People with bad teeth can no longer just blame it on too many sweets or too few visits to the dentist as children, researchers say.
It's never too late to start looking after your dental health
A team from Newcastle University say it is an unhealthy adult lifestyle which causes poor oral health in later years.
The study, in the Journal of Dental Research, looked at data on over 300 people.
It found the link between family background and dental problems
diminished with age.
The study, which used data from the Thousand Families Study, which has collected information on a cross-section of children born in Newcastle upon Tyne in 1947, found the link eventually became virtually insignificant.
The team studied childhood information taken from 337 volunteers, together with more recent data on adult health and lifestyle collected at age 50.
Researchers looked at the number of teeth people had lost over time, as tooth decay and gum disease are both cumulative and ultimately result in tooth loss.
It was found that the more cigarettes a person smoked, the more teeth he or she was likely to lose.
Previous research has shown that smoking restricts the blood flow in the gums, leading to disease and tooth loss.
Poor social circumstances in adult life are also associated with infrequent tooth brushing and irregular dental attendance, the researchers said.
The researchers are calling for more to be done to improve the dental health of adults as well as children, potentially including making smoking cessation advice part of dental care.
Dr Mark Pearce, the lead researcher and director of the Thousand Families Study, said: "Damage to teeth and gums happens over a long period of time and is irreversible.
"These findings demonstrate that it is just as important for adults to look after their teeth and gums as children, and that good oral healthcare habits shouldn't stop when people leave their family home."
He said: "Even if people aren't used to following a tooth-care regime, it's never too late for them to start .
"They can't turn the clock back but they can increase their chances of maintaining a good set of teeth into their old age - something which is very significant when you consider life expectancy is increasing all the time."
Professor Jimmy Steele, of Newcastle University's School of Dental Sciences, who also worked on the study, said: "Even people who look after their teeth when they are children may slip into bad habits when they leave home and indulge in an unhealthy lifestyle as young adults.
"It's common for chocolate bars to be substituted for meals, or for regular teeth brushing to stop.
"In fact, studies show that men aged 20 to 30 are the worst at looking after their oral health."
A spokesperson for the British Dental Association said: "Looking after your teeth is important regardless of how old you are.
"A simple routine of brushing your teeth twice a day with a fluoride toothpaste can keep your mouth healthy, but you shouldn't ignore the other factors which can have an effect on your oral health.
"Some food and drink can stain your teeth, so try to avoid, or at least reduce, things like coffee, red wine and curries.
"Smoking not only affects how your teeth look, it can also cause gum disease and even mouth cancer. Giving up may be tough, but it's certainly worth it in the long run."