LOS ANGELES --- An expected week-long airing into allegations that a well-known Bakersfield dentist was grossly negligent in treating patients opened here Monday with a former dental assistant testifying she performed procedures she shouldn't have with his knowledge and under his direction.

Dr. Robert Tupac faces a long list of accusations filed by the state Attorney General's office on behalf of the Dental Board of California. They include not developing appropriate treatment plans, using wrong-size implants and poorly positioning them, allowing dental assistants to do work outside the scope of their licenses, and altering patient records.

Tupac has previously declined to discuss the case with The Californian. His attorney, Jason Friedman of Long Beach, on Monday also chose not to comment as the arguments will unfold this week.

In a trial-like administrative hearing in downtown Los Angeles presided over by an administrative law judge, a deputy attorney general began calling witnesses to bolster her case Monday. Two made it to the stand.

Only one finished testifying, a former registered dental assistant who worked for Tupac in 2004 and 2005 after having worked for 12 years in the Bakersfield office of a dentist who will be a star witness for the Attorney General's office: Robert Reed.

Former dental assistant Deidre Williams said she performed a host of procedures outside the scope of her credentials with the permission of Tupac, including adjusting devices, removing surgery sutures, taking out an implant and cementing temporary crowns.

In one case when Tupac was not in the office and a patient needed a problematic implant removed, Tupac directed her to send the man to another dental office for anesthesia and have him come back. Then, Williams said, Tupac walked her through removing the implant over the telephone.

Under cross examination, though, Williams conceded she had performed more than five of what she at some point learned were non-allowable procedures while working for Reed. She stressed, however, that most were under Reed's supervision.

Williams testified that she only really began investigating what her credentialing allowed after she left Tupac's office.

Williams admitted that she was not comfortable with the situation. But when Deputy Attorney General Morgan Malek asked her if she ever told Tupac she felt uncomfortable, Williams said she didn't feel she could approach him based on how he talked about past employees.

"I felt that my job would be in jeopardy if I spoke up," Williams said.

Williams also revealed that when he let her go, Tupac offered her a separation agreement that would preclude her from disparaging the dentist and other office employees and he'd pay her $3,000.

Under direct questioning, she said she refused to sign it because she was uncomfortable with some of Tupac's practices and didn't want to be under what her attorney characterized as a gag order.

But when Malek tried to explore more deeply what made her uncomfortable, Tupac's attorney, Friedman, successfully argued to the administrative law judge that it was irrelevant given it was a document never signed and wasn't directly related to the care of the two patients at the heart of the dental board complaint.

A couple of times Friedman had Williams acknowledge that she never filed a complaint with the dental board.

"I knew someone else would make a complaint because I knew people were making complaints," she countered. "I knew this day would come."

Williams said she was testifying "for the integrity" of the health and welfare of Tupac's patients.

After Williams finished testifying, former patient Sheila Rios began telling of her experience under Tupac's care, which, based on the attorney general accusation, promises to be difficult to hear.

Rios only had a few minutes on the stand before the hearing adjourned for the day. But she is expected to testify about what the accusation says was the unnecessary removal of some of her teeth; the use of implants that were too big and ill-positioned; bone destruction and other problems that resulted in an altered facial appearance and the need for several reparative surgeries.

Rios testified Monday that she was told her implants would be put in under general anesthesia; the complaint says Tupac used local anesthesia and she endured pain for eight hours in the dental chair.

"She was screaming and crying throughout the procedure," Malek said in her opening statement.

Rios is expected to resume testimony Tuesday.

The hearing is anticipated to last all week. Reed, who filled in for Tupac when Tupac was on medical leave and ended up filing a complaint with the dental board, is also expected on the stand Tuesday.