Amsterdam prosecutors say 64-year-old Hok Tong Kwee permanently ruined the teeth of at least 10 patients after losing his license in 2004. Kwee denies malpractice, saying he only took "acceptable" risks.
But when prosecutors called on victims to come forward last year, hundreds responded.
Prosecutors say he billed for phantom procedures, tried to pass off a synthetic filling as a crown, improperly placed multiple bridges in the mouth of one patient, and used dirty tools.
Prosecutors have demanded a 30-month sentence. The verdict is due Sept. 26.
In the other case, 55-year-old Ben Verlinden was sentenced to four months by judges in Haarlem on Friday for mistreating four patients after having been stripped of his license in 2001. He had been banned twice before for mistakes that prosecutors said included "drilling teeth to bits."
When medical investigators tried to catch him at his offices last year, he fled via a fire escape. He was caught later, instruments in hand.