More adults in Wales have dental problems than in England even though they visit the dentist more often, UK government figures show.
The 2009 adult dental health survey also found one in 10 adults in Wales has no natural teeth.
Wales fares worse than England and Northern Ireland for decay and only 80% of the population is able to eat comfortably because of dental problems.
The assembly government said dental health was improving.
The figures, which offer a snapshot of dental health over the past 10 years in England, Wales and Northern Ireland, were released by the Office for National Statistics and the NHS Information Centre on Wednesday.
Overall, dental health had improved across all three countries.
But the survey showed that a greater percentage of the Welsh population has no natural teeth and higher levels of tooth decay.
One in 10 adults in Wales has no natural teeth. In England the figure is one in 17 and in Northern Ireland it is one in 14.
However, overall, the majority of adults - 71% - had no decay on the crowns of their teeth.
The figure has improved vastly since 1978, when one third of Welsh adults had no natural teeth.
It was the largest ever survey of adult dental health in the three countries. It has taken place every decade since 1968.
More than 11,300 individuals were interviewed and 6,469 adults were examined.
In addition, 80% of people in Wales have the accepted number of teeth required to eat comfortably, compared with 86% in England and 84% in NI.
This was up from 71% in 1978.
The research also found that nearly seven in 10 adults in Wales have regular dental check-ups compared to just under four in 10 in 1978.
In England and Northern Ireland the 2009 figure is about six in 10 adults.
A Welsh Assembly Government spokesperson said the survey showed dental health amongst the population of Wales is improving.
"More people are receiving regular dental check-ups than ever before," said the spokesperson.
"Whilst some of the statistics compare less favourably with England as a whole, or Northern Ireland, the improvement from where we started must be recognised."
The survey also showed that women are twice as likely to suffer extreme anxiety when visiting a dentist compared to men.
Some 66% of adults in managerial and professional households attended regularly in 2009, compared with 55% of those from routine and manual occupation households.
NHS Information Centre chief executive Tim Straughan said: "This survey shows dental health has improved in England, Wales and Northern Ireland and the condition of people's teeth overall has got much better since this survey was first carried out.
"However it does show there is variation in dental health between England, Wales and Northern Ireland, as well as in the percentage of our populations who see a dentist regularly.
"The survey also suggests that more than one in 10 of us are extremely anxious about being in the dentists' chair."