Sleeping with the mouth open can be as damaging to teeth as having a fizzy drink before bed, finds a new study.
The reason behind it, is that breathing through the mouth dries out the protective effect of saliva, which has a natural ability to kill the bacteria in the mouth that produce acid.
As acid levels rise through the night, tooth erosion and decay can begin. Tooth decay in mouth in such cases often occurs at the back of the mouth and tends to get drier than the front.
‘Sleeping with the mouth open reduces the neutral level of 7.7 to a mildly acidic average a pH of 6.6, increasing the chance for tooth decay.’
Patients with asthma and obstructive sleep apnoea are more likely to breathe through the mouth at night.
Under normal conditions, the pH level in the mouth - the measure of acidity or alkalinity - is a neutral level of 7.7.
But sleeping with the mouth open reduced this to a mildly acidic average a pH of 6.6.
In some people, acidity levels rose as high as 3.6 which is high enough to erode tooth enamel and akin to having a glass of orange juice or a can of fizzy drink before bed.
Men are most likely to be affected, as research has shown nearly a third breathe through their mouths while asleep, compared to just five percent of women.
Ms Choi, a PhD student, said, "This study is the first to continuously monitor intra-oral pH changes in healthy individuals over several days. Our findings support the idea that mouth-breathing may indeed be a causal factor for dental diseases such as enamel erosion and caries."