Under the 2017 classification, what is the status of any site with clinical attachment loss?

In the 2017 classification of periodontal diseases, the presence of clinical attachment loss (CAL) is a key factor in distinguishing periodontitis from other periodontal conditions. Clinical attachment loss indicates that the supporting structures of the teeth, including the bone and connective tissue, are compromised, which is a hallmark of periodontitis.

When clinical attachment loss is observed at a site, it signifies that there has been damage to the periodontal attachment apparatus, categorizing that site as having active periodontal disease. In contrast, gingivitis is characterized by inflammation of the gingiva without attachment loss, and both healthy and normal sites do not exhibit any form of attachment loss. Therefore, a site with clinical attachment loss falls squarely under the definition of a periodontitis site in the context of the 2017 classification, as it reflects an irreversible condition that has progressed beyond the initial stages of periodontal disease.