What are the ends of periodontal ligament fibers that embed in bone and cementum called?

The ends of periodontal ligament fibers that embed in bone and cementum are referred to as Sharpey's fibers. These fibers play a crucial role in the attachment of the tooth to the surrounding bone by anchoring the periodontal ligament either to the alveolar bone (the bone housing the teeth) or to the cementum (the calcified layer covering the tooth roots).

Sharpey's fibers are specifically embedded in the bone and cementum, providing strength and support to the tooth structure. Their organization and attachment are vital for maintaining tooth stability, enabling the periodontal ligament to function effectively during chewing and other activities that might exert force on the teeth.

The other options represent different types of fibers or structures that do not specifically refer to the embedding within bone and cementum. For example, collagen fibers are the primary structural proteins in connective tissue but do not specifically designate those fibers that attach to bone and cementum. Ossifying fibers and reticular fibers have different functions and locations, further emphasizing the unique role of Sharpey's fibers in periodontal health and function.