Articaine HCL is a dental local anesthetic. It is the most widely used local anesthetic in many European countries and can be used in many countries around the world. The amide structure of aldicaine is similar to that of other local anesthetics, but its molecular structure differs depending on the presence of the thiophene ring rather than the benzene ring. Atacaine is special because it contains additional ester groups that are metabolized by the esterase in the blood and tissue.