Knowing when to treat and when to refer

I believe that general dentists should do as much endodontic treatment as is within their capability and comfort level. This judgement should be based on an honest assessment of their skills, experience, equipment and time available.

Integrating endodontics into general practice is multi-factorial and complex. For example, is the obturation to be done with a warm carrier-based product or via a technique like SystemB with bonded obturation delivered with an instrument such as the Elements Obturation unit (SybronEndo, Orange, CA, USA)? Will the visualisation be afforded by loupes, the naked eye or the surgical operating microscope (SOM)? Will irrigation take place with sodium hypochlorite only or chlorhexidine or a combination of the two or other irrigants? What kind of teeth will be referred, will re-treatment be attempted? The list of questions to be answered could go on and on.

In the opinion of the author, the greatest problem in creating excellence in endodontic treatment is not that the clinician does not have the skills but rather a combination of three challenges that frequently emerge. These are: 1) having enough time to do an excellent job; 2) treatment planning, i.e. knowing what teeth can be treated, should be treated and which should be referred and 3); integrating new materials and techniques so that they can be applied to their greatest benefit.

There is an old expression that it is the rider, not the bike, that makes the difference in a competitive race and the same could be said of endodontics. A talented clinician can produce excellent results almost irrespective of the materials used. That said, there is a huge difference in how user friendly the chosen system is, learning curve, potential morbidity and predictable effectiveness between various techniques. Choosing which philosophies can and should be followed is challenging.

Many clinicians have decided to use materials and techniques because their friends have recommended them. While this might work some of the time, it is not the most effective method for choosing how to decide which technologies to bring into the clinical realm of the given office or clinician.

First, it is a bias of mine that clinicians should learn how to become more efficient doing endodontics on extracted teeth and not on live patients. This said, I have seen many cases referred to me where the clinician is using a new device or file and problems arise and referral becomes necessary.

This is preventable. Simply put, attaining a technical proficiency demands a focused practice so that the actions required become reflexive on the part of the clinician. For example, if the clinician is instrumenting a root canal system with rotary nickel titanium (RNT) files, it is essential to irrigate copiously and recapitulate frequently. To not do so is to invite iatrogenic outcomes. An automatic reflex of RNT insertion, irrigation, recapitulation and a subsequent insertion is vital to keep the canal path clear. Such a practice requires that the clinician first knows that this is desirable and then commit to do so in a manner that is repetitive and done by reflex almost without thinking.

Secondly, it is axiomatic that treating only the teeth that are within the capabilities of the doctor should be attempted. Scuba divers would or should never knowingly go on dives that are beyond their level of capability. Doing so could be fatal. While not quite the same potential outcome, getting into deep water in the middle of a root canal can easily be the harbinger of a tooth that cannot be repaired or restored. This knowledge and risk factor appreciation is a key diagnostic skill if one is to attempt and or perform root canal treatment.

The appreciation of what can and should be attempted is a function of radiographic interpretation and diagnostic skills to be certain that: 1) the problem is odontogenic – doing a root canal will in fact heal the patient; 2) that the suspected tooth is the offender; and 3) that the technical challenges that the tooth represents have been appreciated.

A small textbook could be written, but the longer or shorter the roots, the more curved and calcified, and the greater the degree of technical difficulty. Root canals are much like the English professional football leagues in one sense – some are Premiership and some belong in the Conference, but the closer one gets to the top level the harder the clinical management of the case. Knowing when to treat and when to refer is an art, not a science.

Coincident to the technical level of difficulty that the tooth may present, there is a corresponding determination of the patient’s level of cooperation. Some patients who might have very simple teeth which need root canal treatment may actually have a very challenging case based on their inability to open, hold still, get numb, etc.

In colloquial terms, a Conference level tooth can easily become Champions League on a patient who cannot or will not cooperate. My rule of thumb in such situations is what I call the ‘mum test’. If the patient were my mother, would I be the best person to treat them? If the answer is yes, the chances for success rise; the converse is true as well.

An informed patient is usually a relaxed one. The patient, at a minimum, should have the procedure alternatives and risks explained to them as well as have their questions answered. It is also important that if the clinical case will require any treatment beyond the root canal that the patient is made aware of this. For example, a new crown, crown lengthening, tissue grafts, etc. No surprises is ideal mantra of the dentist with regard to consent.

Successful outcomes are a direct result of a planned and focused procedure that accentuates the achievement of excellent steps that build upon one another. Use of a rubber dam, a patient wearing safety glasses, excellent anaesthesia, are such steps.

Additional steps the clinician should decide upon are:

1) Am I going to use RNT instruments?

2) Is obturation going to be warm or cold? Carrier based or master cone generated?

3) Am I going to place a coronal restoration at the time of treatment?

4) Am I going to visualise my treatment with a surgical microscope?

5) Am I going to utilise digital radiography?

While a list of these questions could go on indefinitely, these represent a sampling of some of the most clinically relevant questions. Each of these is immense in terms of the variety of potential answers. The answers are the empirical opinions and recommendations of the author based on many years of FT endodontic speciality practice.

First off, RNT instruments can be used safely, efficiently and in an economical manner. To hand file in 2006 or 2007 is to neglect one of the most significant advances in endodontics ever. I am an advocate of the K3 system (SybronEndo, Orange, CA, USA) for its tactile sense, flexibility, cutting efficacy, fracture resistance and universal application across a wide variety of clinical anatomy.

RNT instruments are generally preceded by hand instrumentation and followed (as mentioned) by copious irrigation and recapitulation. K3 is most effectively used from larger tapers to smaller and from larger tip sizes to smaller. This sequence is inherently crown down in that the more coronal portions of the canal are instrumented first and the apical portions are handled last.

Secondly, obturation is most ideally performed warm and bonded. Warm filling techniques allow a heat-softened mass of material to fill all of the various anatomies in the canal system that has ideally been cleared via irrigating solutions. Cold techniques do not provide a way to predictably place an obturating material into all of these eccentricities of the root canal system.

I am not an advocate of warm carrier based systems at this time because they 1) cannot place a bonded material in the canal, 2) are expensive, 3) can be challenging to retreat and, 4) are consistent with greater levels of extrusion of sealer and filling material from a patent apical foramen. Use of a technique like SystemB does not possess these issues. By contrast, the technique is simple, inexpensive, predictable and possesses no challenges with regard to re-treatment.

As mentioned above, obturation with SystemB is made easiest and most efficient with the use of the Elements Obturation Unit which has both a heat source and an extruder to place a heated stream of the material for bulk canal obturation usually in back fill procedures. For a detailed discussion of both bonded obturation and SystemB techniques, the reader is directed to the July 2004 Oral Health Journal from Canada, available online.

Third, placement of an excellent coronal seal at the time of treatment is consistent in the endodontic literature with enhanced healing. The converse is true. Root canals fail for three primary reasons: 1) uncleaned and unfilled space is left in the root canal system; 2) vertical root fracture and 3) coronal microleakage. It is a common event in most speciality practices to retreat failed root canals that have been subjected to coronal microleakage. Such microleakage might be present due to a leaking crown, recurrent decay or quite often a cotton pellet has been left in the chamber.

What is so unfortunate is that this avenue of failure is completely preventable if the coronal build up is placed under the rubber dam at the time of treatment.

Fourth, the use of enhanced visualisation from a source such as the surgical operating microscope is ideal. The author uses the Global microscope (Global Surgical, St. Louis, MO, USA). While there are other acceptable forms of lighting and magnification (high powered loupes with an external source light), use of the SOM will provide the most targeted light and enhancement of the visual field possible. It should be remembered that loupes at the highest magnification are still at the low end of the capabilities of the SOM.

Objections to using the SOM are usually based on system costs. Although, the cost of not having a SOM and trying to do endodontics must be weighed. Without a SOM, canals will be missed more often, more perforations created, etc. It is the opinion of the author that to not use the SOM is actually far more expensive over the long term with regard to lost productivity.

Finally, digital radiography has significant advantages to offer the clinician. The ability to take multiple angles of the radiograph and have instant viewing and software manipulation of these images is a revelation to those who do not presently have the technology.

Simply put, the advantages again given the initial cost in computers and software is ultimately inconsequential to the alternatives in lost time and production. While there are many alternatives in digital radiography choices, the author is an advocate of the DEXIS digital radiography system (DEXIS, Alpharetta, GA, USA) for its excellent image quality, software tools and ease of use. Digital radiography has a number of very practical applications that may not be immediately apparent.

For example, one key advantage during endodontic treatment is the ability to take multiple cone fit images rapidly to verify the true working length as well as image mentally what the final obturation will look like before it happens. An excellent cone fit image can give a very strong indication of the final obturation quality. If the cone is to length, straight and without kinking and has tug back, the final result is virtually assured.

A number of strategies have been developed to help clinicians introduce endodontics into their practices. Key amongst these strategies is knowing when to refer and how to treatment plan cases to determine the difficulties and risk factors that are present before the case is started. Used correctly, bringing the best possible technology into clinical practice has significant value towards creating enjoyable, predictable and profitable endodontics.

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