What is a common sign of periodontal disease?

Loose teeth is indeed a common sign of periodontal disease. This condition affects the supporting structures of the teeth, such as the gums and bone, leading to the loss of attachment and stability of the teeth. As the periodontal disease progresses, it can cause the gums to recede and the bone to deteriorate, resulting in increased mobility of the affected teeth.

In contrast, tooth whitening is not associated with periodontal disease; rather, it is typically a cosmetic procedure aimed at improving the appearance of teeth. Increased salivation does not indicate periodontal issues but may be linked to other conditions or reactions. Similarly, while high sensitivity to cold can occur, it is more closely related to enamel wear, cavities, or other dental conditions rather than being a direct sign of periodontal disease.