Christopher Schutzius, 17, of Blue Island, died of an infection that the Cook County Medical Examiner says was contracted after a root canal.
Dental experts say it's extremely rare for even a botched root canal to result in death.
On Friday, relatives of the patient are questioning whether the procedure should have been done at all.
Schutzius's loved-ones are stunned by his death.
"He'd give you the shirt off his back. He was a wonderful kid. It's hard to believe he's not with us anymore," said his foster brother Richard Garcia.
The 17-year-old high school senior died Wednesday more than a week after getting a root canal at this clinic in Blue Island called Dental Dreams.
When Schutzius fell ill a few days after the procedure, family members initially thought he had the flu.
"His eyes were real wide. He looked like, he was sweating. He was kind of pacing around, too. He looked confused, too, like he didn't know where he wanted to go," said his foster cousin David Saenz.
The Cook County Medical Examiner says Schutzius died of the toxic infection sepsis resulting from the root canal.
His relatives now question whether the procedure was even necessary, saying Schutzius initially went to the clinic to replace a loose filling.
"He was a perfectly healthy kid. Never smoked, never drank, never did drugs," Saenz said.
Relatives say Schutzius was not given antibiotics, just some over-the-counter medication.
Dr. Christopher Wenckus, Head of Endodontics at the University of Illinois at Chicago School of Dentistry says antibiotics are not standard after a root canal.
He says it's almost unheard of, however, for the procedure, even if improperly performed, to result in death.
"If this is indeed linked to the root canal, it's extremely, extremely rare," Wenckus said. "There's around 16 million root canals performed in this country every year, and as I look back at my 35 years of experience, I haven't heard of that happening before."
Schutzius was due to graduate high school this spring and had hoped to become a mechanic.
"He was going to succeed. He was a very nice kid, had the demeanor for it, and I think he had the capability of becoming a good mechanic if that's what he chose to do," said Eisenhower High School Associate Principal Philip Henry.
"I loved him like a brother. We're going miss him. And hopefully he's good up there where he's at," Saenz said.
ABC7 called Dental Dreams, the clinic where Schutzius had his root canal.
A woman who answered the phone said they had no comment on the case and hung up the phone.
We also tried to check with the Illinois Department of Professional Regulation to see if the clinic has past complaints on file, but the office was closed because of the Lincoln Holiday.