Endodontic therapy is contraindicated for a single-rooted tooth that has:: (A) Discoloration, (B) An acute apical abscess, (C) A vertical fracture of the root and an associated deep periodontal defect, (D) A horizontal fracture of the root and an associated deep periodontal defect
Answer is C. The vertical fracture of teeth has poorer prognosis, in addition to this presence of periodontal problem contraindicates root canal therapy.