Patient: 66 year old male with a recent hip replacement
Chief Complaint: sensitive to cold

Dental History:
The patient was undergoing a full mouth rehabilitation by a prosthodontist and during the treatment planning was adamant having a bridge instead of an implant replacing the lost first molar. The maxillary left second bicuspid (#13) had very little remaining coronal tooth structure left after caries control. The maxillary left first bicuspid (#12) and the maxillary left second molar had been prepared and were serving as abutments for a temporary bridge. There was concern that tooth #13 would compromise the fixed prosthesis and become a weak link if used as a second mesial abutment for the final restoration.

Significant Findings: All general oral exam findings were within normal limits. Tooth #13 responded within normal limits to cold thermal stimulation (ice). Periodontal findings were within normal limits with probing depths between 2-3mm for all posterior teeth tested in the sextant. Percussion, palpation, and mobility findings were unremarkable.

Pulp and Periradicular Diagnosis: Normal pulp status with a caries exposure and a normal periradicular periodontium

Treatment Prognosis (Tooth #13): The prognosis was poor-to-guarded if the tooth was to be restored to function as a second mesial bridge abutment. The prognosis would be guarded to fair if the tooth was to be restored to function as a single crown with the occlusion protected by an adjacent implant replacement of the first molar but that plan was unacceptable to the patient. The prognosis was good if the tooth was to be treated, decoronated, and buried out of function simply to preserve bone and the option of a future implant.

Treatment Plan (Tooth #13): Nonsurgical endodontic treatment, decoronation, and coronal sealing with a layer of Geristore.

Special Considerations of Performed Treatment:
Endodontic treatment of tooth #13 was uneventful with the filling of an interesting complex apical trifurcation. After obturation with gutta percha and zinc-oxide based sealer (Kerr) via the vertical compaction of warm gutta percha technique, 3mm of coronal root canal space was left to be filled with Gerstore bonded with Tenure. The coronal portion of the tooth was troughed with a “moat” around the canal leaving a very thin strip of peripheral dentine to be finished down after removal of the rubber dam for final preparation of the decoronated crown. This allowed adequate depth of the Geristore layer to be finished down to the ideal subgingival level.

After removal of the dam the thin peripheral wall of dentine as prepared down to the height of the osseous level being careful not to remove any bone. Bleeding was stimulated so that a clot would form over the submerged occlusal surface of the root and the gingival area of the temporary bridge pontic was relieved in a way to cover the buccal and lingual tissue areas peripheral to the root yet creating adequate space between the pontic and root for a clot to form.

Decoronation is an accepted technique that allows a root to remain and preserve osseous contours that would otherwise be resorbed with the extraction of a tooth. The patient may want to revisit the option of an implant replacement of the first molar at a future date should the long span bridge fail. Retaining the second bicuspid root is a prudent plan that will preserve valuable osseous structures well into the future.

Key Learning Points:

1. An endodontist should thoughtfully communicate with the treatment team understanding the needs of the specific patient before initiating routine endodontic treatment

2. Decoronation is a rare but occasionally very useful treatment option

3. Understanding the proposed function of a tooth before treating it is essential for successful oral rehabilitation