What tissue is visible when observing a cross-section of the periodontium adjacent to the crown of the tooth?

When observing a cross-section of the periodontium adjacent to the crown of the tooth, the gingiva is the tissue that is immediately visible. The gingiva, or gum tissue, surrounds the neck of the tooth and is an essential component of the periodontium, which includes supporting structures around the teeth.

Gingiva provides a protective barrier against bacteria and is involved in the attachment to the tooth surface. It consists of a layer of epithelial tissue and underlying connective tissue, which plays a crucial role in the overall health of the periodontal structures.

While other tissues such as the periodontal ligament, alveolar bone, and dentin are critical components of the periodontium, they are not immediately adjacent to the crown in a cross-sectional view. The periodontal ligament is found between the tooth root and alveolar bone, while alveolar bone supports the tooth roots beneath the gingiva, and dentin is part of the tooth structure itself. Therefore, observing a cross-section in this context would highlight the gingiva as the primary visible tissue surrounding the crown.