation. Ultrasonic Irrigation can be used as an intermittent irrigation or a continuous ultrasonic irrigation.

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Intermittent flushed ultrasonic irrigation:The irrigant is delivered to the root canal by a syringe needle. The irrigant is then activated with the use of an ultrasonically oscillating instrument.Continuous ultrasonic irrigation system:During ultrasonic activation, a 25-gauge irrigation needle is used instead of an endosonic file.The needle is simultaneously activated by the ultrasonic handpiece & maintains a continuous flow of fresh irrigant.

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4) Pressure alternation devices(negative-pressure irrigation)Examples:RinsEndo EndoVac

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RinsEndo:Irrigates the canal by using pressure-suction technology.It is composed of a handpiece, a cannula with a 7 mm exit aperture, and a syringe carrying irrigant. The irrigant is automatically drawn from the attached syringe and aspirated.The pressure-suction cycles change approximately 100 times per minute.Periapical extrusion of irrigant has been reported.

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RinsEndo

RinsEndo

EndoVac:An apical negative pressure irrigation system.Composed of three basic components:* Master Delivery Tip (MDT)* Macrocannula* Microcannula

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EndoVac

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MDTMicrocannula

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EndoVac

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A constant flow of fresh irrigant is being delivered by negative pressure to working length.Negative irrigation is better than positive pressure irrigation, because it prevents apical extrution of irrigant, provides better cleansing and has no vapor lock effect.EndoVac works on negative pressure, which draws irrigation apically through suction.The irrigant is delivered into the pulp chamber by the master delivery tip and is driven by negative pressure into the root canals with the aid of the macrocannula and microcannula.45

The manufacturers instructions must be followed for correct use of the Master Delivery Tip and to avoid creation of positive pressure in the pulp canal.

The flow of irrigant from the MDT should always be directed into an axial wall or the wall of pulp chamber and never directly into an orifice.

The EndoVac system requires a minimum canal shape:* No. 35 instrument with a 4% taper* or with a non-tapered system like LightSpeed, a size #45 at full working length.

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Advantages of EndoVac:Overcomes the apical vapor lock (air entrapment).The unique capability to deliver irrigants up to the working length (apical third) without the risk of apical extrution.Better debridement of apical third.A constant flow of fresh irrigant.Negative irrigation is better than positive pressure irrigation, because it prevents apical extrution of irrigant, provides better cleansing and has no vapor lock effect.47

Apical vapor lock:Definition: Air entrapment at the apical third by advancing the irrigant apically. It resists displacement during instrumentation and final irrigation.NaOCl reacts with organic material in the root canal and quickly forms micro air bubbles at the apical third that coalesce into an apical vapor lock with subsequent instrumentation.Acoustic microstreaming and cavitation are limited to liquids and have no effect inside the vapour lock. Acoustic microstreaming or cavitation is only possible in liquids, not in gases.

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Problems of apical vapor lock:Prevents the flow of irrigant into the apical region.Prevents adequate debridement of the canal system.How to overcome the vapor lock?Manual-dynamic irrigation: Hand-activated (moving up & down) well-fitting gutta-percha master cone that is introduced to working length after instrumentation. Apical negative pressure irrigation, such as EndoVac.

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5) Continuous irrigation during rotary instrumentationQuantec-E:It uses a pump console, 2 irrigation reservoirs and tubing It provides continuous irrigation during rotary instrumentation.Increased volume of irrigant.Cleaner canal walls in the coronal third only (compared with syringe irrigation with needles).

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VATEA system (Self adjusting file)Self Adjusting file (SAF), rotary system.It adjusts to the anatomy of the root canal.It has a hollow thin walled cylinder composed of a thin nickel-titanium lattice.Provides continuous irrigation during instrumentation.In oval canals, the SAF was found superior to rotary Ni-Ti files used with needle irrigation (NaOCl).SAF is designed to prepare root canals that do not have a round cross section.It has an abrasive surface.Up & down movement (vibration) during rotation.

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Self adjusting file (SAF)

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