Cosmetic Dentistry

There’s a reason that orange juice or any citrus juice will taste bad if you drink if shortly after brushing your teeth.  Most citrus juices combine both bitter and sweet tastes and your mouth can tell the difference. 

Our taste buds can detect five different flavors: sweet, salty, sour, bitter, and umami (aka savory).  Each flavor has a unique shape that matches up to a taste receptor on the tongue with a corresponding shape. Many flavor messages go to the brain when more than one flavor is consumed.

Sodium lauryl sulfate (SLS), a known surfactant found in most toothpastes, works like a soap in cleaning your teeth. It bubbles up and spreads all around to clean every crevice and cranny.  Orange juice has both bitter and sweet flavors and SLS inhibits our ability to taste sweetness, so when you drink orange juice after brushing, you only taste the bitterness.

In addition to inhibiting sweetness, SLS also breaks down phospholipids which tamp down the bitterness from food and drinks.  The bitterness in orange juice is enhanced and you really don’t like the taste of it after that.

We have flavor receptors in our tongue, so when a bitter molecule binds to a bitter receptor, that sends a message to the brain saying that something bitter has been eaten

You could wait until after breakfast to brush your teeth, but orange juice and other citrus juices are acidic and can soften the enamel according to the American Dental Association (ADA).  Brushing with toothpaste containing SLS after juices, can disturb some of the softened enamel.

The good news is that the effects of SLS are short lived, only a matter of a few minutes, so you can brush your teeth, then get dressed or do other time-consuming tasks before eating breakfast and the effects of the toothpaste should be gone.