The most important diagnostic test to differentiate between an acute periapical abscess and a phoenix abscess is: PGCEE MDS 2022

 # The most important diagnostic test to differentiate between an acute periapical abscess and a phoenix abscess is: 

a) Pulp testing

b) Radiographs

c) History

d) Percussion

The correct answer is B. Radiographs.

Phoenix abscess is an acute inflammatory reaction superimposed on an existing chronic lesion, such as a cyst or granuloma. The exacerbation of a chronic lesion is most commonly associated with the initiation of root canal therapy in a completely asymptomatic tooth. In such a tooth, radiographs show well-defined periradicular lesions.