Dental fillings or tooth restoration are treatments used to restore the function, integrity and morphology of missing tooth structure caused by caries or external holes. It is applied in prosthetic dental treatment, periodontology and aesthetic dentistry. They are of two broad types, direct and indirect, and are further classified by location and size. Dental veneers, inlays and onlays, porcelain teeth, crowns, dental implants, and dental bridges are alternative materials to dental fillings.