The series eventually prompted changes to Colorado state law. This is the story that originally aired on May 25, 2004.
DENVER - Three former workers in Colorado dental offices say they were told to buy radios to drown out the cries and screams of children.
The workers came forward after seeing two 9NEWS investigations into the dental clinics.
"When any child started crying, we turned the radios up," said Teenesha Stepney and Naikia Grays who worked at the Children's Dental Clinic in Thornton and the Medicaid Dental Clinic in Aurora.
"We were told to do that so the parents couldn't hear them holler," said Stepney.
Office Manager Annett Gallegos said she was told to buy 14 radios for the clinics.
"If parents knew what was going on, they'd be furious," said Gallegos.
Gallegos resigned as office manager after working in the Thornton Clinic six months.
She says children were put in restraint devices called papoose boards every day because it was easier for the dentist to work on them.
"I did not agree with the practices that they were doing and I resigned," said Gallegos.
All three former workers said if kids were too big to put in a papoose board, assistants were trained to climb on top of the child and hold down their legs and arms.
"If they're kicking their legs and want to get out, one assistant would have to get on top of the child and hold his shoulders down and straddle them," said Stepney.
The three workers also confirmed what many parents have told 9NEWS: that parents were not allowed to stay with their child while the dentist worked on their teeth.
Parents say they were made to wait in the waiting room.
Stepney said, "If parents don't want their children to go back in the clinic alone, they are told to go elsewhere. They were never allowed back."
"I think parents are not allowed to go in the back because if they saw the procedures, you would have known about this a lot sooner than what you know now," said Gallegos.
[The following Colorado dentists sold their ownership in the clinicis in 2007]
Dr. William Mueller of Denver and Drs. Ed and Michael Derose of Pueblo own the clinics.
The Deroses also own three other clinics that cater to children on Medicaid in Colorado.
The five clinics last year (2003) collected more money from taxpayers than any other clinics in the state, more than $13.5 million.
Dr. Mueller will not talk to 9NEWS on camera.
But in a statement to 9NEWS, Mueller wrote that the workers "are all disgruntled employees who were either terminated for cause or resigned."
He also said that "music is commonly used in professional offices to provide a comfortable environment for staff and patients."
Mueller says that the clinics inform and obtain consent from all parents about the management techniques that might be used on their children, including papoose boards.
Mueller says that assistants may "stabilize a patient's feet or abnormal head movements using a technique called 'Active Immobilization.'"
Vicky Wilson signed a consent form saying that dentists might use management techniques and a papoose board on her son, 4-year-old Rand.
But Wilson says she didn't understand Rand might be scared and hurt, because the clinic would not let her stay with him.
"If I would have heard him screaming, I would have gotten up and said, 'Hey wait a minute. Let's not do this,'" said Wilson.
The mom said Rand came out of the dental office crying hysterically and had peed in his pants.
"He was soaking wet from head to toe, like someone had just drenched him with a bucket of water," said Wilson.
"It was his hair, his clothes and he was upset because he said 'Mommy, I peed my pants' because he was crying so badly and they wouldn't let him get up to go to the bathroom."
Rand showed his mother how someone held his throat and head while the dentist worked on him.
Wilson said her son broke out in red bumps all over his face and neck. She took him to Peak Pediatrics to be examined by physicians assistant Randal Williams.
He noted that "Rand has petechial lesions on his neck, face and eyes consistent with being restrained by human hands."
Rand was not the only child hurt by the restraints. 9NEWS obtained police photos of three other children with cuts, scrapes and bruises after trips to the dental clinics.
"Parents, if they were to leave marks like was left on my son, their children would be taken away from them and they would be put in jail," said Wilson.
Dr. Mueller said he is not familiar with Wilson's case. "A child is always allowed to use the restroom if requested," said Mueller.
"However...they have accidents which we treat and clean appropriately while at the same time comforting them in order to avoid child embarrassment."
Mueller said that Rand was most likely hurt as a result of crying.
"No employee in our facility ever has or ever will restrain a child by holding their throat," said Mueller.
"Any attempt to do so by any employee would result in an immediate termination."
The Metro Denver Dental Society responded to the allegations in the 9NEWS story.
"I was shocked and surprised as both a dentist and a parent as far as how those children looked at the end of their dental visits," said Dr. Jeffrey Hurst, DDS, past president of MDDS.
"I've been a dentist for 23 years and we've never experienced anything like that in my office," said Hurst.
MDDS represents 1,400 dentists in the metro Denver area.
Hurst says restraints or papoose boards are designed to be used in the case of a dental emergency or to protect a child with behavior management problems.
"They're usually only used as a last resort," said Hurst.
Hurst said MDDS encourages parents to go back and watch the care being administered to their children.
"We encourage parents to take an active role in the child's dental health, in their care and in their treatment plan," he said.
Hurst thinks it's time to set some guidelines for allowing parents in the treatment room.
Either way, Vicky Wilson says she will never take Rand back to the medicaid dental clinics again.
"I would just like them to never be able to work on another child. Ever. Anywhere." said Wilson.
Dr. Mueller was charged with gross malpractice for over-using papoose boards on children in his clinic in Memphis Tennessee.
But Friday, the Tennessee Dental Board dropped those charges against him.
However, the board voted to reprimand Mueller for false and misleading advertising in his clinic there.
In a letter to 9NEWS, Dr. Mueller's attorney Lela Hollabaugh wrote that, "We are pleased with the result of the hearing before the Tennessee Dental Board."
This story originally aired on May 25, 2004.