What anatomical structure does a periodontal probe touch at the base of a deep periodontal pocket?

A periodontal probe is designed to measure the depth of periodontal pockets and assess the health of the supporting structures of teeth. When a periodontal probe is inserted into a deep periodontal pocket, it reaches the base of the pocket, which is marked by the junctional epithelium.

The junctional epithelium is a critical component of the periodontium, serving as the attachment point between the tooth surface and the gingival tissues. It is a non-keratinized stratified squamous epithelium that forms a seal around the tooth, playing an essential role in preventing bacteria from entering the deeper periodontal tissues and maintaining the attachment of the periodontal ligament fibers.

In a healthy state, the junctional epithelium should be situated at or near the CEJ (cementoenamel junction). However, in cases of periodontal disease, the probe can penetrate deeper into the pocket, reaching this structure. Therefore, identifying the junctional epithelium as the point of contact indicates the depth of disease progression.

Other options, while related to periodontium health, do not represent the structure the probe contacts at the very base of the pocket. The gingival margin is the edge of the gum tissue but does not represent the flooring of