THREE out of four dentists are more likely to leave the National Health Service as a result of the Government's Green Paper on dental reform, according to a survey from Denplan, the UK's leading dental care programme. A mere 3 per cent of dentists say they are now more likely to stay in the NHS.

The survey of 500 dental practitioners shows that in 1989 almost 90 per cent of dentists treated patients on the NHS. This year the figure is 60 per cent and by 1999 is expected to drop to 30 per cent.

Dentists do not necessarily approve of the shrinkage of the NHS. Some 57 per cent said they were unhappy or extremely unhappy about the Government's recommendation to make non-exempt adults pay 100 per cent of their treatment costs. But if the Green Paper recommendations are accepted, private dentistry will continue to expand.

Denplan, owned by Private Patients Plan, pioneered the capitation scheme of payment in 1986 and is the market leader, with 5,200 dentists in its network about some 500,000 patients. Dentists assess the state of a patient's teeth and charge a monthly amount to cover long-term preventative care.

Denplan has five fee categories with discounts for children and other groups. More than 90 per cent of its patients pay between pounds 5 and pounds 15 a month for treatment. Supplementary insurance cover includes pounds 300 per claim for emergency treatment worldwide; pounds 5,000 per claim for treatment resulting from an accident and pounds 50 for every night spent in hospital due to dental treatment.

Bupa and Norwich Union are also rolling out capitation plans and the latest into the field this week is Clinident from Medical insurance Agency.

Clinident claims that it is the first plan to run on a computer software package and can therefore keep costs to a minimum. Unlike some rival plans, there is no deduction for administration charges. Clinident makes its money through the pounds 24 annual insurance fee, which provides payment protection against accident, sickness, redundancy or trauma to teeth.

Monthly payments for treatment are agreed between patient and dentist and are governed by the charges set by the practice concerned. Patients do not have to be dentally fit to join Clinident.

Bupa Dentalcover, which launched pilot programmes in January, has signed up more than 1,000 dentists, some of whom are also Denplan dentists. Its plan works very much like Denplan's with five fee bands.

Norwich Union also launched in January and has so far signed up more than 600 dentists, who could also be in the Denplan or Bupa networks.

It operates differently in that it determines the fee levels, rather than the dentist. It offers three levels of cover and three cost areas depending on the location of the dental practice.

Clinident expects its stand- alone dental plan to appeal particularly to those covered by individual or company private medical insurance (PMI) which does not include dental benefits.

Those not covered by PMI can often qualify for a discount if they join a dental plan provided by the big medical insurers. Denplan patients, for example, receive a 20 per cent discount off medical insurance provided by FPP.