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Safety and Efficacy Considerations in Endodontic IrrigationA Peer-Reviewed Publication Written by Gary Glassman DDS, FRCD(C)

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Educational ObjectivesThe overall goal of this article is to provide the reader with information on endodontic irrigation.

On completion of this course, the reader will be able to:1. List and describe the challenges for successful endodon-

tic treatment2. List and describe the different types of root canal irrig-

ants, their relative advantages and disadvantages3. List and describe root canal irrigation systems 4. Describe and explain a sodium hypochlorite incident5. List and describe the steps that can be taken to avoid a

sodium hypochlorite incident.

AbstractEndodontic treatment is a predictable procedure with high success rates. Success depends on a number of fac-tors, including appropriate instrumentation, successful irrigation and decontamination of the root canal space to the apices and in areas such as isthmuses. These steps must be followed by complete obturation of the root canals, and placement of a coronal seal, prior to restorative treatment. Several irrigants and irrigation systems are available, all of which behave differently and have relative advantages and disadvantages. Common root canal irrigants include sodium hypochlorite, chlorhexidine gluconate, alcohol, hydrogen peroxide and ethylenediaminetetraacetic acid (EDTA). In selecting an irrigant and technique, consid-eration must be given to their efficacy and safety.

IntroductionWith the introduction of modern techniques, end-odontic success rates of up to 98% are being achieved.1 The ultimate goal of endodontic treatment per se is the prevention or treatment of apical periodontitis such that there is complete healing and an absence of infec-tion,2 while the overall long-term goal is the placement of a definitive, clinically successful restoration and preservation of the tooth. For these to be achieved, appropriate instrumentation, irrigation and decon-tamination, and root canal obturation must occur, as well as attainment of a coronal seal. There is clear evidence that apical periodontitis is a biofilm-induced disease.3 A biofilm is an aggregate of microorganisms in which cells adhere to each other and/or to a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric sub-stance. The presence of microorganisms embedded in a biofilm and growing in the root canal system is a key factor for the development of periapical lesions.4,5,6,7 Additionally, the root canal system has a complex anatomy that consists of arborizations, isthmuses, and cul-de-sacs that harbor organic tissue and bacterial contaminants.8

The challenge for successful endodontic treatment has always been the removal of vital and necrotic remnants of pulp tissues, debris generated during instrumentation, the dentin smear layer, microorganisms, and microtoxins from the root canal system.9

Figure 1. Root canal complex

Courtesy of Dr. Charles J. Goodis. In: Mandibular Molar Endodontic Treatment.

Even with the use of rotary instrumentation, the nickel-tita-nium instruments currently available only act on the central body of the root canal, resulting in a reliance on irrigation to clean beyond what may be achieved by these instru-ments.10 In addition, Enterococcus faecalis and Actinomyces israelii—which are both implicated in endodontic infections as well as in endodontic failure—penetrate deep into the dentinal tubules, making their removal through mechanical instrumentation impossible.11,12 Finally, Enterococcus faecalis commonly expresses multiple drug resistance,13,14,15 further complicating treatment.

Therefore, a suitable irrigant and irrigant delivery sys-tem are essential for efficient irrigation and the success of endodontic therapy.16 Not only should root canal irrigants be effective for dissolution of the organic component of the dental pulp, they must also effectively eliminate bacterial contamination and remove the smear layer—the organic and inorganic layer that is created on the wall of the root canal during instrumentation. The ability to deliver irrigants to the root canal terminus in a safe manner without causing harm to the patient is as important as the efficacy of those irrigants.

Root Canal IrrigantsOver the years, many irrigating agents have been used and tried in order to achieve tissue dissolution and bacte-

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rial decontamination. The desired attributes of a root canal irrigant include the ability to dissolve necrotic and pulpal tissue, bacterial decontamination and a broad antimicrobial spectrum, the ability to enter deep into the dentinal tubules, biocompatibility and lack of toxicity, the ability to dissolve inorganic material and remove the smear layer, ease of use, and moderate cost.

Table 1. Desirable root canal irrigant attributes

Bacterial decontamination

Broad spectrum antimicrobial activity

Ability to enter deep into dentinal tubules

Ability to dissolve necrotic tissue

Ability to dissolve inorganic material

Safety

Biocompatibility

Lack of toxicity

Ease of use

Moderate cost

Root canal irrigants currently in use include hydrogen peroxide, sodium hypochlorite, ethylenediaminetetraace-tic acid (EDTA), alcohol, and chlorhexidine gluconate. Chlorhexidine gluconate offers a wide antimicrobial spec-trum, the main bacteria associated with endodontic infec-tions (Enterococcus faecalis and Actinomyces israelii) are sensitive to it, and it is biocompatible with no tissue toxicity for the periapical or surrounding tissues.17 Chlorhexidine gluconate, however, lacks the ability to dissolve necrotic tissue, which limits its usefulness. Hydrogen peroxide as a canal irrigant helps to remove debris by the physical act of irrigation as well as through effervescing of the solution. However, while an effective antibacterial irrigant, hydrogen peroxide also does not dissolve necrotic intracanal tissue, and exhibits toxicity to the surrounding tissues. Cases of tissue damage and facial nerve damage have been reported following use of hydrogen peroxide as a root canal irrigant.18 Alcohol-based canal irrigants also have antimicrobial activ-ity, but will not dissolve necrotic tissue.

Table 2. Common root canal irrigants

Chlorhexidine gluconateSodium hypochloriteAlcoholHydrogen peroxideEDTA

The irrigant that satisfies most of the requirements for a root canal irrigant is sodium hypochlorite (NaOCl).19,20 It has the unique ability to dissolve necrotic tissue and the

organic components of the smear layer.19,21,22 It also kills sessile endodontic pathogens organized in a biofilm.23,24 There is no other root canal irrigant that can meet all these requirements, even with the use of methods such as lower-ing the pH,25,26,27 increasing the temperature,28,29,30,31,32 or adding surfactants to increase the wetting efficacy of the ir-rigant.33,34 However, although sodium hypochlorite appears to be the most desirable single endodontic irrigant, it cannot dissolve inorganic dentin particles and thus cannot prevent the formation of a smear layer during instrumentation.35

Calcifications hindering mechanical preparation are frequently encountered in the canal system, further com-plicating treatment. Demineralizing agents such as EDTA have therefore been recommended as adjuvants in root canal therapy.20,36 Thus, in contemporary endodontic prac-tice, dual irrigants such as sodium hypochlorite (NaOCl) with EDTA are often used as initial and final rinses to cir-cumvent the shortcomings of a single irrigant.37,38,39 These irrigants must be brought into direct contact with the entire canal wall surfaces for effective action,20,37,40 particularly for the apical portions of small root canals.9

The combination of sodium hypochlorite and EDTA has been used worldwide for antisepsis of root canal sys-tems. The concentration of sodium hypochlorite used for root canal irrigation ranges from 2.5% to 6%, depending on the country and local regulations; it has been shown, however, that tissue hydrolyzation is greater at the higher end of this range, as demonstrated in a study by Hand et al comparing 2.5% and 5.25% sodium hypochlorite. The higher concentration may also favor superior microbial outcomes.41 NaOCl has a broad antimicrobial spectrum,20 including but not limited to Enterococcus faecalis. Sodium hypochlorite is also second to none among irrigating agents that dissolve organic matter. EDTA is a chelating agent that aids in smear layer removal and increases dentin perme-ability,42,43 which will allow further irrigation with NaOCl to penetrate deep into the dentinal tubules.44

The combination of sodium hypochlorite and EDTA has been used worldwide for antisepsis of root canal systems.

General Safety PrecautionsRegardless of which irrigant and irrigation system is em-ployed, and particularly if an irrigant with tissue toxicity is used, there are several general precautions that must be fol-lowed. A rubber dam must be used and a good seal obtained to ensure that no irrigant can spill from the pulp chamber into the oral cavity. If deep caries or a fracture is present adjacent to the rubber dam on the tooth being isolated, a temporary sealing material must be used prior to perform-ing the procedure to ensure a good rubber dam seal. It is also important to protect the patient’s eyes with safety glasses and protect clothing from irrigant splatter or spill.

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It is very important to note that while sodium hypochlo-rite has unique properties that satisfy most requirements for a root canal irrigant, it also exhibits tissue toxicity that can re-sult in damage to the adjacent tissues, including nerve dam-age should sodium hypochlorite incidents occur during canal irrigation. Furthermore, Salzgeber reported in the 1970s that apical extrusion of an endodontic irrigant routinely occurred in vivo;45 this highlights the importance of using devices and techniques that minimize or prevent this. Sodium hypochlo-rite incidents are further discussed later in this article.

Regardless of which irrigant and irrigation system is used, a rubber dam must be used and a good seal obtained.

Irrigant Delivery SystemsRoot canal irrigation systems can be divided into two catego-ries: manual agitation techniques and machine-assisted agita-tion techniques.9 Manual irrigation includes positive pressure irrigation, which is commonly performed with a syringe and a side-vented needle. Machine-assisted irrigation techniques include sonics and ultrasonics, as well as newer systems such as the EndoVac® (Discus Dental, Culver City, CA) , which delivers apical negative pressure (ANP) irrigation,46 the plas-tic rotary F® File (Plastic Endo, Lincolnshire, IL),47,48 the Vibringe® (Vibringe BV, Amsterdam, The Netherlands),49 the RinsEndo® (Air Techniques Inc., NY),9 and the Endo-Activator® (Dentsply Tulsa Dental Specialties, Tulsa, OK).9 Two important factors that should be considered during the process of irrigation are whether the irrigation system can deliver the irrigant to the whole extent of the root canal system, particularly at the apical third, and whether the ir-rigant is capable of debriding areas that could not be reached with mechanical instrumentation, such as lateral canals and isthmi. When evaluating irrigation of the apical third, the phenomenon of apical vapor lock should be considered.50,51,52

Apical Vapor LockSince roots are surrounded by the periodontium, and unless the root canal foramen is open, the root canal behaves like a close-ended channel. This produces an apical vapor lock effect that resists displacement during instrumentation and final irrigation, thus preventing the flow of irrigant into the apical region and adequate debridement of the canal system.53,54 Apical vapor lock also results in gas entrapment at the apical third.9 During irrigation, sodium hypochlorite reacts with organic tissue in the root canal system, and the resulting hydrolysis liberates abundant quantities of ammonia and carbon dioxide.55 This gaseous mixture is trapped in the apical region and quickly forms a column of gas into which further fluid penetration is impossible. Extension of instruments into this vapor lock does not re-duce or remove the gas bubble,56 just as it does not enable adequate flow of irrigant.

Apical vapor lock prevents the flow of irrigant into the apical region of roots and also results in gas

entrapment at the apical third.

The phenomenon of apical vapor lock has been confirmed in studies where roots were embedded in a polyvinylsiloxane (PVS) impression material to restrict fluid flow through the apical foramen, simulating a close-ended channel. The result in these studies was incomplete debridement of the apical part of the canal walls with the use of a positive pressure syringe delivery technique.57,58,59,60 Micro-CT scanning and histological tests conducted by Tay et al have also confirmed the presence of apical vapor lock.60 In fact, studies conducted without ensuring a close-ended channel cannot be regarded as conclusive on the efficacy of irrigants and the irrigant sys-tem.61,62,63 The apical vapor lock may also explain why, in a number of studies, investigators were unable to demonstrate a clean apical third in sealed root canals.59,64,65,66

Figure 2a. Close-ended channel Figure 2b. Open-ended channel

Courtesy of Dr. Franklin Tay

In a paper published by Chow in 1983, based on research he determined that traditional positive pressure irrigation had virtually no effect apical to the orifice of the irrigation needle in a closed root canal system.67 Fluid exchange and debris displacement were minimal. Equally important to his primary findings, Chow set forth an infallible paradigm for endodontic irrigation: “For the solution to be mechanically effective in removing all the particles, it has to: (a) reach the apex; (b) create a current (force); and (c) carry the particles away.”67 The apical vapor lock and consideration for the pa-tient’s safety have always prevented the thorough cleaning of the apical 3 mm. It is critically important to determine which irrigation system will effectively irrigate the apical third as well as isthmi and lateral canals,16 and in a safe manner that prevents the extrusion of irrigant.

An effective irrigant must reach the apex, create a current and remove particles.

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Manual Agitation TechniquesBy far the most common and conventional set of irrigation techniques, manual irrigation involves dispensing of an ir-rigant into a canal through needles/cannulae of variable gauges, either passively or with agitation by moving the needle up and down the canal space without binding it on the canal walls. This allows good control of needle depth and the volume of irrigant that is flushed through the canal.9,63 However, the closer the needle tip is positioned to the apical tissue, the greater the chance of apical extrusion of the irrig-ant.67,68 This must be avoided; if sodium hypochlorite were to extrude past the apex there is a chance that a catastrophic accident could occur.69

Manual-Dynamic Irrigation Manual dynamic irrigation involves gently moving a well-fit-ting gutta-percha master cone up and down in short 2 mm to 3 mm strokes within an instrumented canal, thereby produc-ing a hydrodynamic effect and significant irrigant exchange.70

Recent studies have shown that this irrigation technique is significantly more effective than an automated-dynamic ir-rigation system and static irrigation.9,71,72

Figure 3. Manual Dynamic Max-I-Probe®

Machine-Assisted Agitation Systems

Sonic IrrigationSonic activation has been shown to be an effective method for disinfecting root canals, operating at frequencies of 1-6 kHz.73,74 There are several sonic irrigation devices on the market. The Vibringe allows delivery and sonic activation of the irrigating solution in one step. It employs a 2-piece syringe with a rechargeable battery. The irrigant is soni-cally activated, as is the needle that attaches to the syringe. The EndoActivator System is a more recently introduced sonically driven canal irrigation system. 9,75 It consists of a portable handpiece and three types of disposable polymer tips of different sizes. The EndoActivator has been reported to effectively clean debris from lateral canals, remove the smear layer, and dislodge clumps of biofilm within the curved canals of molar teeth.9

Figure 4. Sonic irrigation systems

UltrasonicsUltrasonic energy produces higher frequencies than sonic energy but low amplitudes, oscillating at frequencies of 25-30 kHz.9,76 Two types of ultrasonic irrigation are available for use. The first type is simultaneous ultrasonic instrumen-tation and irrigation (UI), and the second type is referred to as passive ultrasonic irrigation operating without simul-taneous irrigation (PUI). The literature indicates that it is more advantageous to apply ultrasonics after completion of canal preparation rather than as an alternative to conven-tional instrumentation.9,20,77 PUI irrigation allows energy to be transmitted from an oscillating file or smooth wire to the irrigant in the root canal by means of ultrasonic waves.9 There is consensus that PUI is more effective than syringe .needle irrigation in removing pulpal tissue remnants and dentin debris.78,79,80 This may be due to the much higher velocity and volume of irrigant flow that are created in the canal during ultrasonic irrigation.9,81 PUI has been shown to remove the smear layer; there is a large body of evidence with different concentrations of NaOCl.9,80,82,83,84 In addi-tion, numerous investigations have demonstrated that the use of PUI after hand or rotary instrumentation results in a significant reduction of the number of bacteria,9,85,86,87 or achieves significantly better results than syringe needle ir-rigation.9,84,88,89

Studies have demonstrated that effective delivery of irri-gants to the apical third can be enhanced by using ultrasonic and sonic devices.79,81,90,91,92 However, some recent studies have shown that once a sonic or ultrasonically activated tip leaves the irrigant and enters the apical vapor lock, acous-tic microstreaming and/or cavitation becomes physically impossible,93 which is not the case with the apical negative pressure irrigation technique.46,94

Consider the erroneous idea that acoustic microstream-ing or cavitation that occurs during PUI can clean any part of the apical portion filled with gas (apical vapor lock). Acoustic microstreaming is defined as the movement of fluids along cell membranes, which occurs as a result of the ultra-sound energy creating mechanical pressure changes within the tissue. Cavitation is defined as the formation and col-lapse of gas- and vapor-filled bubbles or cavities in a fluid.

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This process (cavitation) results from the creation and col-lapse of microbubbles in the liquid. Acoustic microstream-ing or cavitation is only possible in fluids/liquids, not in gases. Therefore, as previously mentioned, it is physically impossible for acoustic microstreaming and/or cavitation to disrupt the apical vapor lock..56

Other studies have shown that sonic or ultrasonic activa-tion might allow a better removal of pulpal tissue remnants and debris from isthmi and fins.79,81 Although ultrasonics can effectively clean debris and bacteria from the root canal system, they still have the drawback of not being able to effectively get through the apical vapor lock in the apical 3 mm of the canal.

Ultrasonics can effectively clean debris and bacteria from the root canal system, but cannot effectively get through

the apical vapor lock.

The Plastic Rotary F FileAlthough sonic or ultrasonic instrumentation is more effec-tive in removing residual canal debris than rotary endodontic files95 and irrigation solutions are often unable to remove this during endodontic treatment, many clinicians still do not incorporate it in their endodontic instrument armamen-tarium. The common reasons given for not using sonic or ultrasonic filing are that it can be time-consuming to set up, an unwillingness to incur the cost of the equipment, and lack of awareness of the benefits of this final instrumentation step in endodontic treatment.

It is for these reasons that an endodontic polymer-based rotary finishing file was developed. This new, single-use, plastic rotary file has a unique file design with a diamond abrasive embedded into a nontoxic polymer. The F File will remove dentinal wall debris and agitate the sodium hypochlo-rite without further enlarging the canal.

Pressure Alternation DevicesRinsEndo irrigates the canal by using pressure-suction technology. Its components are a handpiece, a cannula with a 7 mm exit aperture, and a syringe carrying irrigant. The handpiece is powered by a dental air compressor and has an irrigation speed of 6.2 ml/min. Research has shown that it has promising results in cleaning the root canal system, but more research is required to provide scientific evidence for its efficacy. Periapical extrusion of irrigant has been reported with this device.96,97

Figure 5. RinsEndo

The EndoVac Apical Negative Pressure SystemThe EndoVac apical negative pressure irrigation system has three components: The Master Delivery Tip, MacroCannula and MicroCannula. The Master Delivery Tip simultaneously delivers and evacuates the irrigant. The MacroCannula is used to suction irrigant from the chamber to the coronal and middle segments of the canal. The MacroCannula or MicroCannula is connected via tubing to the high-speed suction of a dental unit. The Master Delivery Tip is connected to a syringe of ir-rigant and the evacuation hood is connected via tubing to the high-speed suction of a dental unit.56 The plastic MacroCan-nula has an ISO size 0.55 mm diameter open end with a .02 taper and is attached to a Handpiece for gross, initial flushing of the coronal and mid-length parts of the root canal. The MicroCannula contains 12 microscopic holes and is capable of evacuating debris to full working length.97 The ISO size 0.32 mm diameter stainless steel MicroCannula has four sets of three laser-cut, laterally positioned, offset holes adjacent to its closed end, 100 microns in diameter and spaced 100 microns apart. This is attached to a Fingerpiece for irrigation of the api-cal part of the canal when it is positioned at the working length. The MicroCannula can be used in canals that are enlarged with endodontic files to ISO size #35/.04 or larger.

Figure 6a. EndoVac Multi-Port Adapter

Figure 6b. EndoVac instruments

Master Delivery Tip

MacroCannula

MicroCannula with venting

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During irrigation, the Master Delivery Tip delivers irrigant to the pulp chamber and siphons off the excess irrigant to prevent overflow. Both the MacroCannula and MicroCan-nula exert negative pressure that pulls irrigant from its fresh supply in the chamber, down the canal to the tip of the can-nula, into the cannula, and out through the suction hose. Thus, a constant flow of fresh irrigant is being delivered by negative pressure to working length. A recent study showed that the volume of irrigant delivered was significantly higher than the volume delivered by conventional syringe needle irrigation during the same time period,46 and resulted in significantly more debris removal at 1 mm from the working length than did needle irrigation. During conventional root canal irrigation, clinicians must be careful when determin-ing how far an irrigation needle is placed into the canal. Recommendations for avoiding NaOCl incidents include not binding the needle in the canal, not placing the needle close to working length, and using a gentle flow rate when using positive pressure irrigation.98 With the EndoVac, in contrast, irrigant is pulled into the canal at working length and removed by negative pressure. Apical negative pres-sure has been shown to enable irrigants to reach the apical third and help overcome the issue of apical vapor lock.46,99 In addition, with respect to isthmus cleaning, although it is not possible to reach and clean the isthmus area with instru-ments, it is not impossible to reach and totally clean these areas with NaOCl when the method of irrigation is safe and efficacious. In studies comparing the EndoActivator,100 passive ultrasonic,100 the F File,100 the Manual Dynamic

Max-I-Probe, 100,101 the Pressure Ultrasonic,95 and the En-doVac,101 only the EndoVac was capable of cleaning 100% of the isthmus area.

The EndoVac uses negative pressure, pulls irrigant into the canal to working length and

removes it with suction.

Apart from being able to avoid air entrapment, the EndoVac system is also advantageous in its ability to safely deliver irrigants to working length without causing their undue extrusion into the periapex,46,97 thereby avoiding sodium hypochlorite incidents. It is important to note that it is possible to create positive pressure in the pulp canal if the Master Delivery Tip is misused, which would create the risk of a sodium hypochlorite incident. The manufacturer’s instructions must be followed for correct use of the Master Delivery Tip.

Sodium Hypochlorite IncidentsAlthough a devastating endodontic sodium hypochlorite (Na-OCl) incident is a rare event,102 the cytotoxic effects of sodium hypochlorite on vital tissue have been well established.103 The associated sequelae of NaOCl extrusion have been reported to include life-threatening airway obstructions,104 facial disfig-

urement requiring multiple corrective surgical procedures,105 permanent paresthesia with loss of facial muscle control,69 and—the least significant consequence—tooth loss.106

Table 2. Potential sequelae of sodium hypochlorite extrusion through the apex

EcchymosisWidespread tissue traumaTooth lossFacial disfigurementPermanent paresthesiaLoss of facial muscle controlIrreversible muscle atrophyLife-threatening airway obstruction

Although the exact etiology of the NaOCl incident is still uncertain, based on the evidence from actual incidents and the location of the associated tissue trauma, it would appear that an intravenous injection may be the cause. The patient shown in Figure 7 demonstrates a widespread area of tissue trauma that is in contrast to the characteristics of sodium hypochlorite incident trauma reported by Pash-ley.103,107 This extensive trauma, and particularly involving the pattern of ecchymosis around the eye, could only occur if the sodium hypochlorite were introduced intravenously to a vein close to the root apex through which extrusion of the irrigant occurred, and the irrigant then found its way into the venous complex. This would require positive pressure apically that exceeded venous pressure (10 mg of Hg). In one in vitro study, which used a positive pressure needle ir-rigation technique to realistically mimic clinical conditions and techniques, the apical pressure generated was found to be 8 times higher than the normal venous pressure.108

Figure 7. Widespread tissue trauma

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Figure 8. Irreversible musculature atrophy

This does not imply that NaOCl can or should be excluded as an endodontic irrigant; in fact, its use is critical, as has been discussed in this article. What this does imply is that it must be safely delivered.

Safety FirstTo compare the safety of six current intracanal irrigation de-livery devices, an in vitro test was conducted using the worst-case scenario of apical extrusion, with neutral atmospheric pressure and an open apex.97 The study concluded that the EndoVac did not extrude irrigant after deep intracanal de-livery and suctioning of the irrigant from the chamber to full working length, whereas other devices did. The EndoActiva-tor extruded only a very small volume of irrigant, the clinical significance of which is not known.

Figure 9. Comparative extrusion of irrigant using irrigation devices100

80

60

40

20

0

Irrigation system used

Extr

usi

on

of i

rrig

ant (

%)

MicroCannula

EndoActivator

Max-I-Probe

Positive Pressu

re

Ultraso

nic RinsEndo

MacroCannula

Mitchell and Baumgartner tested irrigant (NaOCl) extrusion from a root canal sealed with a permeable agarose gel.109 Sig-nificantly less extrusion occurred using the EndoVac system compared with positive pressure needle irrigation. A well-con-trolled study by Gondim et al found that patients experienced less postoperative pain, measured objectively and subjectively,

when apical negative pressure irrigation was performed (En-doVac) rather than apical positive pressure irrigation.110

The use of apical negative pressure needle irrigation results in safer delivery of sodium hypochlorite, and less

post-operative pain.

EfficacyIn vitro and in vivo studies have demonstrated greater removal of debris from the apical walls and a statistically cleaner result using apical negative pressure irrigation in closed root canal systems with sealed apices. In an in vivo study of 22 teeth by Siu and Baumgartner, less debris remained at 1 mm from working length using apical negative pressure compared to use of traditional needle irrigation, while Shin et al found in an in vitro study of 69 teeth comparing traditional needle irrigation with apical negative pressure that these methods both resulted in clean root canals but that apical negative pressure resulted in less debris remaining at 1.5 mm and 3.5 mm from working length.46, 99,111 When comparing root canal debridement using manual dynamic agitation or the EndoVac for final irrigation in a closed system and an open system, it was found that the presence of a sealed apical foramen adversely affected debride-ment efficacy when manual dynamic agitation was used, but did not adversely affect results when the EndoVac was used. Apical negative pressure irrigation is an effective method to overcome the fluid dynamic challenges inherent in closed canal systems.112

Apical negative pressure irrigation results in greater removal of debris and a cleaner result at working length.

Microbial ControlHockett et al tested the ability of apical negative pressure to remove a thick biofilm of Enterococcus faecalis, finding that these specimens rendered negative cultures obtained within 48 hours while those irrigated using traditional positive-pressure irrigation were positive at 48 hours.94 Figure 10 shows a scanning electron microscope image of decontami-nated dentinal tubules after use of apical negative pressure irrigation with sodium hypochlorite and use of EDTA.

Figure 10. SEM of decontaminated dentinal tubules

Courtesy of Dr. Jeffrey L. Hockett and Dr. Nestor Cohenca

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One study found apical negative pressure irrigation resulted in similar bacterial reductions to use of apical posi-tive pressure irrigation and a triple antibiotic in immature teeth.113 In a study comparing the use of apical positive pressure irrigation and a triple antibiotic that has been utilized for pulpal regeneration/revascularization in teeth with incompletely formed apices (Trimix=Cipro, Minocin, Flagyl) versus use of apical negative pressure irrigation with sodium hypochlorite, it was found that the results were sta-tistically equivalent for mineralized tissue formation and the repair process.114 Using negative apical pressure and sodium hypochlorite also avoids the risk of drug resistance, tooth discoloration, and allergic reactions.115,116

ConclusionSince the dawn of contemporary endodontics, dentists have been syringing sodium hypochlorite into the root canal space and then proceeding to place endodontic instruments down the canal in the belief that they were carrying the irrigant to the apical termination. Biological, SEM, light microscopy, and other studies have proven this belief to be in error. Sodium hypochlorite reacts with organic material in the root canal and quickly forms micro gas bubbles at the apical termination that coalesce into a single large apical vapor bubble with subsequent instrumentation. Since the apical vapor lock cannot be displaced via mechanical means, it prevents further sodium hypochlorite flow into the apical area. Additionally, acoustic microstreaming and cavitation are limited to liquids and have no effect inside the vapor lock. The only method yet discovered to eliminate the apical vapor lock is to evacuate it via apical negative pressure. This method has also been proven to be safe because it always draws irrigants to the source via suction—down the canal and simultaneously away from the apical tissue in abun-dant quantities.117 When the proper irrigating agents are delivered safely to the full extent of the root canal terminus, thereby removing 100% of organic tissue and 100% of the microbial contaminants, success in endodontic treatment may be taken to levels never seen before.

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16 deGregorioC,EstevezR,CisnerosR,ParanjpeA,CohencaN.Efficacyofdifferentirrigationandactivationsystemsonthepenetrationofsodiumhypochloriteintosimulatedlateralcanalsanduptoworkinglength:Aninvitrostudy. J Endod.2010;36(7):1216-21.

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59 Albrecht LJ, Baumgartner JC, Marshall JG. Evaluationof apical debris removal using various sizes and tapers ofProFileGTfiles.J Endod.2004;30:425-8.

60 TayFR,GuLS,SchoeffelGJ,etal.Effectofvaporlockonrootcanaldebridementbyusingaside-ventedneedleforpositive-pressureirrigantdelivery.J Endod.2010;36(4):745-50.

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63 vanderSluisLW,GambariniG,WuMK,WesselinkPR.Theinfluenceofvolume,typeofirrigantandflushingmethodonremoving artificially placed dentine debris from the apicalrootcanalduringpassiveultrasonicirrigation.Int Endod J.2006;39(6):472-6.

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72 HuangTY,GulabivalaK,NgY-L.Abio-molecularfilmex-vivomodeltoevaluatetheinfluenceofcanaldimensionsandirrigationvariablesontheefficacyofirrigation.Int Endod J.2008;41:60-71.

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79 Goodman A, Reader A, Beck M, Melfi R, Meyers W.An in vitro comparison of the efficacy of the step-backtechniqueversusastep-back/ultrasonictechniqueinhumanmandibularmolars.J Endod.1985;11:249-56.

80 Cameron JA. The synergistic relationship betweenultrasound and sodium hypochlorite: a scanning electronmicroscopeevaluation.J Endod.1987;13:541-5.

81 LeeSJ,WuMK,WesselinkPR.Theeffectivenessofsyringeirrigationandultrasonics to removedebris fromsimulatedirregularitieswithinpreparedrootcanalwalls.Int Endod J.2004;37:672-8.

82 Cameron JA.The use of ultrasonics in the removal of thesmearlayer:ascanningelectronmicroscopestudy.J Endod.1983;9:289-92.

83 AlacamT.Scanningelectronmicroscopestudycomparingthe efficacy of endodontic irrigating systems. Int Endod J. 1987;20:287-94.

84 HuqueJ,KotaK,YamagaM,IwakuM,HoshinoE.Bacterialeradication from root dentine by ultrasonic irrigation withsodiumhypochlorite.Int Endod J.1998;31:242-50.

85 Martin H, Cunningham WT, Norris JP, Cotton WR.Ultrasonicversushandfilingofdentin:aquantitativestudy.Oral Surg Oral Med Oral Pathol. 1980;49:79-81.

86 CunninghamWT,MartinH,ForrestWR.Evaluationofrootcanal debridement by the endosonic ultrasonic synergisticsystem.Oral Surg Oral Med Oral Pathol.1982;53:401-4.

87 CunninghamWT,MartinH,PelleuGBJr.,StoopsDE.Acomparisonofantimicrobialeffectivenessofendosonicandhandrootcanaltherapy.Oral Surg Oral Med Oral Pathol.1982;54:238-41.

88 SpoletiP,SiragusaM,SpoletiMJ.Bacteriologicalevaluationofpassiveultrasonicactivation.J Endod.2003;29:12-4.

89 Weber CD, McClanahan SB, Miller GA, Diener-West M,Johnson JD. The effect of passive ultrasonic activation of2% chlorhexidine or 5.25% sodium hypochlorite irriganton residual antimicrobial activity in root canals. J Endod.2003;29:562-4.

90 Cameron JA. The use of 4 per cent sodium hypochlorite,with or without ultrasound, in cleansing of uninstrumentedimmaturerootcanals:SEMstudy.Aust Dent J.1987;32:204-13.

91 Metzler RS, Montgomery S. Effectiveness of ultrasonicsand calcium hydroxide for the debridement of humanmandibularmolars.J Endod.1989;15:373-8.

92 Cheung GS, Stock CJ. In vitro cleaning ability of rootcanal irrigants with and without endosonics. Int Endod J.1993;26:334-43.

93 SchoeffelGJ.TheEndoVacmethodofendodonticirrigation,part3:systemcomponentsandtheirinteraction.Dent Today.2008;27(106):8-11.

94 Hockett JL, Dommisch JK, Johnson JD, Cohenca N.Antimicrobialefficacyoftwoirrigationtechniquesintaperedand nontapered canal preparations: an in vitro study. J

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debridementefficacyofultrasonicirrigationfollowinghand-rotary instrumentation in human mandibular molars. J Endod.2005;3:166-170.

96 PouchD,BohneW,etal.CleaningqualitiesofRinsendo:aninvitrostudy.Eur Cells Mater.2007;13:7.

97 DesaiP,HimelV.Comparativesafetyofvarious intracanalirrigationsystems.J Endod.2009;35(4):545-9.

98 Hülsmann M, HahnW. Complications during root canalirrigation: literature review and case reports. Int Endod J.2000;33:186-93.

99 Shin SJ, Kim HK, Jung IY, Lee CY, Lee SJ, Kim E.Comparisonofthecleaningefficacyofanewapicalnegativepressure irrigating system with conventional irrigationneedlesintherootcanals.Oral Surg Oral Med Oral Pathol Oral Radiol Endod.2010Mar;109(3):479-84.

100KlynSL,KirkpatrickTC,RutledgeRE.InvitrocomparisonsofdebrisremovaloftheEndoActivatorSystem,theFFile,ultrasonicirrigation,andNaOClirrigationaloneafterhand-rotary instrumentation in human mandibular molars. J Endod.2010;36(8):1367-71.

101SusinL,ParenteJM,LoushineRJ,etal.Canalandisthmusdebridementefficaciesoftwoirrigantagitationtechniquesinaclosedsystem.Int Endod J.2010;43(12):1077-90.

102Mehdipour O, Kleier DJ, Averbach RE. Anatomy ofsodiumhypochloriteaccidents.Compend Contin Educ Dent. 2007;28(10):544-6.

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104BowdenJR,EthunandanM,BrennanPA.Life-threateningairway obstruction secondary to hypochlorite extrusionduring root canal treatment. Oral Surg Oral Med Oral Pathol Oral Radiol Endod.2006;101(3):402-4.

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108Boutsioukis C, Verhaagen B, Versluis M, Kastrinakis E,Wesselink PR, van der Sluis PR. Evaluation of irrigantflow in the root canal using different needle types by anunsteady computational fluid dynamics model. J Endod.2010;36(5):875-97.

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Author ProfileGary Glassman DDS, FRCD(C)Dr. Gary Glassman graduated from the University of Toronto School of Dentistry in 1984 and graduated from the Endodontology Program at Temple University in 1987 where he received the Louis I. Grossman Study Club Award for academic and clinical proficiency in End-

odontics. The author of numerous publications, Dr. Glass-man lectures globally on endodontics and is on staff at the University of Toronto, Faculty of Dentistry in the graduate department of endodontics. Gary is a Fellow of the Royal College of Dentists of Canada, and the endodontic editor for Oral Health dental journal. He maintains a private prac-tice, Endodontic Specialists, in Toronto, Ontario, Canada. He can be reached through his website www.rootcanals.ca.

DisclaimerThe author of this course has no commercial ties with the sponsors or the providers of the unrestricted educational grant for this course.

Reader FeedbackWe encourage your comments on this or any PennWell course. For your convenience, an online feedback form is available at www.ineedce.com.

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Questions

1.Endodonticsuccessratesofupto_______arebeingachieved.a. 68%b. 78%c. 88%d. 98%

2.Thereisclearevidencethatapicalperiodontitisisa_______disease.a. fungalb. viralc. biofilm-induced d. all of the above

3.Therootcanalsystemcontains_______.a. cul-de-sacs b. arborizations c. isthmuses d. all of the above

4._______fromtherootcanalisoneofthechallengesforsuccessfulendodontictreatment.a. The removal of pulp tissueb. The removal of debris and the smear layerc. The removal of microorganisms and microtoxinsd. all of the above

5.Thenickel-titaniuminstrumentscur-rentlyavailableactonthe_______oftherootcanal.a. isthmib. central bodyc. lateral bodyd. all of the above

6._______penetratesdeepintothedentinaltubules.a. Actinomyces israeliib. Candida albicansc. Enterococcus faecalisd. a and c

7.Tobeeffective,rootcanalirrigantsmust_______.a. eliminate bacterial contamination b. remove the smear layer c. dissolve the organic component of the dental pulpd. all of the above

8._______isadesiredattributeforarootcanalirrigant.a. Bacterial decontaminationb. A broad antimicrobial spectrumc. The ability to enter deep into dentinal tubulesd. all of the above

9._______iscurrentlyusedasarootcanalirrigant.a. Chlorhexidine gluconateb. Hydrogen peroxidec. Sodium hypochlorited. all of the above

10.Chlorhexidinegluconate_______.a. offers a wide antimicrobial spectrum b. is biocompatible c. lacks the ability to dissolve necrotic tissue d. all of the above

11.Hydrogenperoxide_______.a. is an effective antibacterial irrigant b. exhibits no tissue toxicityc. dissolves necrotic tissued. a and c

12.Theirrigantthatsatisfiesmostoftherequirementsforarootcanalirrigantis_______.a. polyalkenoic acidb. sodium hypochlorite c. salined. chlorhexidine gluconate

13.Sodiumhypochlorite_______.a. dissolves necrotic tissue b. dissolves the organic components of the smear

layerc. kills sessile endodontic pathogensd. all of the above

14.EDTAhasbeenrecommendedasanadjuvantinrootcanaltherapybecauseitisa_______.a. remineralizing agentb. dilutantc. demineralizing agentd. b and c

15.Thecombinationof_______hasbeenusedworldwideforantisepsisofrootcanalsystems.a. sodium hypochlorite and calcium chlorideb. EDTA and chlorhexidine gluconatec. sodium hypochlorite and EDTA d. all of the above

16._______isageneralsafetyprecautionpriortorootcanalirrigation.a. Use of a rubber damb. Protecting the patient’s eyes with safety glassesc. Use of a temporary sealing material if deep caries is

present adjacent to a rubber damd. all of the above

17.Apicalextrusionofanendodonticirrigant_______occurs.a. neverb. rarelyc. routinelyd. always

18.Rootcanalirrigationsystemsareavail-ablethatworkusing_______.a. manual agitation techniques b. manual rotation techniques c. machine-assisted agitation techniques d. a and c

19.Whenirrigatingtherootcanalsystem,itisimportanttoconsiderif_______.a. the irrigation system can deliver the irrigant to the

whole extent of the root canal systemb. the irrigant can debride areas that cannot be

reached mechanicallyc. the irrigant contains any dyed. a and b

20.Anapicalvaporlockeffect_______.a. prevents the flow of irrigant into the apical region of

the root canal b. results in gas entrapment at the apical third c. resists displacement by instrumentationd. all of the above

21.The_______ofsodiumhypochloriteliberatesammoniaandcarbondioxide.a. dessicationb. hydrolysis c. cross-linkingd. none of the above

22.Anapicalvaporlockoccursinrootcanalswith_______.a. an open-ended channelb. a close-ended channelc. multiple isthmusesd. all of the above

23._______haveconfirmedthepresenceofapicalvaporlock.a. Histological tests b. Micro-CT scansc. Radiographsd. a and b

24.Forarootcanalirriganttobemechanicallyeffectiveinremovingalltheparticles,ithasto_______.a. reach the apex b. create a current c. carry the particles away d. all of the above

25.Theapicalvaporlockandconsiderationforthepatient’ssafetyhasalwayspreventedthethoroughcleaningofthe_______.a. apical 3 mm b. lateral 3 mmc. apical 5 mm d. lateral 5 mm

26.Themostcommonandconventionalsetofirrigationtechniquesis_______.a. mechanical irrigation b. manual irrigation c. hydrodynamic theory irrigation d. all of the above

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Questions

27.Manualdynamicirrigationproduces_______.a. a hydrodynamic effect b. effervescencec. significant irrigant exchange d. a and c

28.Sonicactivationhasbeenshowntobeaneffectiverootcanalirrigationmethod,operatingatfrequenciesof_______.a. 1-6 kHz b. 2-7 kHz c. 3-8 kHz d. none of the above

29.Ultrasonicenergy_______.a. produces higher frequencies than sonic energy b. produces low amplitudes c. results in oscillations at frequencies of 25-30 kHzd. all of the above

30.Theliteratureindicatesthatitismoreadvantageoustoapplyultrasonics_______.a. as an alternative to conventional instrumentation b. after completion of canal preparation c. after initial root canal preparationd. a and c

31.Passiveultrasonicirrigation_______.a. operates without simultaneous irrigation b. allows energy to be transmitted from an oscillating

file or smooth wire to the irrigant c. is the only type of ultrasonic irrigationd. a and b

32.Passiveultrasonicirrigation_______.a. effectively removes pulpal tissue remnantsb. effectively removes dentin debrisc. results in a significant reduction of the number of

bacteriad. all of the above

33.Studieshavedemonstratedthateffectivedeliveryofirrigantstotheapicalthirdcanbeenhancedbyusing_______devices.a. ultrasonic b. sonicc. air abrasiond. a and b

34.Acousticmicrostreamingisdefinedasthemovementof_______.a. sound along cell membranes b. fluids along cell membranes c. gases along cell membranesd. all of the above

35.Onceasonicorultrasonicallyactivatedtipleavestheirrigantandenterstheapicalvaporlock,_______becomesphysicallyimpossible.a. acoustic microstreaming b. cavitation c. cell deathd. a and/or b

36.Ultrasonics_______.a. can effectively clean bacteria from the root canal

systemb. can effectively clean debris from the root canal

systemc. cannot effectively get through the apical vapor lockd. all of the above

37._______isacommonreasongivenfornotusingsonicorultrasonicfiling.a. The time required for set-upb. An unwillingness to incur the equipment costsc. Lack of awareness of the benefits of this final

instrumentation stepd. all of the above

38.Sonicorultrasonicactivationmightallowabetterremovalof_______.a. pulpal tissue remnants b. debris from isthmi c. debris from finsd. all of the above

39.Anapicalnegativepressuresystemcontainsa_______.a. Master Delivery Tipb. MacroCannulac. MicroCannulad. all of the above

40.Apressurealternationdeviceconsistsof_______.a. a handpieceb. a cannula with a 7 mm exit aperture c. a syringe carrying irrigantd. all of the above

41.Withanapicalnegativepressuresystem,thecannulaeinthecanal_______.a. exert negative pressureb. pull irrigant from its fresh supply in the

chamber, down the canal to the tip of the cannula

c. pull irrigant into the cannula and out through the suction hose

d. all of the above

42.Apicalnegativepressurehasbeenshownto_______.a. enable irrigants to reach the apical third b. help overcome the issue of apical vapor lock c. remove the risk of sodium hypochlorite incidentsd. all of the above

43.Asodiumhypochloriteincidentoccurswhentheirrigant_______.a. extrudes through the root canal foramenb. is at a concentration above 3%c. is mixed with a second irrigantd. all of the above

44.Recommendationsforavoidingsodiumhypochloriteincidentsinclude_______.a. not binding the needle in the canal b. not placing the needle close to working length

c. using a gentle flow rate

d. all of the above

45._______isasequelaofasodiumhypochloriteincident.a. Life-threatening airway obstruction

b. Permanent paresthesia

c. Facial disfigurement

d. all of the above

46.Basedontheevidencefromactualsodiumhypochloriteincidentsandthelocationoftheassociatedtissuetrauma,itwouldappearthatan_______maybethecause.a. anatomical anomaly

b. intravenous injection

c. arterial injection

d. a and b

47.Inaninvitrostudycomparingintracanalirrigationdeliverydevices,onlytheuseofadeviceusing_______resultedinnoextrusionattheapex.a. ultrasonics

b. apical positive pressure

c. apical negative pressure

d. sonics

48.Thepresenceofasealedapicalforamenwasshowninonestudytoadverselyaffectdebridementefficacywhen_______wasused.a. manual dynamic agitation

b. apical negative pressure

c. water

d. all of the above

49.Theonlymethodyetdiscoveredtoeliminatetheapicalvaporlockistoevacuateitvia_______.a. apical positive pressure

b. apical negative pressure

c. acoustic microstreaming

d. all of the above

50.Properrootcanalirrigationshouldresultin_______.a. safe delivery of the irrigating agent(s)

b. removal of 100% of the organic tissue in the canal(s)

c. removal of 100% of the microbial contaminants

d. all of the above

PLEASE PHOTOCOPY ANSWER SHEET FOR ADDITIONAL PARTICIPANTS.

AGD Code 074

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ANSWER SHEET

Safety and Efficacy Considerations in Endodontic Irrigation

Name: Title: Specialty:

Address: E-mail:

City: State: ZIP: Country:

Telephone:Home() Office() Lic.RenewalDate:

Requirementsforsuccessfulcompletionofthecourseandtoobtaindentalcontinuingeducationcredits:1)Readtheentirecourse.2)Completeallinformationabove.3)Completeanswersheetsineitherpenorpencil.4)Markonlyoneanswerforeachquestion.5)Ascoreof70%onthistestwillearnyou3CEcredits.6)CompletetheCourseEvaluationbelow.7)MakecheckpayabletoPennWellCorp.For Questions Call 216.398.7822

Educational Objectives1. Listanddescribethechallengesforsuccessfulendodontictreatment

2. Listanddescribethedifferenttypesofrootcanalirrigants,theirrelativeadvantagesanddisadvantages

3. Listanddescriberootcanalirrigationsystems

4. Describeandexplainasodiumhypochloriteincident

5. Listanddescribethestepsthatcanbetakentoavoidasodiumhypochloriteincident

Course EvaluationPleaseevaluatethiscoursebyrespondingtothefollowingstatements,usingascaleofExcellent=5toPoor=0.

1.Weretheindividualcourseobjectivesmet? Objective#1:YesNo Objective#3:YesNoObjective#2:YesNo Objective#4:YesNo

Objective#5:YesNo

2.Towhatextentwerethecourseobjectivesaccomplishedoverall? 5 4 3 2 1 0

3.Pleaserateyourpersonalmasteryofthecourseobjectives. 5 4 3 2 1 0

4.Howwouldyouratetheobjectivesandeducationalmethods? 5 4 3 2 1 0

5.Howdoyouratetheauthor’sgraspofthetopic? 5 4 3 2 1 0

6.Pleaseratetheinstructor’seffectiveness. 5 4 3 2 1 0

7.Wastheoveralladministrationofthecourseeffective? 5 4 3 2 1 0

8.Doyoufeelthatthereferenceswereadequate? Yes No

9.Wouldyouparticipateinasimilarprogramonadifferenttopic? Yes No

10.Ifanyofthecontinuingeducationquestionswereunclearorambiguous,pleaselistthem.___________________________________________________________________

11.Wasthereanysubjectmatteryoufoundconfusing?Pleasedescribe.______________________________________________________________________________________________________________________________________

12.Whatadditionalcontinuingdentaleducationtopicswouldyouliketosee?______________________________________________________________________________________________________________________________________

AUTHOR DISCLAIMERThe author of this course has no commercial ties with the sponsors or the providers of the unrestricted educational grant for this course.

SPONSOR/PROVIDERThis course was made possible through an unrestricted educational grant from Discus Dental. No manufacturer or third party has had any input into the development of course content. All content has been derived from references listed, and or the opinions of clinicians. Please direct all questions pertaining to PennWell or the administration of this course to Machele Galloway, 1421 S. Sheridan Rd., Tulsa, OK 74112 or macheleg@pennwell.com.

COURSE EVALUATION and PARTICIPANT FEEDBACKWe encourage participant feedback pertaining to all courses. Please be sure to complete the survey included with the course. Please e-mail all questions to: macheleg@pennwell.com.

INSTRUCTIONSAll questions should have only one answer. Grading of this examination is done manually. Participants will receive confirmation of passing by receipt of a verification form. Verification forms will be mailed within two weeks after taking an examination.

EDUCATIONAL DISCLAIMERThe opinions of efficacy or perceived value of any products or companies mentioned in this course and expressed herein are those of the author(s) of the course and do not necessarily reflect those of PennWell.

Completing a single continuing education course does not provide enough information to give the participant the feeling that s/he is an expert in the field related to the course topic. It is a combination of many educational courses and clinical experience that allows the participant to develop skills and expertise.

COURSE CREDITS/COSTAll participants scoring at least 70% on the examination will receive a verification form verifying 3 CE credits. The formal continuing education program of this sponsor is accepted by the AGD for Fellowship/Mastership credit. Please contact PennWell for current term of acceptance. Participants are urged to contact their state dental boards for continuing education requirements. PennWell is a California Provider. The California Provider number is 4527. The cost for courses ranges from $49.00 to $110.00.

Many PennWell self-study courses have been approved by the Dental Assisting National Board, Inc. (DANB) and can be used by dental assistants who are DANB Certified to meet DANB’s annual continuing education requirements. To find out if this course or any other PennWell course has been approved by DANB, please contact DANB’s Recertification Department at 1-800-FOR-DANB, ext. 445.

RECORD KEEPINGPennWell maintains records of your successful completion of any exam. Please contact our offices for a copy of your continuing education credits report. This report, which will list all credits earned to date, will be generated and mailed to you within five business days of receipt.

CANCELLATION/REFUND POLICYAny participant who is not 100% satisfied with this course can request a full refund by contacting PennWell in writing.

© 2011 by the Academy of Dental Therapeutics and Stomatology, a division of PennWell

SAFE0111DE

31.32.33.34.35.36.37.38.39.40.41.42.43.44.45.46.47.48.49.50.

www.ineedce.com Customer Service 216.398.7822 15

SPECIAL

IntroduCtory

offEr!

Mention Code:

SP2017

Kills microbes dead.Single-Visit Disinfection is now a Reality Time is valuable for both your patients and your practice. Fortunately, the EndoVac is clinically proven to deliver 100% bacterial kill levels1 with complete safety2 and significantly less post-operative pain3 for your patients. EndoVac delivers dead-on success, the first time around. If the bugs are dead, close the case.

“...the present results demonstrated that reliable disinfection can be achievable with efficient and safer irrigation delivery systems, such as the EndoVac system, and that the use of intracanal antibiotics might not be necessary.”

Cohenca OOOOE 2010 Jan;109:e42-46

Call today to schedule an in-office demo.

(800) 451-8176discusdental.com

Irrigation Protocol. Easy as 1, 2, 3...1. EndoVac Master Delivery Tip

— Gross Debridement & Disinfection Provides a constant flow of irrigant without the risk of overflow. The MDT is used after each instrument change to remove gross debris arising from instrumentation.

2. EndoVac MacroCannula — Debridement & Disinfection Deep in the Canal Removes coarse debris deep inside the canal after all instrumentation is completed.

3. EndoVac MicroCannula — Complete Apical Debridement & Disinfection at Working Length Maximum microbial control using a 0.32 mm cannula and negative pressure to safely draw irrigants to the apical termination and create a vortex-like cleaning of the apical third.

100% Safe.* 100% Kill. 1 Single Visit.

(1) Journal of Endodontics 2008;34:1374-1377(2) Journal of Endodontics 2009;35:545-549(3) Journal of Endodontics 2010;36:1295-1301 * The claim “100% Safe” refers to the finding that the EndoVac MicroCannula and MacroCannula

produced no extrusion of irrigant apically in the study reported in J Endod 2009;35:545-549. The EndoVac is intended only for the irrigation of root canals during endodontic treatment and only for use according to manufacturer’s instructions.© 2010 Discus Dental, LLC. All rights reserved. ADV-3172 120910 20-2653