Patients of Community First for Treatment Ltd, in Eastfield Road, were left stunned last May when they arrived for treatment only to discover a note on the door saying the practice had been closed until further notice due to “unforeseen circumstances”.

Yesterday, the UK dental regulator, the General Dental Council (GDC), successfully prosecuted the company, which also had a practice in West Boston, for the illegal business of dentistry on two occasions in the last two years.

Community First for Treatment Ltd was convicted in its absence of the two offences at Peterborough Magistrates’ Court yesterday.

A GDC spokesman said: “As Community First for Treatment was receiving payment for dental work when the majority of its directors were not GDC-registered dentists or dental care professionals, it was committing a criminal offence under the Dentists Act.”

Community First for Treatment Ltd was fined £1,000 (£500 per offence) and ordered to pay a contribution of £3,000 to the GDC’s costs.

The practice opened amid fanfare in September 2006 claiming it could benefit up to 10,000 patients in the city.

Although it was run privately, it was hailed an affordable option after bosses said fees would be significantly less than those charged by other private surgeries, or even the NHS in some instances.

However, its shock closure last May left many patients in the lurch, including Leonard Bruce (75), a retired marine sergeant.

Mr Bruce, of Alwalton, near Peterborough, had spent nine hours in the dentist’s chair in preparation for a bridge replacement costing £1,750, about a third of the cost of work carried out by some other British surgeries.

He said he was left with a mouthful of broken stumps and ground down teeth.