The mother of a two-year-old boy who died while undergoing a root canal is suing the dentist over what the family described as “gross medical negligence”.

Zion Gastelum had been seen by the dentists only twice before they said the toddler needed multiple pulpotomies, which are baby root canals.

The procedure, meant only for cases in which the nerve has been damaged, requires general anaesthesia.

Although it seemed drastic, Zion’s parents trusted that privately held US dental company Kool Smiles had his best interests in mind and the Arizona boy’s mother Veronica Gastelum took him to get the procedure done on December 20, 2017.

According to a wrongful death lawsuit filed by Zion’s parents, Ms Gastelum was the first to notice something amiss.

The complaint details how she arrived at the procedure room and found Zion hooked up to a heart rate monitor that was showing no pulse — which the staff reportedly shrugged off as a faulty machine.

After noticing his chest was not rising, Ms Gastelum suggested he was not breathing.

It was not until then, she said, that nurses sprang into action and called emergency services.

Zion was rushed to an emergency room where he was pronounced dead shortly after arriving.

His official cause of death was severe hypoxic-ischemic encephalopathy or a lack of oxygen to the brain.

The Gastelums claim their son’s death was the result of “gross medical negligence”.

‘Knowingly submitted false claims’

But although on the surface it may seem like a singular tragedy, earlier legal documents suggest trouble beforehand.

In January 2018, Kool Smiles, which specifically caters to low-income families, agreed to pay nearly $24 million to settle a false claims lawsuit brought by the US Justice Department.

In the complaint, the Justice Department alleges Kool Smiles “knowingly submitted false claims” to Medicaid for “medically unnecessary pulpotomies”, among other procedures.

It goes on to claim that the company bribed doctors not only to perform many of these procedures, but also to do so quickly.

The Gastelums’ lawsuit quotes US Attorney John H. Durham for the District of Connecticut, who touched on the cruelty of Kool Smiles’s alleged tactics in the Justice Department complaint.

“The allegations in these cases are particularly egregious because they involved medically unnecessary dental services performed on children,” Mr Durham said.

“Exploiting needy children for financial gain is inexcusable.”

Eager to fight

In the lawsuit, the Gastelums’ attorneys write there were “far less expensive” and “safer” methods to treat Zion’s cavities — including $25 silver diamine fluoride.

But because they chose to put Zion at risk, his family is now fighting to make sure it did not happen again to someone else.

In response to Yahoo Lifestyle’s request for comment on Zion’s case, Kool Smiles said “the doctors and staff of the Yuma Kool Smiles office continue to extend their sincere, heartfelt sympathy to the Gastelum family”.

“Since 2007, the office has safely and compassionately provided needed dental care to thousands of families. Respectfully, we have no further comment as this matter is pending litigation,” the statement continued.

Speaking with Yahoo Lifestyle, an attorney for the Gastelum family said although they are still in mourning, they are eager to fight for change.

“We look forward to having the complaint and these issues resolved in court,” Scott Eldredge said.