My PEAK Presentation: External Lesion Therapy

Alex Frisbie, DMD

The vast majority of cases identified as “internal resorption” are likely misdiagnosed external lesions — some that have progressed to the pulp space. Some of these can easily be distinguished with an angle-shift periapical or CBCT, but others are more difficult to distinguish. According to literature and discussions with endodontists, true internal resorption is rather uncommon. Still more uncommon is a resorptive-type lesion arising in the coronal aspect of the tooth. In the interest of brevity, please forgive the absence of the patient’s unremarkable medical history, procedural minutia, and literature citations — all of which I can share in person at future PEAK events. I realize I am no Ruddle or Rankow but as my PEAK colleagues say this is why we “practice” dentistry. Even in my short career, this group has given me the resources and confidence to enhance every aspect of my professional self. Leaders like Dr. Rick Knowlton have taught me to focus on the special relationship general dentists enjoy with their patients, which I truly believe is the best motivator for growth.

A 65-year-old female patient with an existing crown about ten years old presented complaining of pain to mastication. Years earlier the patient had been referred to an endodontist for similar symptoms. A root fracture was suspected and the tooth was recommended for extraction.

Clinically, the tooth showed pain to percussion and a sharp lingering response to cold. Localized pressure with a tooth sleuth produced pain, however the full coverage crown made identification of decay or a fracture difficult. A pre-procedural diagnosis of irreversible pulpitis with symptomatic apical periodontitis was made, and the patient elected to remove the crown to assess for fracture or an active carious lesion.

After removing the crown, a small (0.5×0.5mm) void was found near the distolingual line angle in otherwise solid dentin with no obvious decay. Figure 1 This defect was unroofed revealing a large lesion continuous with the pulp chamber with small tags of vital tissue. Figure 2

A CBCT suggested the lesion did not communicate with the external surface of the tooth. Figure 3 The patient was counseled on risks of endodontic therapy that the lesion may perforate the tooth beyond where we can visualize, that therapy itself may result in perforation, or that a fracture may exist below the level of the lesion. The patient elected to pursue endodontic therapy, understanding the risks of procedure and less-than-optimistic prognosis.

Upon access, the lesion was found to be a “dead end” lesion prolapsing from the distolingual wall of the pulp chamber. No cracks or perforations were identified, and treatment was completed. Figure 4

A dual cure bis-acryl core material was used to seal the coronal chamber as well as the defect, the preparation refined and provisionalized. Figure 5 The patient enjoyed immediate relief of symptoms, and the tooth was monitored for several weeks with no sequelae before fabricating a new crown. Figure 6

The patient has moved out of state again, but when I called her ten months post-op she said her tooth felt great and thanked me for pursuing a creative solution for her tooth.