Patient: 30-year-old male in excellent health

Chief Complaint: Severe pain of 3 days duration

Dental History The patient presented with no recent dental procedures and a deep occlusal amalgam filling placed an unknown number of years earlier.

Significant Findings: Tooth #18 presented with a crack-mesial marginal ridge (found to be crown-limited upon endodontic access), severe percussion sensitivity, no cold thermal response, class 2 mobility, and the periapical radiograph demonstrated a large periapical radiolucency circumscribing the distal root.

Diagnosis: Necrotic pulp, symptomatic periapical abscess with a radiolucency

Prognosis: Good

Treatment Plan: Nonsurgical endodontic therapy (#18)

Treatment Description with Special Considerations: This tooth presented as a classic Radix Entomolaris (lingual) as opposed to a Radix Paramolaris, which would be on the buccal due to the fact the "middle" root, shifted mesially when the radiograph was taken from the mesial.

Dr. Herbert Schilder taught his residents to "never force a case". If you're worried about the next patient in the schedule, or having to finish the root canal treatment iby the end of an appointment, the result will likely be compromised.

This case required a challenging posterior access and the patient was prepared for multiple visits:

First Visit: Carefully designed straight-line access to all canal orifices, cleaning and shaping of all root canal systems while flushing copiously with irrigant (5.26 % NaOCl and occasional 17% EDTA), and finally length determination.

Second Visit: Final cleaning and shaping of the distal root and entomolaris root was performed. The cones were fit with appropriate tug back and obturation completed in these roots. The mesial root was complex and required more time, so calcium hydroxide was replaced in the mesial root, the tooth was temporized and the patient scheduled for a third visit 2 weeks later to finish the mesial root and place a core.

Third Visit: Final cleaning and shaping of the mesial root, cones fit with tug back and final obturation. A bonded composite core was placed and the patient was refered back to his general dentist for a full-coverage restoration.

Key Learning Points:

1. Don’t rush the case

2. Direct line access

3. Very precise length determination

4. Schedule an extra appointment if necessary

5. A narrow taper is not ideal but may be necessary in some cases like this with severe curvatures and narrow roots

6. Avoid spacer when temporizing between visits

7. Passive instrumentation with multiple recapitulations using precurved K-files

8. Copious irrigation