"If you didn't look at it in person and you heard it coming out of the room you would think that they're cutting their arms and legs off," he said. "I mean it's… the screams are bloodcurdling, they're terrifying."
He said that he has "no doubt that in many cases" the experience is traumatizing to the children and that he was even more disturbed by the pricey and sometimes invasive work performed when he thought cheaper options would have been adequate.
"I see a lot of unnecessary work," he said. "I see a lot of overtreatment."
After a run of bad publicity, Small Smiles hired respected pediatric dental expert Dr. Steven Adair in the summer. His job is to oversee standards and training in all the company's clinics. One of the things he's been emphasizing to company dentists, he says, is that papoose boards should only be used when necessary.
As for the claims of some former employees of unnecessary care, Adair told ABC News, "I haven't been presented with evidence" of that.
Small Smiles insists that the company's clinics provide a valuable service to hundreds of thousands of low-income kids, including many with severe dental problems and few other dentists to turn to.
Meanwhile, there have been some policy changes. Dr. Toni Adderly, who runs a Small Smiles clinic in Washington, D.C., said parents can now watch their children being treated.
"They're able to … observe what's going on with their children," she said, and "they're told they can come back."
Adderly says she feels no pressure to produce profits, but Sansbury says that was not her experience at a different clinic she left in the spring.
"It seems as if the money situation prevails over what's best for the children in that regard," she said.
Several states and the federal government are looking into Small Smiles for possible Medicaid fraud.