Why? Simple: It’s the spit – or, rather, a lack of it, since we produce less while we sleep. During the day, saliva is a perpetual bath for your teeth, helping wash away food particles and the oral microbes that make up dental biofilm (plaque). When your mouth is dry, it’s bacterial partytime, which is why those with chronic dry mouth tend to have chronic halitosis, too. The stink comes courtesy of the microbes’ metabolic waste.
As the proverbial They say, it’s an ill bird that fouls its own nest.
But we digress…
Now since the lighter saliva flow leaves microbes free to do their microbial thing, you might think this means more biofilm builds up on your teeth while you sleep. In fact, research published last month in Acta Odontologica Scadinavica shows just the opposite.
For the study, researchers analyzed biofilm collected from healthy individuals at 12 hour intervals. Although, naturally, bacterial levels and composition varied widely among individuals, the authors found that both bacterial count and volume were highest during waking hours – “firm evidence,” they wrote, “that initial biofilm formation decreases during the night.”
Why? “The data,” suggest the authors, “may reflect differences in the availability of salivary nutrients.”** In other words, partytime isn’t feeding time. That, of course, happens while we’re awake – until we put a temporary halt to their fun by brushing and flossing.
Doing the same before turning in each night can go a long way toward taming morning breath, as well – along with limiting alcohol consumption and not smoking.
** There are, of course, many other variables, such as the state of the autonomic nervous system, hormone function, alkalai/acidosis cycles, dental restorations present and more – all, however, beyond the scope of the present study.
Image by joshunter, via Flickr