Dentists say elite athletes could stand a better chance of winning gold medals if they look after their teeth.
The Oral Health and Performance in Sport conference in London heard that athletes' oral health was often bad and could impair training and performance.
At the pinnacle of elite sport, the difference between winning and losing is tiny, so even marginal improvements can make a crucial difference.
Doctors for Team GB's boxing squad are already trying to improve oral health.
A study, published in the British Journal of Sports Medicine, showed a fifth of athletes said their oral health damaged their training and performance for the Games.
At the conference, dentists said tooth pain could disrupt sleep and training and that inflammation of the gums could affect the rest of the body, impairing performance.
It is not unusual for poor oral health to have wider effects. The NHS says it is linked to type 2 diabetes and heart problems.
A regular floss, a bottle of mouthwash and good brushing technique are not going to transform a weekend jogger into an Olympian.
However, Prof Ian Needleman, director of the International Centre for Evidence-Based Oral Health at University College London, says there could be an impact in elite sport.
He told the BBC: "It's the accumulation of marginal gains, where the difference between elite athletes at the very top is small. Then oral health, amongst other aspects, could make a difference.
"The research we did at London 2012 found a large proportion of young athletes, fantastically well tuned physically, had really poor oral health.
"Quite a high proportion reported an impact on their training and performance so it's clearly an issue for them."
Doctors with GB Boxing are already trying to improve dental hygiene after noticing poor oral health had affected training.
Dr Mike Loosemore, who has worked with the GB boxing team for 17 years and is a consultant at the English Institute of Sport, told the BBC: "I've become aware over the years that dental problems have been interfering with training. It stops them getting that little bit fitter and may have a consequence when they get into the ring and box."
He says things are now improving after regular dental checks were introduced, even if they are not always popular with the boxers.
"They don't like going to the dentist. They'd much rather be training. However, it has made a difference to their teeth and they are spending less time away from their training, and that will make them a better boxer.
"They may not appreciate it now, but hopefully they'll appreciate when they've got a gold medal round their neck in Rio [at the 2016 Olympics]."