It is hard to come across a commercial which does not depict the classic, wave-shaped blob of toothpaste covering the entire brush. But is that really the right amount people should be using?

Dentists point out that a pea-sized amount of fluoride toothpaste should be sufficient for one session of brushing. Furthermore, children under the age of three could use an even smaller amount, around the size of a grain of rice.

The message is that more paste does not mean cleaner teeth. As it turns out, a lot of us have been overdoing it. Just take a look at the findings of a new government survey — 40 percent of kids between the ages of 3 and 6 were found to be using a brush that was "full" or "half-full" of toothpaste.

"Fluoride is a wonderful benefit but it needs to be used carefully," said Dr. Mary Hayes, a pediatric dentist based in Chicago. The naturally-occurring mineral is said to play a significant role in reducing cavities.

However, being exposed to too much fluoride when permanent teeth are being formed can lead to dental fluorosis i.e. a condition characterized by discoloration or spots on the enamel. One of the issues with kids' toothpaste is that it tastes sweet, which means some may feel tempted to ingest it. 

"You don’t want them eating it like food. We want the parent to be in charge of the toothbrush and the toothpaste," Dr. Hayes said, recommending that parents keep an eye out even when children of this age group push for independence.

While this risk is limited to younger age groups, adults can also experience downsides by using excess toothpaste — that is, besides your money going down the drain if you happen to use an expensive brand.

You should be taking two minutes to brush your teeth and also make sure to move in various directions to get to every part of your mouth. But a large blob of paste will produce too much foam, making it hard to brush correctly and to do so for the right amount of time.

"In fact, we spit most of the extra toothpaste into the sink without it ever touching our teeth. The excess foam fills our mouth and can also make us stop brushing sooner than we should," writes Dr. Christopher Chamberlin, a dentist based in Boulder, Colorado.

Another tip is to not brush too hard as some falsely think this could help clean teeth in lesser time. Rather, too much friction can wear away the teeth and hurt your gums. If you find that you have to replace your toothbrush every two or three months, it is a good sign that you may be brushing too hard.