Creating endodontic excellence: seeing what is really there

Among many other talents, great football players have two in abundance. One is never looking rushed on the ball. They always seem to have enough time to make the pass, run or movement needed with a minimum of wasted effort. In addition, these players have an uncanny knack of seeming to know where the ball is going to go next, which contributes to their rarely being out of position.

It has been said that football is a mental game and that players who are always thinking before, during and after matches about what will and has confronted them, will only get better and create excellent results. Practicing endodontics at the highest level is not unlike this phenomenon.

Seeing what is present before initiating treatment, assessing the risks, planning evasive action, mentally rehearsing the procedure, anticipating what will happen next, visualising the final result and gaining experience from the issues that went well and those that didn’t are the hallmarks of an astute clinician, not unlike those legendary footballers that seem to get better with age.

The case illustrated (Figure 1), which on the surface might have appeared simple, was anything but. A comprehensive discussion of the treatment planning that went into the case by me, as the treating endodontist, is detailed below. Firstly, I believe that great results are most often ordained well before the procedure begins. Before treatment, the clinician has either correctly assessed the patient, tooth, and their own skills and equipment, or not.

If the pre-operative assessment of these issues is accurate, the procedure has a good chance of being optimal. The converse is also true. If we choose the right patient to work with (i.e. we are personally compatible with the given individual and establish trust and rapport), the right tooth given our experience and equipment, and we carry the procedure out correctly, we create the best possible chance for success.

When things go wrong, they do so because we have (amongst other factors):

• Bad planning or no planning

• The wrong equipment

• No training

• Poor case selection (the tooth is not restorable, sound periodontally or of strategic value to retain)

• Not enough time

• Not established rapport or obtained consent

• Misconceptions about the desired outcome of the clinical treatment, as shown by the actual service provided.

Recognising the limitations above, before starting treatment, can go a long way toward their resolution. Unfortunately, such thoughtful deliberation did not precede the case described here before access.

This patient was a 35-year-old female who’d had one visit with her general dentist for initiation of treatment on the lower left first molar. The medical history was non-contributory. The patient reported that the dentist had been placing a filling the day before and had abruptly told her that she needed a root canal. The commenced treatment was left at the stage pictured in Figure 1.

The patient claimed that there was no pre-operative consent and that she did not know what a root canal was, or to what stage her present treatment had been completed. She did not know why she had been referred to me other than that she was supposed to get the root canal finished.

She claimed to have had no indication that a root canal was possible before the filling was initiated. The patient was not easy to communicate with as she frequently interrupted me and, ironically, questioned me continuously about every aspect of her previous treatment and any possible further treatment. Trust had certainly broken down between the patient and her general dentist and I was not able to establish a positive working relationship with her.

Clinically, the patient had mild spontaneous pain prior to her general dental visit and was asymptomatic on the day of my examination with her. The tooth was mildly sensitive to percussion, within normal limits to palpation, slightly mobile, and there was a 6 mm probing in the buccal furca.

A temporary filling was present and the tooth had obturation material in the two mesial canals with the MB canal filled to a level approximately 3-4 mm below the orifice of the canal. The tooth had three obvious roots radiographically (the patient was unaware of this). It is unknown if the general practitioner had realised there were three roots.

The previous obturation material was in the third root which for our purposes we will call the DB root. There was no material in the DL root. Furcal bone loss was present radiographically. In addition, the MB partially filled canal had a very small white spot at the end of its short obturation. There was a large alloy present which encompassed a significant portion of the coronal tooth structure.

The note from the referring doctor said only that the tooth had three canals filled to a .04 tapered 20-tip size preparation and asked me to finish the root canal. The obturation material used was gutta percha.

There were three main issues to address:

1) Was this a patient that I could communicate with and achieve adequate consent from, so as to develop an environment of trust and complete the tooth well?

2) Was the tooth restorable?

3) Could all the technical issues involved in treating the tooth be performed to a high enough standard so as to give the patient an excellent prognosis?

Given the options, the patient chose to extract the tooth. Had the patient accepted the risks and desired treatment, I would have declined to treat the patient given the limitations present and our lack of rapport.

Firstly, with the amount of tooth structure missing coronally and the furcal bone loss, my experience led me to believe that this tooth had a very high likelihood of fracturing in the long term, especially along the furcal floor. It is possible that it might have been of benefit to use a bonded obturation material such as RealSeal (SybronEndo, 01733 371565) in addition to a bonded material such as Core Paste (Den Mat) to minimise root or furcal floor fracture.

In light of the other variables at play, this was not enough to tip my decision toward saving the tooth. RealSeal bonded obturation does give roots greater resistance to vertical fracture (reference available upon request).

Secondly, the MB canal filled to 3-4 mm from the orifice was very close to the furca. Removal of the previous gutta percha and shaping of this canal carried with it an enhanced risk of furcal perforation, especially if the small piece at the apical extent of the filling was a possible fragment of a rotary nickel titanium file that needed removal.

Such a small fragment of separated instrument could explain why the canal was not filled to the terminus, i.e. a blockage had been created that could not be bypassed. Although unlikely, there could have been an undiagnosed pre-existing perforation at the distal aspect of the mesial root.

Finally, the patient was also going to need periodontal treatment for the furcation involvement and it was very clear from our conversation that this patient was not a compliant individual and would not seek care for this periodontal defect.

As an aside, it is also noteworthy that the referring doctor chose to treat these roots to a .04-tapered 20 tip size. Suffice to say that for this particular root canal system, this was too small. The roots were large enough for a proper three dimensional cleansing and shaping, and it is likely that these canals should have been tapered to at least a .06 taper and a 35-60 master apical file size, dependent on the initial diameter of the minor constriction of the apical foramen once gauged.

To visualise the shortcoming in a different way, imagine the amount of irrigant that might or could have actually reached the apical third during the obturation of the canals. It is difficult to imagine that much, if any, irrigant could have reached the apical third to digest the canal contents at that level. In short, the present cleansing and shaping was not large enough to achieve the biologic objectives of root canal therapy.

As a result of the lack of taper and tip size to the preparation as well as the uncleaned and unfilled space in the MB canal, if the tooth was to have been saved it first needed retreatment of the completed portion before addressing the untreated root canal space. Simply trying to locate and instrument the untreated root would have left significant uncleaned and unfilled space within the root canal system that had previously be taken to a .04 taper and 20 tip size preparation.

It is important to evaluate such clinical cases carefully before starting, so as to avoid future disappointment for both the patient and doctor. Had this tooth been re-treated and a crown placed, the long-term prognosis was poor to very guarded. Extraction avoided an unpredictable outcome.

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