Could simply taking care of your teeth by brushing and flossing every day help protect against oral and throat cancer?

A new study suggests there could be a link between poor dental health and infection with a key cancer-causing virus.

Research published this week found that people who poor oral health, including gum disease and lost teeth, were more likely to be have oral infections of HPV, or human papillomavirus.

Research in the U.S. has shown that about 7 per cent of adults have oral HPV. The virus has been shown to cause about 40 to 80 per cent of cancers in the area at the back of the mouth called the oropharynx. There are dozens of strains of HPV, with some high-risk types linked to cancer, and other low-risk types causing tumours or warts in the mouth.

Actor Michael Douglas made headlines earlier this year when he said his throat cancer had been caused by oral sex, although his publicist later said his comments had been misinterpreted.

This study did not look at why poor oral health might be linked to HPV infection. But the researchers note that HPV viruses needs small wounds in the mouth or throat such as ulcers, gum inflammation or disruption of mucous membrane, that would allow infection to enter the bloodstream. Further research is needed to understand the relationship, the researchers noted.

For the study, which appears in Cancer Prevention Research, a journal of the American Association for Cancer Research, researchers looked at more than 3,400 participants in a U.S. health and nutrition survey called NHANES.

Those participants who self-reported that they had poor oral health had a 56 per cent higher prevalence of oral HPV infection. Those who had gum disease had a 51 per cent higher prevalence of oral HPV infection, while those with dental problems, such as lost teeth, had a 28 per cent higher prevalence.

This study looked only at poor oral hygiene and HPV infection, not oral cancer. But Dr. Thanh Cong Bui, from the School of Public Health at the University of Texas Health Sciences Center in Houston, says this is the first study to look at poor oral health as an independent risk factor for HPV infection.

"The good news,” he said, “is this risk factor is modifiable. By maintaining good oral hygiene and good oral health, one can prevent HPV infection and subsequent HPV-related cancers."

The researchers also found that being male, smoking cigarettes, and oral sex habits increased the likelihood of oral HPV infection.

But they said they found that people with poor self-rated oral hygiene were still more likely to have an HPV infection, even when they accounted for smoking or had multiple oral sex partners.

Bui added that while more research is needed to confirm the relationship between oral health and HPV infection, everyone should take care of their teeth and gums for a variety of other health benefits.

"Oral hygiene is fundamental for oral health, so good oral hygiene practices should become a personal habit,” he said.