D2750, D2751, and D2752 are codes used in the dental industry to classify specific types of dental crowns and restorations. D2750 refers to a crown made of porcelain fused to metal, D2751 is a crown made of porcelain, and D2752 is a crown made of other materials, such as resin or ceramics. The main differences lie in the materials used and their respective applications, affecting aesthetics, strength, and cost. Each code helps dental professionals specify the type of restoration being provided.