Parulis — mucosal opening of a chronic sinus tract from an endodontic infection.

A parulis ("gum boil") is the soft-tissue opening of a chronic dental sinus tract from pulpal necrosis. It is composed of granulation tissue and often exudes pus. The underlying cause is endodontic. A pyogenic granuloma is a red vascular pregnancy-related lesion and is not linked to a periapical radiolucency.