THE body responsible for policing dentists has not recorded reprimands against a dentist who badly burnt a patient's face during surgery, despite upholding a complaint against the dentist.

The case has led the Minister for Health to demand a written explanation from the Dental Council of NSW, after the Herald detailed a string of concerns about the appropriateness of the council's rulings.

Arthur Mills, a fellow of the Royal Australasian College of Dental Surgeons, is accused of causing serious burns to the faces of two patients and superficial burns to another after a drill he was using overheated.

At least one of the incidents was referred to the Dental Council, which upheld the complaint about the burning.

It makes these findings in only 2 per cent of cases but still recorded no reprimands on his registration. He practises with no warning to the public.

In a separate part of the same complaint the council ruled that nerve damage sustained by the victim, Lanai Mooney, 23, of Orange, was a ''statistical complication'' and not negligence.

There was no ruling on costs but the council noted that Dr Mills had offered to pay her medical expenses. It took hours of plastic surgery and specialist nerve treatment to correct the damage to Ms Mooney's face.

She took time off work because she was embarrassed by her injuries. The repairs to her face cost about $15,000.

''I was extremely angry, particularly when I heard from other people this had happened before,'' she said. ''I was the third person and there was no warning.''

The hospital where the surgery took place - Dudley Private

Hospital in Orange - admitted the dentist had burnt the faces of three patients in a year and it had investigated the incidents.

A report prepared by the hospital's chief executive, Steven Rajcany, said Dr Mills ''acknowledged that the most plausible reason for the drills overheating was due to prolonged … use and lateral movement in the case of severely impacted teeth … Based on the reports and the types of burns, surgical technique not equipment fault was the likely cause.''

Neither the hospital nor the council responded to questions from the Herald. Dr Mills declined a request for an interview.

The opposition spokesman on health, Andrew McDonald, said the council should operate under the same guidelines as the body that regulated doctors. ''There appears to be quite a discrepancy,'' he said.

This case comes after the Herald revealed that the council had been forwarding legal waivers to patients on behalf of dentists, indemnifying the dentists against legal action over negligence.

The Minister for Health, Jillian Skinner, has announced an inquiry but it is yet to report its findings.