Das Problem der dentalen Fokalinfektion und ihre Bekämpfung durch die konservierende Zahnheilkunde.

With physicist Fritz Giesel, Walkhoff on December 28, 1895 Walkhoff did the first dental radiograph on his own teeth. Later, Walkhoff was "responsible for the shift to an everyday use of camphorated chlorophenol to sterilise the canals" (Xavier Riaud, "The first dental radiograph (1896)" http://medcraveonline.com/JDHODT/JDHODT-09-00325.pdf).

See also Walkhoff, "Gutachten über die Wirkung des Chlorphenol-Kampfer-Menthols," Zahnärztliche Rundschau, 39, (1930).