Willoughby D. Miller

He traveled to Edinburgh to continue his studies, but financial problems caused him to move to Berlin where he was assisted by an American dentist Frank Abbot.

[2] After graduating, Miller returned to Berlin where he worked at first in Abbot's dental office and pursued his interest in the emerging science of microbiology.

Bacteria had been observed inside carious dentin by Underwood and Miles in 1881, and these researchers also proposed that bacterial acids were necessary for removing the mineral of teeth.

[6] He worked in the microbiological laboratory of Robert Koch in Berlin and began numerous research projects that introduced modern biological principles to dentistry.

The principles of the chemo-parasitic theory were bolstered by the descriptions of bacterial plaque on tooth surfaces independently by GV Black and by JL Williams in 1898.