LOS ANGELES (CBSLA.com) — A network of children’s dental clinics accused of pushing unnecessary procedures on kids and using tainted water in dental procedures is also the recipient of millions of taxpayer dollars annually from the state’s insurance program for low-income patients, an investigation by CBS2’s David Goldstein has uncovered.

Children’s Dental Group first came under scrutiny in September, when CBS2’s Michele Gile broke the news that several patients of the group’s Anaheim clinic came down with bacterial infections. In the subsequent two months, dozens of other children reported infections.

Soon after, the Orange County Health Care Agency tested the clinic’s water and found it tested positive for mycobacteria. Health officials ordered the clinic to stop using the water in dental procedures. The clinic was permitted to resume using its water earlier this month.

A lawsuit filed earlier this month alleges fraud and medical malpractice at the clinic. The lawsuit claims a 6-year-old boy with autism was given two baby root canals without the use of local anesthesia. Instead, the boy was strapped into a “straightjacket-like” device, the lawsuit says.

Now, two former employees who spoke on the condition of anonymity say the clinics frequently push kids into unneeded dental procedures.

“It’s based on quantity, not quality,” a former employee said. “How many children can you bring in? How many numbers can you raise?”

The clinic’s business model encourages the practice, another former employee said.

“They get paid by procedure,” the former employee said. “So, the more procedures you do, the more money you’re going to make off that particular patient.”

Parents of former patients are accusing the clinics of similarly predatory behavior.

Cecilia Roman, the mother of a 6-year-old patient, said she told the clinic not to pull any of her child’s teeth. But a dentist at the group’s Anaheim clinic pulled three of her daughter’s teeth anyway, Roman said.

Leonor Oliver says his 5-year-old daughter received five root canals and two cavity fillings in one day at the Anaheim clinic. She soon suffered from a debilitating infection.

“They ruined her life,” Oliver said. “Her childhood has to be limited now.”

The clinics rely heavily on revenue derived from Denti-Cal, part of the state’s Medicaid insurance program for low-income patients. The program is funded by a combination of federal and state money and is free to beneficiaries. Children’s Dental Group says on its website that its is one of the largest Denti-Cal providers in California.

The company has 10 clinics in California, eight of them in Southern California. They brought in almost $17 million from Denti-Cal in the first nine months of the year. The clinics brought in $15 million from Denti-Cal last year, according to figures from the California Department of Health Care Services.

Officials are asking any clients of Medi-Cal who believe the dentists did excessive or unnecessary treatments to file a complaint with the Dental Board and with the Medi-Cal Fraud Unit.

Last year, a report from the Federal Department of Health and Human Services found 28 dentists from Children’s Dental Group have questionable billing practices.

“Our concern is certainly that these dentists that have really unusual patterns need to be looked at and scrutinized more thoroughly to ensure that children are getting the care that they need and deserve,” said Meridith Seife, deputy regional director for health and human services in the Office of the Inspector General.

Children’s Dental Group Chief Executive Samuel Gruenbaum denied wrongdoing on the part of his clinics and dentists.

“All the treatments done by the doctors in this organization have been treatments that the kids needed … treatments that were justified by the dental records that are in the charts, and treatments that the families were aware of and consented to,” Gruenbaum said.

The California Department of Health Services says it’s committed to more oversight of dentists who might be overbilling. And the California Dental Board is still investigating the Anaheim office of Children’s Dental.