What does toothpaste do when I’m brushing? Why is it better than not using toothpaste?



What does toothpaste do when I’m brushing? Why is it better than not using toothpaste?

In: Chemistry

You wouldn’t wash your hands without soup and say you washed your hands, would ya?

Brushing alone gets debris off. With toothpaste, it gets the bacteria off. It binds to (and sometimes kills) the bacteria, so you spit it out. Fluoride strengthens enamel, too, by giving it protection against the acidity of bacteria, which erodes teeth and forms cavities.

The bacteria in your mouth form a thin, sticky film (“plaque”) that covers all of your mouth if you haven’t brushed recently. Over time, that film becomes stickier, so any you miss becomes harder and harder to remove. Eventually it picks up minerals from your saliva and hardens into a rock-like material (“calculus” or “tartar”), which is what your dentist scrapes off when you go in for a cleaning.

Brushes are soft, and can only remove things that aren’t sticking to your teeth very well. That means little bits of food debris and the very early stages of this film. Toothpaste contains abrasives that can scrape off some of the stickier medium stages of plaque as well, which reduces the amount that eventually hardens into tartar (which is too firmly stuck to be removed by brushing). Most toothpastes also contain small amounts of fluoride, which gets built into the crystal structure of the surface of your teeth in a way that makes them decay more slowly.

It’s like soap with some added benefits for your mouth.

It has things that reduce surface tension and make bacteria less able to cling to your teeth, just like how soap works.

It has fluoride that helps keep your enamel tough. It can’t fix holes or cavities, but can help prevent them from worsening.

It has abrasives, things that give it that slightly scratchy texture. This aids your toothbrush in scraping plaques and stuff off your teeth. Some toothpaste contains more/coarser abrasives than others. You want a balance in this, because too abrasive can damage your teeth.

It can also contain extra things for specialized toothpastes.

Some might have antibiotics or such to be more effective at killing bacteria.

Some contain potassium nitrate. This is found in toothpastes that reduce sensitivity.

Together, these things greatly increase the effectiveness of brushing.