Polycrystalline elements include a substrate and a polycrystalline table attached to an end of the substrate. The polycrystalline table includes a first region of superabrasive material having a first permeability and at least a second region of superabrasive material having a second, lesser permeability, the at least a second region being interposed between the substrate and the first region. Methods of forming a polycrystalline element involve attaching a polycrystalline table including a first region of superabrasive material having a first permeability and at least a second region of superabrasive material having a second, lesser permeability to an end of a substrate, the at least a second region being interposed between the first region and the substrate. Catalyst material is removed from at least the first region of the polycrystalline table.