A dental superstructure securable to a protruding dental abutment, related assembly and method of design are provided. The dental superstructure is designed to mimick a tooth and is perforated to create a drop-shaped screw conduit for screw insertion and advancement. The screw conduit includes an insertion portion extending substantially conically outwardly from an inlet to enable advancement of an inserted screw along an insertion axis and a spherical angulation portion extending from and communicating with the insertion portion to allow angulation of the screw from the insertion axis to an implant axis. Buccal and/or lingual contours of the screw conduit may be respectively arched outwardly and inwardly from the insertion axis to adapt to screw advancement needs. The dental superstructure may be part of an assembly for a dental implant in combination with an osseointegrable implant including the protruding dental abutment; and a dental abutment screw.