Monday, September 26, 2011

Avoiding Root Canal Therapy with MTA

Dr. Hale's excellent post on pulp canal obliteration inspired me to share these few cases where a coronal barrier was also used to avoid root canal therapy. The most recognized reason to avoid complete pulpal debridement is biological, to maintain pulpal vitality, and thus continue root formation, subsequently improving fracture resistance, but there also exist technical limitations on the debridement procedure, imposed by anatomy or resorptive defects, that might prevent success of conventional root canal therapy.

This first example is a straightforward partial pulpotomy (or Cvek pulpotomy) with an MTA direct pulp cap. This patient had cerebral palsy and toppled out of his wheel chair causing a complicated (pulpal involvement) crown fracture of #10. You will note #9 was treated at this time as well, and if I recall correctly, was discolored and non-vital from a previous similar trauma. Multiple dental injuries (and traumatic injuries of all kinds) are very common in CP patients due to negative effects on balance. Fortunately, working with a pediatric dentist who scheduled OR time, the patient was seen within two days of the incident and the pulp vitality of #10 was maintained. Remember, inflammation in traumatic exposures very slowly spreads apically, and immature pulps with large vascular supplies are largely resistant to necrosis in the short term.

1-Year Recall
Please note the complete root formation.
At a 1 year recall, #10 responded normally to vitality testing. Radiographs revealed a complete formed root and a dentin barrier beneath the MTA. Astute viewers will note this success is amazingly in the absence of a coronal restoration (unfortunately, not the only time I've seen bare, unrestored MTA pulp caps succeed at 1 year recalls).

This next case is similar, although a little less conventional. As you can see in the preoperative radiograph, the root is severely dilacerated. While certainly it is possible to perform root canal therapy on this type of root (see my previous post for an arguably more challenging S curve), the difficulty level is unquestionably high. This treatment plan not only reduces the risk of instrument separation, but also saves the patient time and money, and the operator from fatigue.
The key here is that this was an asymptomatic carious pulp exposure. In the case of symptoms of irreversible pulpitis, it is generally thought that an MTA pulpotomy is a more risky procedure. It is certainly contraindicated in cases with symptomatic apical periodontitis (although I have had success direct pulp capping an immature tooth with apical periodontitis).

This last case is open to the most controversy. This patient had multiple large composite restorations across the anterior maxillary dentition. He admitted to being far more motivated by financials than esthetics. His previous composite restoration and crown had sheered off unconventionally at an oblique angle to the buccal leaving a substantial cingulum. The fractured portion had been rebonded by his general dentist. This tooth had a history of trauma over 40 years ago and some extensive external resorption is visible overlapping an obliterated pulp chamber and canal. The PDL is definitely in tact and there is no history of symptoms. The option of extraction and implant placement was discussed and encouraged. The alternative treatment plan chosen by the patient is less than ideal and the patient was more than okay with a compromised long-term prognosis. I intentionally described a grim outlook to the patient, as I do with most unconventional treatments, although here I can admit that I am confident in the predictability of the patient's choice. As you can see from the preop radiographs, conventional root canal therapy is impossible due to the irregular resorptive defect sandwiched between obliterated canal space.

I am still waiting on the general dentist to forward over a restored recall radiograph. Hopefully I will have the image to edit in by the end of the week. You can see the post space that I prepared using a 2 round bur and a gates-glidden with the tip flattened. The post space communicated with the resorptive more coronal than I anticipated, necessitating the use of MTA as a sort of resorptive cap. I feel as long as the area remains aseptic, it is reasonable to assume a successful result.

Here is a bonus case posted on our facebook page, . I'd encourage everyone to follow there (and check the backlog of case photos) for more interesting cases.

The patient's symptoms were intermittent, spontaneous, a 6 or 7 out of 10 on the pain scale, occasionally throbbing, and worse with mastication and pressure. The key history here is the patient's remark, "it feels like my gums are coming loose from my tooth."

Make the diagnosis. I have obviously helped by circling the key components.

Friday, September 16, 2011

Calcific Metamorphosis (Pulpal Obliteration) and Internal Bleaching

It has been reported that 11.6% - 33% of boys and 3.6% - 19% of girls suffer some kind of dental trauma before age 12. Internal staining is common following a traumatic injury to a tooth. Calcific metamorphosis is the partial or complete obliteration of the pulp following dental trauma. An interesting study of 168 traumatized, discolored, anterior teeth found that 47.6% were partially obliterated, 31.6% were totally obliterated, and 20.8% were found necrotic. Necrosis was more associated with fractured teeth, while pulpal obliteration was associated with subluxation and concussion injury. It was also noted that injuries suffered in the 1st and 2nd decades of life resulted in more pulpal obliteration, while those suffered in the 3rd decade resulted in necrosis more often.
To remove this discoloration, typically endodontic therapy is performed and internal, non-vital bleaching is performed. The following case is a variation of this procedure.

This 13 year old boy previously suffered a traumatic injury. Tooth #8 has discolored. The tooth is asymptomatic. Non-responsive to thermal testing, normal to percussion and probing.
It was decided to perform endodontic therapy, prior to internal bleaching to improve the esthetics of this tooth.

Partial pulpal obliteration is noted. A 1mm thick calcific barrier is found just below the level of the CEJ.

RCT is initiated and a complete calcific barrier is noted. It was decided to perform the internal bleaching without endodontic therapy.

A standard internal coronal barrier (glass ionomer) is placed over the calcific barrier to prevent internal bleach from exiting through cervical dentinal tubules and causing an inflammatory reaction in the pdl. A walking bleach technique is used. (Opalesence Endo)

After 1 week, pt returns and the internal bleach is removed. This tooth will be recalled to monitor vitality over time.

If pulpal obliteration occurs without necrosis, there may not be a need for endodontic therapy prior to internal bleaching. If a coronal barrier can be placed, without exposure (and possible contamination) of the pulpal tissue, then it would seem that internal bleaching could be performed without the need for complete endodontic therapy. Long term recall to monitor vitality will be done with this type of approach.

Adeleke O Oginni
and Comfort A Adekoya-Sofowora
"Pulpal sequelae after trauma to anterior teeth among adult Nigerian dental patients", BMC Oral Health 2007, 7:11doi:10.1186/1472-6831-7-11.

Thursday, September 1, 2011

Cone Beam (CBCT): To Use or Not to Use?

There has been some discussion about the indications for use of CBCT in endodontics. The AAE and AAOMR released a joint position statement regarding the use of CBCT in endodontics.

The section on patient selection criteria states, "CBCT must not be used routinely for endodontic diagnosis or for screening purposes in the absence of clinical signs and symptoms. The patient’s history and clinical examination must justify the use of CBCT by demonstrating that the benefits to the patient outweigh the potential risks. Clinicians should use CBCT only when the need for imaging cannot be answered adequately by lower dose conventional dental radiography or alternate imaging modalities."

I would suggest that there are times when a clinician has no way of knowing what additional information a CBCT would provide prior to starting treatment. This information may often prevent complications, such as perforation, which potentially could affect long term prognosis.

The following case is a perfect example.

This patient came to SSE for emergency treatment. #18 DX: Necrotic pulp w/ Symptomatic Apical Periodontitis. RCT initiated. 3 canals located, however a 4th distal canal is not found. 2 distal roots are apparent the pre-op film. The ML, MB and a distal canal are located. The distal is opened looking for the 4th canal. After 20-30 minutes of searching for 4th canal, the patient is re-appointed for 2 step treatment.

Upon return for second visit, the symptoms of SAP have not completely resolved. Slight vestibular swelling noted. We decided at that point to take a CBCT to help us located the 4th canal.

The CBCT clearly shows us that a perforation has been created (red arrow), and the additional canal/root is lingual to the DB canal. A sagittal view, provided only by CBCT, can provide information that is not available by conventional radiography.

With these images, the 4th canal is easily located within minutes of opening the tooth.

In this case, a CBCT provided valuable information that identified location of the 4th canal. If taken prior to starting, the 4th canal would have been located more quickly and without the small perforation in the distal.

I am not suggesting that CBCT should be used on every patient, but I am suggesting that with multiple rooted teeth, the sagittal & axial view provided by CBCT can save time and prevent endodontic complications, both of which provide justification for a more routine use of CBCT in endodontics. In our practice at SSE, the CBCT is not a profit center. We have priced these images to make them affordable to all patients. Our implementation of CBCT is to provide the highest quality of endodontic care available.