Which of the following is not a clinical criterion to evaluate treatment outcome?
Endodontic treatment outcome predictors using PA radiographs and CBCT imaging have been shown to vary and also are influenced by patient inclusion and exclusion criteria. Historically, PA radiographs and physical examinations were used to determine the success of endodontic treatment, and the absence of posttreatment periradicular radiolucencies and symptoms was considered the criterion for success.
The clinical criteria to evaluate treatment outcome may be:

No evidence of a sinus tract 
No swelling present 
No response to percussion or palpation 
Absence of a radiolucency may be a radiologic feature to evaluate the success of treatment.

Ref: Cohen pathways of Pulp 11th ed page no 56
Absence of a radiolucency
No evidence of a sinus tract
No swelling present
No response to percussion or palpation