There is an "unacceptable and growing chasm" between good and poor dental health in the UK, dentists warn.
Greater focus is needed on prevention, especially in children living in deprived areas, a report from the British Dental Association (BDA), says.
Older people and those with disabilities are also particularly at risk from poor oral health and need more attention, it found.
The Department of Health said oral health is improving.
The BDA called for a more integrated approach from health and social care to tackle rising inequalities in dental problems.
Among children, the effect of deprivation on teeth is particularly marked, they said.
In the poorest areas, 60% of five year-olds and 70% of eight year-olds have obvious signs of decay in their milk teeth.
This compares with 40% of five year-olds and 55% of eight year-olds in more affluent areas.
The report also highlights a seven-fold difference in dental health between the best and worst health trusts in England.
Alcohol and tobacco are also key factors in oral health inequalities, the BDA added, and dentists should be more involved in counselling patients, helping them to quit.
And it also called for targeted fluoridation to reduce the risk of tooth decay.
Professor Damien Walmsley, scientific adviser to the BDA, said: "There has been a significant improvement in the nation's overall oral health over the last 30 years, but despite that we still see a huge disparity that is all-too-often related to social deprivation.
"It is completely unacceptable that in Britain, in 2009, such a wide gap should exist.
"Much good work to address this problem has begun, and this report commends a number of schemes such as Brushing for Life and Sure Start that are starting to make a difference.
"However, a great deal of work remains to be done and it is vital dentists are supported in doing it."
Chief Dental Officer for England, Dr Barry Cockcroft, said: "We agree with the British Dental Association that it is vital to do everything possible to reduce oral health inequalities.
"Our children have among the lowest rates of tooth decay anywhere in the world.
"We have already published the world's first evidence based guide to prevention, and it has been sent to every single dentist in practice in England."