What does cementum primarily cover?

Cementum is a specialized calcified tissue that primarily covers the root of the tooth. Its main function is to anchor the periodontal ligaments, which attach the tooth to the surrounding alveolar bone, thus playing a vital role in the tooth's stability. Cementum also serves to protect the underlying root dentin and aids in the repair of the root if it becomes damaged. The thickness and composition of cementum can vary, but it is essential for maintaining the integrity of the tooth within the dental arch.

The other options refer to structures that are not covered by cementum. Enamel, for example, is located on the crown of the tooth and is the hardest tissue in the human body, while the cusp tips are part of the enamel-covered surfaces of the teeth. Periodontal ligaments are supportive tissues but are not covered by cementum; rather, they attach to the cementum on one side and to the alveolar bone on the other. Thus, the primary role of cementum is specifically related to the root of the tooth.