General Updates

Diagnosing Cracked Teeth. Operation Complex.

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In Australia, the average dentist sees at least one patient with cracked tooth syndrome (CTS) per week (Bader et al 1995), so managing this condition is bread and butter work.  When dealing with CTS a good outcome relies on an accurate diagnosis but this can vary from straightforward diagnostic results to complex, inconsistent signs and symptoms that are difficult to distinguish from other dental and non-dental pathologies.

A detailed pain history is a good place to start. First and foremost, look out for pain on biting. Sensitivity to cold/sweet/hot, and symptoms of reversible/irreversible pulpitis may be reported too. Where there is periodontal involvement due to advanced CTS or vertical root fracture, there may also be recurrent swelling, or a feeling of vague pain or pressure. Patients with a cracked tooth often report having made multiple dental visits, with only temporary pain relief achieved.

I think it’s important to distinguish between what we refer to as CTS, and vertical root fracture. CTS usually occurs in a vital tooth. The pain that is felt is a response of the vital pulp and progression of the condition relates to increasing inflammation of the pulp due to bacterial infiltration of the crack. Vertical root fracture occurs most commonly (but not exclusively) in root filled teeth. The pain that is felt is periodontal in nature and relates to infection of the crack.

When it comes to conducting the examination, we’re looking to confirm first the diagnosis of CTS, and secondly diagnose the pulp. These include, in order of importance:

  • Bite tests to reproduce the chief complaint. By far the best method is to use a ‘Tooth Slooth’ or ‘FracFinder’. Cotton rolls, rubber wheels etc. can be used, but they can’t as accurately isolate pressure to one part of the tooth.

Note: Though pain on release is considered to be a classic sign of a cracked cusp, one study actually found that 68% of cracked tooth cases had pain only when pressure was applied (Abbott & Leow 2009). That said, if you do find that the pain is significantly worse on release than on biting, you can be comfortable with the diagnosis of CTS.

  • Perio probing – presence of a deep, narrow pocket at a single site may indicate a vertical root fracture or endo lesion draining through the periodontium.

In this xray you can see the two molars present with lucencies that surround the coronal portion of the mesial roots. The video below is not the best quality, but you get the drift of how a vertical root fracture presents. A vertical root fracture usually presents as a deep, narrow pocket. Locating a pocket such as this can only be done adequately under local anaesthesia.

Note the lucency surrounding the mesial roots of the first and second molars, yet there is no distinct periapical lucency. This is suggestive or vertical root fracture. The video below shows the periodontal probing pattern.

httpv://youtu.be/8P5trYcaNII

  • Visual examination (with dental operating microscope and rubber dam for best results). Pay particular attention to marginal ridge areas. Restoration removal is ESSENTIAL to visualise the crack completely.
Diagnosis of Cracked Tooth

Removal of the restoration allows the full extent of the crack to be visualised.

  • Staining and/or transillumination – staining the crack with methylene blue + transillumination is a good combination to confirm the presence of a crack. (Wright et al. 2004).
  • Pulp testing – The pulp is usually vital in CTS and non-vital in vertical root fracture, but you need to confirm this, because the status of the pulp will help determine treatment.
  • Palpation, percussion testing, mobility testing as per ususal to confirm pulpal and periapical status.
  • Radiographic examination – may not be useful in actually identifying the crack, but it can help to rule out other options during your differential diagnosis stage. In cases of complete vertical root fracture, you may be able to see periradicular bone loss (a ‘halo’ radiolucency). There is plenty of debate as to whether CBCT can confirm the presence of a crack, and I would be wary of relying on this for diagnosis.

I’ll discuss my preferred method of management of CTS in an upcoming post.

References

Abbott, P,  Leow, N 2009. Predictable management of cracked teeth with reversible pulpitis. Aust Dent J, 54, 306-15.

Bader, JD, Martin, JA,  Shugars, DA 1995. Preliminary estimates of the incidence and consequences of tooth fracture. J Am Dent Assoc, 126, 1650-4.

Wright, HM, Jr., Loushine, RJ, Weller, RN, Kimbrough, WF, Waller, J,  Pashley, DH 2004. Identification of resected root-end dentinal cracks: a comparative study of transillumination and dyes. J Endod, 30, 712-5.

Clinical Tips, General Updates, Study Guides

An Endodontic Masterclass

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This is just a short post to let you know that I will be running a hands-on course for general dentists on October 12 in Brisbane. I wanted to let Endospot followers have the first opportunity to sign up. It should be a great day with a nice mix of useful information, practical advice and hands-on experience.

You can download the course flyer here or sign up here.

I hope to see you there.

Pat Caldwell

Clinical Tips, Endodontic Preparation Techniques, General Updates, Irrigation

The Squid. A Study in Persistence and Access Design

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I know it’s been a long time since I’ve posted so I thought I’d show a case that caused me some trouble recently. The owner of this tooth had suffered a significant facial swelling and ended up in hospital. Fortunately, the swelling had subsided by the time I saw him and he was keen to save the tooth.

Lower Premolar with unusual anatomy

A Wide Canal That Narrows Suddenly is an Indication of a Splitting Canal.

Lower premolar AP 2
Apical Periodontitis is Apparent. Note the Bulbous Shape of The Root.

The thing to note about this pre-op xray are that the canal appears to split at the mid root level. Even if you can’t see the split, the fact that the canal narrows suddenly is an indication of a split in the canal system. The second telling point that we are dealing with something complex is the bulbous shape of the root, when compared to the first premolar. This alone would tell us that we should be looking for anatomy other than a single canal.

I was able to locate two canals, and confirm that these canals joined apically, but I wasn’t happy with the position of the files in the radiograph. As you can see, the lingual canal was quite centred in the root, while the distobuccal canal is shifted to the distal. It doesn’t look right does it? There must be another canal.

Lower Premolar with unusual anatomy showing working length

Note the Off-Centre Location of the Second File

So…. I know to look for a third canal, but no matter how hard I looked, I just couldn’t find it. The canal were prepared and obturated, with the result below.

Initial Obturation Unusual Premolar

After Preparation and Obturation a Small Squirt of Sealer to the Mesial Confirms the Missed Anataomy

So you can see the squirt of sealer to the mesial at the mid-root point. There is no doubt that some anatomy has not been properly cleaned, and would likely be full of infected tissue. Back in we go. The GP was removed and the access expanded to allow location of the canal to be identified and confirmed with a file.

Unusual Anatomy in Premolar

There it is!

The third canal was then prepared. It too joined the other canals apically. The key to cleaning this sort of anatomy is passive ultrasonic irrigation, which I have discussed previously. The only way to then obturate is with a warm technique such as continuous wave or warm vertical. The tooth, of course needs a crown. In this case persistance paid off and the outcome can be much more certain now that the full anatomy has been cleaned and obturated. In hindsight, a cone beam CT scan may have assisted in locating the full anatomy.

Pat

Premolar with unusual anatomy

I Call This Tooth “The Squid”

Unusual Anatomy of Premolar After Obturation

The Arrow Shows the Spot Where the Missing Canal Was Located

General Updates, Irrigation

Photon Induced Photoacoustic Streaming (PIPS)

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Happy New Year from the mountains of Japan where I’m hitting the ski slopes, eating some delicious meals and soaking up some fantastic Japanese hospitality. Last night we were served the traditional midnight meal of Soba Noodles by our hosts at the Sidehill Lodge in Hakuba, Nagano Prefecture.

Budda with Skis in Hakuba

The skiing Budda accross the road from our lodge in Hakuba

I’m a fan of utilizing passive ultrasonic irrigation (PUI) to improve the effectiveness of our irrgants, and believe that it produces root canals with fewer debris and bacteria than needle irrigation alone. Recently there has been some talk about the use of lasers to activate our irrigants in a similar manner and there is at least some evidence that this may improve the cleanliness. Here is a promotional video to give you a brief overview:

httpv://www.youtube.com/watch?v=U0dLJWm6LGk&feature=related

 

Now, we are still waiting on evidence to prove that any of these methods provide a better outcome in terms of healing or prevention of apical periodontitis, but in the meantime, we should be aiming to produce the cleanest canals we can.

My colleague Mateus Miranda has volounteered to look into the use of lasers to activate irrigants and has produced a nice overview of the available evidence. The key paper so far is probably the one by Ove Peters in the JOE in 2011 showing an improved ability of the technology to reduce, but not remove bacteria from intra-orally infected teeth.

Enter Mateus……….

There has been recently introduced onto the dental market a said “revolutionary” mechanism for cleaning and debriding of root canal systems. The PIPS uses Erbium: Yttrium Aluminium Garnet (Er:YAG) laser energy at sub-ablative power levels which produces wavelengths of 2940nm. PIPS was developed by Dr. Enrico DiVito with assistance from Dr. Mark Colonna.

This non-visible-to-human-eye laser energy is strongly absorbed by water and when activated with specific peak power derived from short pulse duration results in a photomechanical phenomenon or photo-ablation on dentin, allegedly removing smear layer and exposing dentinal tubules.

The Er: YAG laser was tested for the first time in 1988 for preparing dental hard tissues. It was successfully used to prepare holes in enamel and dentine with low ‘fluences’ (energy (mJ)/unit area (cm2)). In 1989, it was demonstrated that the Er: YAG laser produced cavities in enamel and dentine without major adverse side effects (A. HUSEIN 2006).

In 1998 a study performed by TAKEDA FH and colleagues concluded “The root canal walls irradiated by Er:YAG laser were free of debris, with an evaporated smear layer and open dentinal tubules. These results suggested that Er:YAG laser irradiation had an efficient cleaning effect on the prepared root canal walls. FLAVIO SOARES et al (2008) found laser cleanliness in root walls of primary teeth was similar with rotary instruments and superior to manual instrumentation and it required less time for completion. KYOKO INAMOTO et al in 2009 found no smear layer presence following instrumentation of root canal walls using the same laser therapy.

Irrigation wise, ROELAND JG De MOOR et al (2010) showed the efficacy of Laser Activated irrigation (LAI) using Er:YAG for 20 seconds compared to Passive Ultrassonic Irrigation (PUI) for 60 seconds for dentinal debris removal. DIVITO et al (2010) concluded the Er:YAG laser used in this study showed significantly better smear layer removal than traditional syringe irrigation.

Considering thermal effect, studies were performed and were conclusive on the safety of the Er: YAG lasers usage unless proper water cooling and specific power output setting was used (V ARMENGOL et al. 2000, REMI YAMAZAKI et al. 2001, KIMURA et al. 2002, B N CAVALCANTI et al.2003).

Most importantly some studies tested the efficacy of the bactericidal effect of the Er: YAG laser, particularly on Escherichia coli and Enterococcus faecalis and were happy to concluded positively (MORITZ A. 1999, Loma Linda University School of Dentistry.2010). However, a study conducted by OVE A PETERS et al (2011) showed activated disinfection did not completely remove oral bacteria from the apical root canal third and infected dentinal tubules, requiring some further investigation.

But how does PIPS® actually work?
After gaining access to the canal, an instrumentation of the canal is done to ISO #20 only. No further enlargement is necessary thus preserving tooth strength.
This is followed by PIPS® activation delivered from a cone-shaped fiber tip attached to a handpiece within an irrigating solution, either EDTA or NaOCl. The tip is inserted into the coronal third of the canal thus there is no risk of tip breakage from curved canals or undesirable apical extrusion of chemical irrigants possible with other laser endodontic methods (ROY GEORGE et al, 2008). The canal system is finally flushed clean with water and is ready to be obturated.

It is worthy it to check on the images provided by Dr Enrico DiVito and its team related to this new mechanism of root canal debridement. Please follow the link.

To sum up, this new technology seems to be very effective and efficient regarding root canal therapy. The ability to prepare/ instrument canals in a short period of time associated with great reduction of bacterial count (when compared to conventional root canal instrumentation) is absolutely promising.

References:

A. Husein. 2006. Applications of Lasers in Dentistry: A Review.

Takeda FH, Harashima T, Eto JN, Kimura Y, Matsumoto K. 1998. Effect of Er: YAG laser treatment on the root canal walls of human teeth: an SEM study.

Flavio Soares, Claudio H. Varella, Roberta Pileggi, Abi Adewumi, Marcio Guelmann. 2008. Impact of Er,Cr:YSGG Laser Therapy on the Cleanliness of the Root Canal Walls of Primary Teeth.

Kyoko Inamoto, Naoki Horiba, Shinpei Senda, Munetaka Naitoh, Eiichiro Ariji, Akira Senda, Hiroshi Nakamura. 2009. Possibility of root canal preparation by Er: YAG laser.

Roeland J.G. De Moor, Maarten Meire, Kawe Goharkhay, Andreas Moritz, Jacques Vanobbergen. 2010. Efficacy of Ultrasonic versus Laser-activated Irrigation to Remove Artificially Placed Dentin Debris Plugs.

E. DiVito, O. A. Peters, G. Olivi. 2010. Effectiveness of the Erbium:YAG laser and new design radial and stripped tips in removing the smear layer after root canal instrumentation.

V. Armengol, A. Jean, D. Marion. 2000. Temperature Rise During Er: YAG and Nd:YAP Laser Ablation of Dentin.

Reimi Yamazaki, Claudia Goya, Da-Guang Yu, Yuichi Kimura, Koukichi Matsumoto. 2001. Effects of Erbium, Chromium:YSGG Laser Irradiation on Root Canal Walls: A Scanning Electron Microscopic and Thermographic Study.

Yuichi Kimura, Kazuo Yonaga, Keiko Yokoyama, Jun-ichiro Kinoshita, Yoshiko Ogata, Koukichi Matsumoto. 2002. Root Surface Temperature Increase during Er: YAG Laser Irradiation of Root Canals.

Bruno Neves Cavalcanti, José Luiz Lage-Marques, Sigmar Mello Rode. 2003. Pulpal temperature increases with Er:YAG laser and high-speed handpieces.

Moritz A, Schoop U, Goharkhay K, Jakolitsch S, Kluger W, Wernisch J, Sperr W. 1999. The bactericidal effect of Nd:YAG, Ho:YAG, and Er:YAG laser irradiation in the root canal: an in vitro comparison.

Loma Linda University School of Dentistry. 2010. Final Report: Efficacy of Er: YAG Laser on Root Canals Infected with Enterococcus faecalis.

Ove A. Peters, Sean Bardsley, Jennifer Fong, Goldie Pandher, Enrico DiVito. 2011. Disinfection of Root Canals with Photon-initiated Photoacoustic Streaming.

Roy George, Laurence J. Walsh. 2008. Apical Extrusion of Root Canal Irrigants When Using Er: YAG and Er,Cr:YSGG Lasers with Optical Fibers: An In Vitro Dye Study.
Hyperlink: http://www.fotona.com/media/aurora/dokumenti/2010/11/pips_brochure_fotona_web.pdf

 

 

 

 

 

General Updates

Invasive Cervical Resorption. Coming Soon to a Tooth Near You.

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Invasive Cervical Resorption

Invasive Cervical Resorption can spell disaster for a tooth if not diagnosed early.

The disease process known as Invasive Cervical Resorption (ICR) can be quite devastating for a tooth. The big problem for us as practitioners is that it’s difficult to identify ICR early. By far the most comprehensive article on ICR is by Geoff Hiethersay, (an Australian Endodontic legend) and this is the one article you need to read if you want more information than is contained in this post (Hiethersay 2004).

For dental resorption to occur, we need three things: 1. blood supply; 2. a stimulus; 3. breakdown or loss of the protective layer. When I refer to the protective layer, what I’m referring to is the pre-cementum externally, and the pre-dentine internally. It might seem odd that these seemingly frail tissues are able to protect tooth structure. The reason this protection occurs is that specific peptides named RGD peptides provide binding sites for the resorptive cells. These RGD peptides are bound to calcium salt crystals on mineralised surfaces. So when the resorbing cells reach the unmineralised pre-dentine or pre-cementum, they are unable to bind as no RGD peptides are present and thus, no resorption occurs.

So, it would seem that a lack of pre-cementum on the surface of a root may predispose to the development of ICR. This could happen due to trauma via a number of mechanisms such as scaling/root planing, internal bleaching, physical trauma or perhaps orthodontic movement of teeth. Dental trauma, internal bleaching and orthodontics have been associated with the development of ICR (Heithersay 1990). The condition also occurs without any pre-disposing factors, and it is suggested that a genetic lack of cementum (and therefore pre-cementum) may be present in those cases.

Invasive Cervical Resorption CBCT

This is the same tooth as seen in the xray above. Invasive cervical resorption is both external and cervical in nature.

ICR is known by a number of other names and one of these is External Invasive Cervical Resorption. The “External” label is a reasonable addition as ICR is always external in nature. The resorption develops from cells in the periodontal ligament in the cervical region. This is the area that is most likely to have an absence of cementum from a developmental point of view at least. I mentioned that pre-dentine is also protective against ICR. The reason we know this is that in extensive cases the external resorption reaches the pulp, but the pulp is spared, protected by the pre-dentine. For this reason, even in extensive cases of ICR, the pulp usually remains vital. The resorptive tissue which invades the tooth seems to resist bacterial invasion. Certainly, you will not usually find a traditional periodontal pocket adjacent to the resorption.

I mentioned the three things that are required for resorption to occur. It’s obvious we have a blood supply and lack of protection, but where does the stimulus come from? The answer is that we don’t know. It has been hypothesised to be either inflammatory due to sulcular infection or a benign proliferative fibrovascular or fibro-ossesous disorder. That’s quite a mouth-full and I’ll leave it up to somebody much smarter than me to work out which one is correct. The cell that does the resorbing is similar in morphology to the osteoclast and may represent a functional variant of the same lineage.

Invasive Cervical Resorption Pink Spot

A slight pink discolouration (arrow) is the only symptom from this tooth, which tested positive to pulp testing. This tooth is the same as seen in the xray and CBCT above.

Clincially, the tooth is usually completely asymptomatic. There may be a pink (or sometimes grey) discolouration of the crown but often the radiograph is the only indication that resorption is occuring. Radiographically, a mottled lucency is present and in advanced cases, there is a radiopaque line bordering the pulp chamber. Taking mesial and distal angled images will see the lesion move in relation to the pulp and this will differentiate the resorption from an internal resorption, as well as tell you if it’s positioned buccaly or lingually. Of course cone beam CT will also provide useful information.

Heithersay’s clinical classification is as follows:

Class 1 – small lesion with shallow penetration

Class 2 – well defined lesion close to coronal pulp

Class 3 – Deeper invasion to include the coronal third of radicular dentine

Class 4 – Large invasive lesion extending beyond the coronal third of the root

Class 1 and 2 lesions can be treated predictably, but the success rate in treating class 3 and 4 lesions drops dramatically. Treatment usually consist of using trichloracetic acid (TCA) to attempt to destroy the resorptive tissue via coagulation necrosis. The difficulty comes from the fact that the resorption is not usually confined to a discrete area and can have multiple feeding channels from well below the gingival margin. The lesion can also be treated surgically, but in practice it can be difficult to access and may even require bone removal to gain direct vision of the lesion. This rapidly gets destructive of both tooth structure and periodontal tissues which is why it is important to identify and treat (if indicated) the disease as early as possible. See Heithersay’s article for a description of the use of TCA and also other treatment options.

References:

Hiethersay G. Invasive Cervical Resorption. Endodontic Topics 2004, 7, 73–92

Heithersay G. Invasive cervical resorption: an analysis of potential predisposing factors. Quitessence Int 1999: 30: 83-95
Dental Trauma, General Updates

Endospot Sites of Note: Dental Trauma Guide

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Jens Andreasen and his team have compiled all their knowledge at created the Dental Trauma Guide. If you haven’t seen this before, go and have a look. It’s easy to use and might just help you out in an emergency dental trauma situation.

The site also includes all the references for those of you who need them.

I recommend you bookmark it at: http://www.dentaltraumaguide.org/

C-shaped Canals
Clinical Tips, Endodontic Preparation Techniques, General Updates

Endospot Cases of Note. Case 1. C-Shaped Canal.

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Welcome to the first Endospot Case of Note. This case is of a C-Shaped lower molar and I’ve tried my best to highlight the interesting aspects of the case, explain what can be seen using our diagnostic tools, and also how to treat these cases. As usual, I would love to hear your thoughts and you can leave a comment below.

If you want to review the anatomical variations of C-shaped canals, I recommending reading the following references:

Fan B, Cheung GS, Fan M, Gutmann JL, Bian Z (2004). C-shaped canal system in mandibular second molars: Part 1 Anatomical features. Journal of Endodontics 30(899-903.
Fan B, Cheung GS, Gutmann JL, Fan W (2004). C-shaped canal system in mandibular second molars: Part II Radiographic features. Journal of Endodontics 30(904-8.

This video can be watched in HD on Youtube. Please enjoy!

httpv://www.youtube.com/watch?v=dF3JUsY_k8I

The SAF Pump
Endodontic Preparation Techniques, General Updates, Irrigation

First Impressions of the Self Adjusting File

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I had the opportunity during the Australian Dental Association Congress to get my hands on the new Self Adjusting File. It’s not yet available for purchase in Australia, but will be in a couple of months. The SAF comes in 21, 25, 31mm lengths and two widths.

The Self Adjusting File

The three lengths of the Self Adjusting File

To be honest, there is a lot of cynicism out there amongst Endodontists regarding this instrument, mainly because of the manufacturer’s claim that you only require one SAF file to prepare the canal. I think some of the cynicism is driven by the fact that both Dentsply and VDW have recently released their own single file reciprocating systems. The cynicism of Endodontists regarding single file systems is warranted in my opinion. Realistically no one single round file is going to be adequately able to clean and shape the complex anatomy that we are faced with in root canals. They may also force the heavily infected contents of the coronal part of the canals apically and they may not give sufficient time and bulk of irrigant to allow cleansing. When you read the fine print. even the manufacturers will admit that certain canals with particular anatomy preclude the use of the reciprocating files.

In the case of the SAF, the manufacturer told me that they were not selling the system as something that will make preparation easier, cheaper or faster, but rather increase the quality of the preparation. This is probably a good line to take if you want acceptance by the Endodontic community.

OK, on to the SAF. Basically, the file is made of a NiTi mesh with a coating that is designed to “sandpaper” the walls of the canal. The mesh compresses to fit the shape of the canal. I admit I thought the engineering concept behind the file was pretty cool. The manufacturer told me that the designer was involved in the production of cardiac stents and utilised the basic design concept of these. I made the short video below to give you an idea of how the file behaves.

httpv://www.youtube.com/watch?v=UGZZP6_vtN0

On using the file, my first impression is that I’m not going to be out of a job as an Endodontist due to the release of the SAF. You still need to find the canals and prepare to a size 20 at the apex before using it. If you don’t prepare a path, then you’ll end up blocking the canal with debris, just like can be done with rotary files. That said, the ability of the file to prepare these irregular plastic shaped blocks was impressive. The block has an oval shaped canal with fins in it and a fine red coating on the inside. In a one minute session, the file pretty much cleaned all the red stuff off the inside.

I took one of these blocks back to my surgery to see how well I could clean it using traditional methods and after about four minutes of using rotary Ni Ti, hand files, and ultrasonic files, I still couldn’t get the block as clean as I did with the SAF. I’m not sure how well the apical part of the preparation was phycially cleaned by the SAF. If I was using the SAF, I think I’d probably end up gauging the apical portion after using SAF and maybe finishing off with rotary files to enlarge it if required.

Self Adjusting File Compared to Rotary

Plastic block prepared by rotary NiTi on the right and SAF on the left. I took this image from the manufacturer's online powerpoint presentation, but it mirrors the experience I had.

There are two aspects to the SAF system. The first is the ability of the file to clean, and the second is the fact that it is constantly pumping fresh NaOCl through the centre of the file. It may well be that this is the most useful/best aspect of the system. Often in our literature and certainly by manufacturers an improperly greater emphasis is placed on the mechanical preparation of root canals systems compared to our efforts to actually clean the canals of tissue and microorganisms. In a previous post I’ve mentioned the benefits of passive ultrasonic irrigation, and I think the continual deposition of fresh NaOCl into the canal during preparation has great potential.

There isn’t really much research available on the SAF. I could find seven papers in pubmed, all bench top studies (see the end of this post for a complete list). The general outcome of these is that the SAF does a reasonably good job of debriding most areas of the canals under the conditions of the studies, and some nice microCT images were produced. One study (remember these are in vitro, not in actual clinical situations) found the SAF was significantly better at disinfecting canals infected with e. faecalis than rotary NiTi (Siquiera Jr et al. 2010). I guess we need to see more research and time will tell if the SAF is able to disinfect canals better than what we currently have available. My feeling is that it’s a possibility.

httpv://www.youtube.com/watch?v=bWhd8Mgbtmw&NR=1

Above is the manufacturer’s description of the irrigation function of the SAF

The irrigation part of the SAF system is also the biggest downside. In order to use it as described, you have to buy the electronic pump that goes with it. The pump has a timer to make sure you use the file for the full minute, so I guess that’s a good thing. However, I believe that the pump will be susceptible to failure as you manage to spill the NaOCl over it as you repeatedly fill the reservoir. The manufacturer admitted this fact and impressed that the correct funnel needed to be used.

The pump is also another contraption that we have to plug in and put on our benchtops (along with our endo motor, ultrasonic unit, pulp tester, apex locator, system B, obtura etc etc), not to mention another foot pedal on the floor. To be honest, having to buy the pump might stop me from buying the whole unit. We did question the manufacturer on whether we could just use a a syringe filled with NaOCl attached to the tubing which connects to the file, and although he obviously wants us to buy the pump, I think the answer is yes. This would be a much neater and more acceptable to me than having the pump on the bench.

The SAF Pump

The SAF pump. Another machine to clog up our benchtops.

One of the big concerns with rotary NiTi files is obviously the issue of fracture. My friends and I tried very hard to break the SAF and were successful. It did take a while though, and to it’s credit, when the file broke, it was just one of the arms that breaks, leaving the whole file retrievable. I do stand to be proven wrong, but I think that it would be quite unlikely that a separate portion of the file would break and lodge in a canal requiring removal.

SAAF breakage

Mode of failure of the SAF. This image was taken from manufacturer's powerpoint presentation, but is exactly what I saw during the trial.

The business end of all these things are how much they cost. If you buy in bulk, the cost of one of these files in Australia is going to be about AU$70. That’s about US$73 at today’s rates. So, they are quite expensive, especially if you plan to use additional rotary files to further prepare the apical area, you break one before you finish the tooth or you need to use both the larger and smaller width files to complete multiple canals in one tooth. You also need to buy a special handpiece or handpiece head, plus the irrigation system if you go by the manufacturer’s instructions. This might scare a few people away and into the arms of the single file reciprocating systems. I’ve previously stated that the reciprocating files may become a part of our armamentarium for particular cases, and it may be that the SAF fits into this category.

My overall impression of the SAF, despite being cynical to begin with was a positive one and I think that this system has potential to do more for us than the reciprocating files. Stephen Cohen, author of Pathways of the Pulp will be in Australia in June running workshops on the system, so we’ll get another look at it then. The SAF is certainly no panacea for endodontically infected teeth, and preparing canals that are already opened to a size 20 file is actually the easiest part of an Endodontist’s day. That said, if further evidence comes through indicating that the SAF system does in fact kill more bacteria in the root canal than our current systems, then I guess we’ll all want one.

Pat Caldwell

References: Hof R, Perevalov V, Eltanani M, Zary R, Metzger Z. The self-adjusting file (SAF). Part 2: mechanical analysis. J Endod. 2010 Apr;36(4):691-6.

Metzger Z, Teperovich E, Cohen R, Zary R, Paqué F, Hülsmann M. The self-adjusting file (SAF). Part 3: removal of debris and smear layer-A scanning electron microscope study. J Endod. 2010 Apr;36(4):697-702.

Metzger Z, Teperovich E, Zary R, Cohen R, Hof R. The self-adjusting file (SAF). Part 1: respecting the root canal anatomy–a new concept of endodontic files and its implementation. J Endod. 2010 Apr;36(4):679-90.

Paqué F, Peters OA. Micro-computed Tomography Evaluation of the Preparation of Long Oval Root Canals in Mandibular Molars with the Self-adjusting File. J Endod. 2011 Apr;37(4):517-21.

Peters OA, Boessler C, Paqué F. Root canal preparation with a novel nickel-titanium instrument evaluated with micro-computed tomography: canal surface preparation over time. J Endod. 2010 Jun;36(6):1068-72. Epub 2010 Apr 10.

Peters OA, Paqué F. Root canal preparation of maxillary molars with the self-adjusting file: a micro-computed tomography study. J Endod. 2011 Jan;37(1):53-7. Epub 2010 Oct 8.

Siqueira JF Jr, Alves FR, Almeida BM, de Oliveira JC, Rôças IN. Ability of chemomechanical preparation with either rotary instruments or self-adjusting file to disinfect oval-shaped root canals. J Endod. 2010 Nov;36(11):1860-5. Epub 2010 Sep 16.

Professor Marco Versiani
General Updates

Introducing The Root Canal Anatomy Project

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Professor Marco Versiani

Professor Marco Versiani

Over in Sao Paolo, Brazil, Professor Marco Versiani and his team have been busy scanning teeth with MicroCT. MicroCt is a an exciting tool for the examination of tooth anatomy, and is particularly useful for looking at root canal anatomy. The result of Prof. Versiani’s work is the Root Canal Anatomy Project. They’ve put together a website where you can go and have a look at the results of their work. It’s a great source of information and provides nice 3D views of pulp anatomy. Best of all, it’s free and Prof. Versiani will allow you to use the content for education purposes. Below is a sample of the work, and below that is the terms of the free use of the content:

httpv://www.youtube.com/watch?v=5fM95Uo_Sts&feature=player_embedded

The images and videos of “The Root Canal Anatomy Project” blog were developed at the Laboratory of Endodontics of Ribeirao Preto Dental School – University of Sao Paulo – and may be freely used for attributed noncommercial educational purposes by educators, scholars, student and clinicians. It means that all material used should include proper attribution and citation (http://rootcanalanatomy.blogspot.com/). In such cases, this information should be linked to the image in a manner compatible with such instructional objectives.