A 57-year-old Manchester dentist has been indicted on 189 counts of Medicaid fraud.

The dentist, Dr. Nicholas Marshall, is alleged to have made false claims to the New Hampshire Medicaid office for procedures performed over the past five years, including oral exams, X-rays, tooth extractions and orthopedic treatment.

According to the indictments, the claims were either unjustified based on treatment records or had already been paid for through the program. In the latter case, Marshall is effectively accused of billing the Medicaid office for individual services he was already being reimbursed for under a lump-sum treatment plan.

The indictments were released Friday and dated Dec. 20. Each charge carries a possible 3½- to 7-year prison sentence, meaning Marshall technically faces between 661½ and 1,323 years of incarceration.

A resident of Webster, Marshall received his medical license in 1985 and still practices out of his office on Hanover Street, said Jim Moir, his attorney. None of the charges against him have anything to do with the level of care he has provided his patients, Moir said.

Moir said he had just learned of the indictments and was unsure of exactly what the attorney general’s office was basing its accusations on. He noted that Medicaid regulations are extremely complicated and change regularly, meaning the issue could come down to a basic misunderstanding.

A spokeswoman for the state Department of Health and Human Services, from which the Medicaid office operates, declined to comment. But Sarah Blodgett, an assistant attorney general in the Department of Justice’s Medicaid Fraud Control Unit, said providers voluntarily enroll in the program and agree when they do to educate themselves and stay up to date on its regulations.

Marshall is scheduled for arraignment Jan. 15.