Final answer:
The question assumes the release of toxic vanadium from a dental restorative material, which is not a widely recognized concern for standard materials such as amalgams, glass ionomers, composites, or porcelain.
Step-by-step explanation:
The dental restorative material known to release toxic vanadium is not commonly discussed in literature; vanadium release is typically not a significant concern with dental materials. The common materials used for dental restoration are amalgam, which contains about 50% mercury and is known for its durability and ease of manipulation, glass ionomer, composite, and porcelain. However, mercury's toxicity has been a concern regarding dental amalgams. The statement seems to be misleading as none of the options provided (Amalgam, Glass Ionomer, Composite, Porcelain) are known to release vanadium as a toxin. If vanadium release were a concern, it is not typically associated with these dental materials.