Ace the NDEB 2026 – Get Set to Shine on Canada’s Dental Exam!

The main supportive and most numerous PDL fiber is the oblique fiber. This is because the oblique fibers are located at an angle between the root and the alveolar bone, providing strong resistance to forces applied to the tooth. The other options, horizontal, vertical, and alveolar crest fibers, are also important but not the main and most numerous supportive fibers. Horizontal fibers run parallel to the root surface and are important for stabilizing the tooth, while vertical fibers extend from the tooth root to the alveolar bone and help resist vertical forces. Alveolar crest fibers are located at the cervical third of the root and help resist bitting forces. However, compared to oblique fibers, these other fiber types are not as numerous or provide as much support. Therefore, the correct answer is C Oblique.