When the Foundation heard of Yelkov's experiments, they raided his lab, and found nine of his test subjects, seven of whom had died, and several extracted specimens and vials of the serum. Grigori, assuming this meant he should continue his work, although Grigori had most likely just been infected and died. However, he then discovered that SCP-1994 was contagious, as it caused a pandemic.
Yelkov managed to stabilise one, subject 019, although he had to lobotomize her in order to prevent her from dying, and sent extracted tooth specimens to Dr. Yelkov then performed experiments on an unknown number of humans involving exposure to the serum, which caused the intensely painful process of causing human teeth to grow out of the subjects, resulting in many of them dying.
Murdering the man, Yelkov performed experiments on the tooth fairies which eventually caused them to produce SCP-1994-1, a serum which could cause human teeth to grow. During his search for a method, Yelkov was informed of a man living with a mystical clan of tooth fairies (SCP-478) and set out to find him. Grigori with finding a way to synthesize human teeth in order to satisfy his dental clients.
