New data has revealed a "decade of inertia in access to dentistry" as the latest figures show a drop in the number of people seen by an NHS dentist, a leading dental surgeon has said.
Professor Nigel Hunt, dean of the Faculty of Dental Surgery at the Royal College of Surgeons, also said it is "appalling" that tooth decay remains the most common reason why five-to-nine-year-olds are admitted to hospital.
The Health and Social Care Information Centre (HSCIC) said its latest figures show there has been a "real reduction in the number of patients seen by an NHS dentist".
They show the number of adult patients seen in the two-year period leading up to April fell by 0.3% to 30.08 million.
Adults are advised to visit the dentist between every three months and two years but the National Institute for Health and Care Excellence (Nice) recommends that the longest time between appointments for children is 12 months.
HSCIC figures show the number of children seen by an NHS dentist in the year leading up to March 31 was 6.9 million, representing just 60% of the child population.
London was the only region where the number of patients seen by an NHS dentist increased.
The South of England had the greatest number of patients seen in the 24 months up to the end of June, with 7.3 million patients seen - a 37.2% share of all patients in England, which it said may be in part because the South has the greatest success rate in achieving a dental appointment.
The Royal College of Surgeons said the nation's poor dental record was a combination of patient complacency with regard to looking after their teeth along with access to dental appointments, both of which need to be addressed by the Government.
Prof Hunt said: "This data reveals a decade of inertia in access to dentistry. In the last two years approximately 50% of adults and almost a third of children haven't seen a dentist. Routine visits to the dentist are vital to maintaining good oral health.
"It's appalling that tooth decay remains the most common reason why five-to-nine-year-olds are admitted to hospital; in some cases for multiple tooth extractions under general anaesthetic - despite tooth decay being almost entirely preventable.
"Visiting the dentist regularly is crucial in providing rapid diagnosis and treatment to prevent both children and adults from being hospitalised due to tooth decay.
"The new Government needs to urgently review why access is not improving and launch a national campaign to stress the importance of seeing a dentist."
HSCIC figures show that the number of permanent fillings and sealant restorations in children increased by 0.1%, but other procedures such as teeth extractions and root canal therapy went down.
It also showed that nearly 24,000 dentists performed NHS work during 2014/15, up by 224 or 0.9% on 2013/14 and 3,787 (18.8%) more than 2006/07.
The increase in the percentage of female dentists continued, rising to 47.1%, from 38.8% in 2006/07.
Sara Hurley, chief dental officer at NHS England, said: "NHS England is pleased to see access to an NHS dentist continues to improve.
"The significant increase in treatment courses, including the provision of fluoride varnish, underlines that the message that 'prevention is better than cure' is getting through.
"This is encouraging and means that as a nation our oral health should continue to improve as we work across the whole of the health service to improve understanding.
"The slight decrease in the number of extractions in children is, of course, widely welcomed.
"In England, young people have the highest consumption of sugary soft drinks across Europe, which is why the Five Year Forward View makes it clear that we all need to get serious about prevention."
Richard Lloyd, executive director of Which?, said: "Our research shows just how difficult it is for patients to get an NHS dental appointment as information about availability doesn't reflect reality.
"The regulator must ensure the existing rules are put into practice, so people can easily find an NHS dentist."