A Salt Lake dentist with a history of unprofessional conduct has been accused of carelessly prescribing drugs, submitting forged insurance claims and administering nitrous oxide without a permit, a petition says.

Dr. Gary Holmes Weaver has had three petitions issued against him since 1978 by the state Division of Occupational and Professional Licensing and was suspended from practice for 11 months. This most recent round of allegations occurred while he was on probation, according to an amended petition issued April 29.The division accuses Weaver of overprescribing pain medication to drug-addicted patients. One of the addicted patients forged a prescription on one of Weaver's prescription forms, but the pharmacy noticed the forgery and rejected it, the petition said.

Weaver was aware of the forgery attempt, the petition said, but wrote the patient another prescription and told him not to fill it at the pharmacy that caught the forgery.

From January to October last year, Weaver submitted forged and back-dated insurance claims, the petition said. He pleaded guilty in 2nd District Court last month to two felony forgery charges.

Weaver also billed insurance companies for administering nitrous oxide, which he does not have a permit to administer, the petition said. On one occasion, the petition said, Weaver administered the gas to a patient for two hours without performing any dental work.

Weaver closed his dental practice last October, the petition said, without notifying 57 nursing home patients he provided dental care for.

The division charges Weaver with six counts of unprofessional conduct and has requested revocation, suspension or other sanctions against his license.