According to the American Association of Endodontists Case Difficulty Assessment, what is the degree of difficulty of root canal treatment on a single tooth with INTERNAL RESORPTION?

Correct answer: D. High difficulty

• A. Difficulty can be assigned directly. The AAE form is a structured checklist, and resorption is an explicitly listed criterion that places a case in the high-difficulty tier on its own.
• B. Minimal difficulty describes the straightforward case: an anterior or premolar, a straight canal, no unusual anatomy, a cooperative patient with no complicating medical history. Internal resorption is the opposite of this profile.
• C. Moderate difficulty covers findings such as moderate canal curvature (10–30°), a crown with extensive restoration, or a second molar position. Resorptive defects sit a tier above these.
• D. CORRECT. The AAE Case Difficulty Assessment Form places resorption — internal or external — in the HIGH DIFFICULTY column, alongside canal calcification, apical resorption, previous treatment complications and open apices. Internal resorption creates an irregular ballooned defect that files cannot mechanically reach, so the lesion must be disinfected chemically and obturated with a technique capable of filling an irregular space. High difficulty means the case is a candidate for referral to an endodontist.

Note: The AAE form scores three groups: patient considerations (medical status, anaesthesia difficulty, cooperation), diagnostic and treatment considerations (diagnosis, radiographic difficulty, position in arch, tooth isolation, morphology), and additional considerations (trauma history, previous treatment, periodontal condition). A single HIGH entry anywhere makes the whole case high difficulty. Management of internal resorption: thorough NaOCl irrigation, calcium hydroxide interim dressing, then warm vertical or MTA obturation — and remove the granulation tissue promptly, since untreated internal resorption is progressive and will perforate.