KEENE — A children’s dentist known as “Dr. Wully” is being accused of overusing nitrous oxide, hurting his patients by putting them in restraining devices, and performing unnecessary dental work.

Blake Wullbrandt, who has an office in Keene and also serves patients in Peterborough, Claremont, and Brattleboro, Vt., is now facing a disciplinary hearing in November before the New Hampshire Board of Dental Examiners.

According to the letter to board sent to Wullbrandt, it was first alerted to the problems in March when it learned he was being investigated by the New Hampshire Department of Justice’s Medicaid Fraud Control Unit. A short time later, the board heard from a former employee about the restraints, nitrous oxide, and unnecessary dental work, the letter states.

The employee told the board that Wullbrandt was physically and mentally harming his patients through the use of restraints and rough treatment, and did not get clear consent before using the restraints.

The allegations go back to 2005 and include numerous patients, according to the letter. Wullbrandt regularly used laughing gas on two patients without specific reason for doing so, according to the letter.

He also used papoose boards and other restraints on several different patients, causing them harm, according to the letter. He is also alleged to have performed surgery using nitrous oxide and local anesthesia as the patients yelled and moved around, showing signs there were not properly anesthetized, the letter states. The Board’s letter states he also performed too many procedures on patients during their visits and that some of these procedures were unnecessary.

In 2017, Wullbrandt had his license suspended for one year by the board as part of a settlement agreement. According to state records, Wullbrandt admitted that he was impaired when he performed a dental procedure on a patient in 2015. This incident led to the patient being injured and requiring a root canal to fix the damage Wullbrandt caused, according to the settlement.

According to the settlement agreement, Wullbrandt told his staff he would go into rehab.

The agreement states that Wullbrandt began drinking again in 2017, and was stopped by his staff in July 2017 from practicing while impaired again. His conduct was reported, resulting in the suspension, according to the records.

The new hearing is set for Nov. 8 in Concord.