Explain the Radiographic Success of Root Canal Treatment

Elimination or lack of development of an area of rarefaction (= Radiolocency )  for a minimum of I year after treatment . This includes lamina dura and restoration of periodontal space (IMP): 

Radiographic success is the absence of an apical radiolucent lesion. This means that a resorptive lesion present at the time of treatment has resolved or, if there was no lesion present at the time of treatment, none has developed.

Success:

A. This radiolucent lesion has the radiographic appearance of a periodontal lesion. The initial radiograph indicates bone loss from the crest of the ridge around the apices of the tooth. Periodontal probing demonstrates that the gingival sulcus is intact.

B. Root canal treatment completed.

C. Four-year recall shows resolution of the radiolucency.