A world-first vaccine to fight severe gum disease is to be trialled in Australia, which is good news if you kissed the wrong person in high school.
The University of Melbourne collaboration is tackling a condition called periodontitis that affects a lot of Australians -- one in three to be exact, and the number increases to half of all people over 65.
It's a bacterial infection that can result in the loss of a tooth, but it's recently been discovered to have strong links to pancreatic cancer, diabetes and dementia.
And what's this got to do with the ill-advised smooch you had with your Year 10 crush? The university's Oral Health Cooperative Research Centre chief executive Eric Reynolds told HuffPost Australia it was to do with bacteria.
"I always tell my dental students to screen their potential partners carefully because when you kiss, you swap bacteria," Reynolds said.
"Over the last five years or so, we've come to know that some bacteria is quite beneficial but other bacteria can be bad."
Like the bacteria that causes severe gum disease.
He said a vaccine for periodontitis was a big jump from today's commonplace treatment -- antibiotics and removing the affected area (sometimes with surgery).
"I think the major evidence that made me think that a vaccine may work was when we realised there were specific bacteria associated with the disease.
"Bacteria in dental plaque that grows in the pocket between the gum tissue and the tooth root. Some of the bacteria growing there is beneficial, it stops disease-causing bacteria from colonising.
"The bad bacteria that causes periodontitis though, it actually changes the balance of the immune system, it subverts it so that the immune system actually destroys the tissue around the tooth.
"I used to think that was a pretty severe way for the body to get rid of the bacteria, but then we learned more about how nasty this particular bacteria could be. It can pass into the bloodstream and is linked to cancers and cardiovascular conditions. It can end up inside cells lining the arteries or pancreas where it releases carcinogens.
"So for the body to choose between losing a tooth or keeping the bacteria, it's not a bad choice."
The vaccine is designed to work in people who already have the condition and it works in two ways -- it lets the body recognise and attack the actual bacteria but it also switches the body's immune system back to normal, so it stops attacking tissue around the infection.
"Our results are very promising and with our partners CSL, we have everything in place to start trials in 2018."