Welsh Lib Dems claim wait for new NHS dental patients too long
Only 37% of dentists in Wales are accepting new NHS patients, according to the Welsh Liberal Democrats.
The party also criticises waiting lists for new patients wanting a dentist, which was six years at one practice.
The British Dental Association said ministers needed to give more direction to health boards over dental spending.
The Welsh government said there had been improvements but recognised access to NHS dentists was "difficult in some areas".
The Welsh Lib Dems said their research showed almost two thirds, 63%, of dentists which accept NHS patients have a waiting list.
Of these, 65% were for more than two months, while once practice had a waiting list of six years.
The research found more than half of dentists, 55%, of dental practices reported an increase in missed appointments in the last year, costing both time and money.
And more than half of dentists, 53%, reported problems with the way the current dental contract operates, with 31% believing the contract needed to change.
Welsh Lib Dems leader Kirsty Williams said: "Although the new dental contract was supposed to improve access to NHS dentists for all, the worrying truth is that NHS dentistry in Wales is still far from a universal public service.
"I believe that dentistry in Wales has been overlooked by the Welsh government in recent years and the findings of our survey confirm that there are still considerable problems facing the service."
The British Dental Association (BDA) said it was a "valuable report".
BDA director in Wales Stuart Geddes said: "If a patient does not go to an appointment, not only is the dentist's time affected but it also affects other people's ability to see the dentist.
"The reason why dentists are not able to have more NHS patients is because the local health boards are simply not commissioning the services.
"They have funding available but tend to hold it back to the end of the year before they spend it. It ends up either going to offset another deficit or back to the Welsh government.
"The Welsh government is working on an oral health plan but it needs to give more direction to health boards on how they spend their money, and hopefully it will do that once the plan is approved by the minister."
The Welsh government said access to an NHS dentist had improved in recent years, particularly in areas which had some of the greatest difficulties in the past.
A spokesperson said: "The Adult Dental Health Survey published in 2011 reported that in 1998, 59% of adults in Wales said they regularly attended the dentist.
"By 2009 this had risen to 69%. In addition, of those who had tried to make an NHS appointment in the previous three years, 93% had been successful.
"In terms of changes to the dental contract, the Welsh government has already carried out a review and since April 2011 has been running pilot schemes which test new ways of working and remuneration which do not rely on the current contractual arrangements."
Those pilots are due to run until April 2013.
- The Welsh Lib Dems said they conducted their survey in late 2011, writing to all 450 dental practices in Wales, whether they work in private, NHS or mixed practices. Nearly half responded.