Which of the following is a characteristic of periodontitis?

Periodontitis is marked by specific clinical features that differentiate it from other periodontal diseases, particularly gingivitis. The correct answer focuses on two critical aspects: attachment loss and the formation of periodontal pockets.

Attachment loss refers to the detachment of the periodontal ligament from the tooth surface, resulting in the loss of supporting structures that keep the tooth anchored in the jawbone. This detachment is a hallmark of periodontitis and is measurable through clinical attachment level assessments. The formation of periodontal pockets occurs when the gum tissue pulls away from the tooth due to this attachment loss, creating spaces that can become depths vulnerable to plaque accumulation and further infection.

In contrast to this, the absence of bleeding upon probing is typically seen in healthy gingival tissue, not in periodontitis, where inflammation usually leads to bleeding. Increased sensitivity to hot and cold is not a defining characteristic of periodontitis and can occur due to other dental issues like pulpitis. The presence of calculus alone does not indicate periodontitis; while calculus (tartar) is associated with periodontal disease, its presence without other indicators does not confirm it. Thus, the combination of attachment loss and pocket formation is essential in diagnosing periodontitis.