You need to brush your teeth before you go to bed at night (or whenever you do most of your sleeping) to remove food debris and lower the amount of bacteria in your mouth before sleep.
When you sleep, you’re not drinking water or consuming food, which can allow bacteria to thrive and build up plaque.
Plaque, a sticky film that develops on your teeth when bacteria interact with sugars and starches, poses a risk to your tooth enamel. If not addressed, this sticky substance can harden into tartar, which acts as a barrier against harmful plaque accumulation overnight.
When left to build up, plaque can also cause gingivitis or severe periodontal (gum) disease. When it becomes tartar, the bacteria can cause bad breath (halitosis) and stain/discolor your teeth.