Candee Mills pulled out a small piece of white bone from a pouch.
"This is part of my jawbone," she explained.
It's a piece that fell out of her skull after she paid a visit to dentist Robert Mansueto.
"Oh my God, it was the most excruciating pain," she recalled.
She went to Mansueto's Coronado dental office in 2001 because she needed a specialist for implants.
"He sucked me in with these ads that said he was a pioneer in the field," she said.
Mansueto pierced her sinus cavity and placed implants manufactured for him in a machine shop in her mouth. The implants failed.
"I went to my own dentist and he said, oh my God, your mouth looks like hamburger meat."
Candee Mills isn't alone. The I-Team found other serious malpractice cases against Mansueto. Red flags about his work were raised as early as the 1990s.
He spent 11 years on probation before losing his license.
The Dental Board of California wrote that Mansueto is "sloppy" and makes "errors in judgment that put the public at risk."
The I-Team uncovered more allegations from his wife in his divorce records. According to court documents, she said he used "marijuana laced with PCP" and "snorts cocaine." Mansueto's wife later recanted her testimony.
"It's very scary," said attorney Deborah Wolf, talking about Mansueto's history of dentistry. She represented 9 patients against Mansueto.
"He was very uncaring," she said.
She fought for his license to be revoked, thinking that would stop him. But the I-Team learned that he's still picking up the drill on unsuspecting patients.
William McArthur of Oceanside said, "Talk about picking yourself off the floor and saying what have I done to myself."
He is a recent patient of Mansueto. McArthur ended up in Mansueto's chair after reading an ad in the Sunday Union-Tribune.
"He's advertising as an American doing business in Tijuana," McArthur pointed out.
The ad mentions "Dicoa Dental" and implants at reduced prices. So McArthur went to the office for prep work.
The Dicoa Dental office is located just south of the U.S. Mexico Border in Tijuana, a five minute walk from the border.
McAurthur said after meeting with Mansueto he became suspicious because there were no doctor's certificates on the office wall. So he did some research on Mansueto.
"Here is a guy who is operating without a license, he doesn't have any more credentials that my gardener."
He called the I-Team, and reporter Lauren Reynolds tried to reach Mansueto at an address listed as his in Coronado. But no one answered.
So Reynolds and a photographer went to Dicoa Dental in Tijuana. They didn't find Mansueto there but did speak to two employees of Dicoa Dental.
"Did you know that Robert Mansueto lost his license in California?" Reynolds asked dentist Tania Calvo and office assistant Karen Perec.
Calvo responded, "No."
Perec said she was aware of that and that Mansueto does not touch the patients. She said he only comes in once in a while to drop of products.
Reynolds asked why his name, picture, and credentials were displayed prominently on their Web site, to which Perec responded, "It's just advertising."
Mansueto does not have any license to practice dentistry in Mexico.
Since the visit of the I-Team to Dicoa Dental, his name and picture have been removed from their Web site. The I-Team reported what they found to the Baja Health Department and Union Tribune.