Dr. Frank Portell, D.M.D., M.S.
Title: Management of severely curved canals
Background / Chief Complaint: A 42 y/o woman presented with a chief complaint of pain for the past week when
chewing over the area of tooth #32. Medical history was non- contributory, ASA 1.
Clinical Tests: Tooth #32 was painful to percussion, and was non-reactive to cold (Endo Ice). Both periodontium
and oral mucosa were within normal limits (WNL.) Tooth #32 had an opposing tooth and was functional.
Radiographic Findings: Radiographic examination revealed normal periradicular tissues and evidence of decreased
pulpal space. Anatomically, both mesial canals were severely curved.
Diagnosis: Pulpal: Necrotic pulp Periapical: Sympotmatic apical periodontitis
Treatment: Canals were prepared with hand files and Tulsa Protaper Gold F1-F3 rotary files. Glyde gel lubricant
and 5.5% NaOCl2 were used to canal irrigation.
Three canals were thermoplastically obturated with gutta- percha and ZnOE (Grossman) sealer.
Post obturated with gutta-percha and ZnOE (Grossman) sealer.
Discussion: This case highlights the importance of straight access and coronal preflaring canal preparation with
flexible rotary files and the advantage of 3- Dimensional thermoplastic obturation of the root canal system.
Pre-op / Post-op Radiographs:
Dr. Nathan Schoenly, D.D.S.
Title: Non-surgical Retreatment of C-Shaped Canal
Background / Chief Complaint: The patient was referred for evaluation and treatment of Tooth #18
(Mandibular left second molar). She reported root canal therapy was previously performed in 2012 by
an endodontist in the Greater Washington area who reportedly said “this may not last very long.” She
reported localized buccal vestibular swelling and pain exacerbated by chewing.
Clinical Tests: Marked sensitivity to percussion and palpation to the associated buccal vestibule. No
Radiographic Findings: Periapical radiograph shows apical rarefaction associated with fused roots of
Tooth #18. Previous obturation of canals appears off-centered suggesting a potential missed canal distal
to the obturated canals. Additionally, the apex appears “blunted” suggesting pathologic apical
resorption. A CBCT scan was exposed and reveals a C-shaped canal (Fan Category II- “semicolon”
configuration) apparent in axial slicing. Further apically-positioned axial slices revealed distinctly missed
and unobturated distobuccal canal. This canal was further visualized on sagittal slicing.
Diagnosis: Previously Treated with Symptomatic Apical Periodontitis
Treatment: Access was made through PFM crown, previous obturation material removed with gatesglidden
drills and Protaper retreatment files using chloroform solvent and 2% NaOCl irrigation. Canals
were retreated and additional distobuccal canal was located in middle third of distal root and cleaned
and shaped using ProTaper Gold files. Ca(OH)2 paste was placed to length for 10 days and the patient
returned for second visit reporting a cessation of symptoms. Final irrigation with 17% EDTA followed by
2% NaOCl. Apical third of canals was obturated using white ProRoot MTA to improve seal at resorbed
apex and backfilled with thermoplasticized gutta-percha. She has been placed on a 6-month recall for
evaluation of periapical osseous healing.
Discussion: The treatment of C-shaped canals is complicated by an excess of canal surface area that
cannot be accessed directly for proper disinfection. Further complicating treatment of these particular
teeth is that they are not amenable to traditional microsurgical techniques. Due to the thickness of
buccal bone and proximity to the inferior alveolar canal, periradicular suirgery is typically not performed
on mandibular second molars. This makes non-surgical retreatment the treatment of choice as the only
other alternatives are intentional replantation or extraction followed by replacement with an implant.
The other complicating factor with this particular tooth was the degree of pathologic apical resorption
making the creation of an apical seal challenging. To this end, ProRoot MTA was used in an apexification
protocol to improve the apical seal.
Pre-op / Post-op Radiographs and CBCT Images: