Tooth associated with Persistent apical periodontitis

Functional retention of the tooth : persistent lesion while remain asymptomatic function for an extended period of time .

-Patient's goal is to retain his tooth without pain, it may not need to complete healing , but follow up .

- Uncertain healing : if sign or symptoms of persistent infection ( progressive enlarging periapical radiolucency , periodontal pocket formation , sinus tract )

- Further retreatment is needed.

- To determine that the case has persistant periapical periodontitis, we should determine the function of the tooth and the healing is it proper or not.

- We should do complete evaluation to the case before start treatment " determine if the tooth is restorable or not, can I remove obturating material or not "