A dentist has been charged with death of a 64 year old patient who flatlined while having 20 teeth extracted.
Dr Rashmi Patel was charged with criminal negligent homicide and tampering with evidence after turning himself in on Tuesday, according report said.
He has denied any wrongdoing.
The patient, 64-year-old Judith Gan, died in hospital on February 17 2014, after undergoing treatment to remove the teeth and insert the implants at Patel's surgery in Enfield, Connecticut.
State dental regulators concluded that Patel failed to adequately respond when Gan's oxygen levels dropped dangerously low.
Gan's death and other incidents prompted the State Dental Commission to suspend the Patel's license in December, pending a review of his practice.
But, the dentist's lawyer Paul Knag said the commission did not revoke Patel's license.
"In the Dental Commission proceeding, multiple expert witnesses testified that Dr. Patel followed the standard of care," he said.
"The state's seeking of criminal charges is contrary to this evidence and inconsistent with the decision of the Commission not to revoke his license."
The commission said in a report that Patel "ignored" signs that Ms Gan, of Ellington, was in distress, including the drop in her oxygen levels, changes in the color of her face and hands and wheezing and gurgling sounds.
It said Patel, also ignored warnings from his dental assistants that Gan was in danger, and the he should not have attempted to perform so many procedures on Ms Gan in one office visit given that her medical history included a heart attack six months before the visit, two strokes within the last two years and medication that could have affected her response to the sedation.
When one of Patel's assistants yelled that Ms Gan was "flatlining," Patel tried to revive her while the assistant called 911.
The patient was rushed to a hospital, where she was pronounced dead.
Patel is also said to have violated care standards in December 2013 when another patient under conscious sedation to have teeth extracted inhaled a piece of gauze, which was designed to protect him from swallowing foreign objects.
The patient began flailing, his blood pressure spiked and he was rushed to a hospital but recovered.
Patel, who posted $25,000 bail, has denied any wrongdoing in his treatment.
A lawyer for Ms Gan's husband has said a lawsuit against the dentist is planned.