title: In appreciation of Henry J. Van Hassel.
authors.forename: Samuel O
authors.initials: SO
authors.lastname: Dorn
mesh_terms: D004708:Endodontics / Q000266:history*; D049673:History, 20th Century; D049674:History, 21st Century; D010506:Periodicals as Topic / Q000266:history; D012953:Societies, Dental / Q000266:history; D014481:United States