If a tooth is replaced with a silicone plug, which structure must be retained for the plug to erupt?

• A. The dental lamina
• B. The periodontal ligament
• C. The dental pulp
• D. The enamel organ

Answer: (A)

The ability for an implanted plug to erupt relies on having a preexisting eruption pathway to the surface. The dental lamina is the epithelial band that marks where teeth will form and, crucially, helps establish the eruption corridor through the jaw. If a tooth is replaced by a silicone plug, keeping the dental lamina intact preserves that channel from the socket up to the oral surface, allowing the plug to erupt along the path. The other structures are either internal components of a tooth or rely on a tooth with a root and surrounding ligament to generate eruption forces, which wouldn’t provide a pathway for a plug on its own. Hence, retaining the dental lamina is essential for the plug to erupt.