Which came first, the chicken or the egg? You might think about this rhetorical question when asked if you should floss before or after you brush your teeth.

While most people have their routine when it comes to caring for their teeth each day, there is actually an answer to the flossing before or after brushing question.

A study published in the journal Periodontology in March 2017 took on the question and found that flossing before brushing was the best way to do it.

Twenty-five dental students participated in the study. All the participants underwent prophylactic cleanings and then were told to cease oral care (brushing and flossing) for 48 hours.

After that, the study authors conducted a two-week interval analysis. In week one, participants brushed and then flossed. During the second week, they flossed and then brushed.

During each week, participants were evaluated for levels of plaque and fluoride before brushing and flossing.

The study found that flossing before brushing was the best option because it removed more plaque and bacteria from the teeth. The researchers also found that flossing before brushing meant a more significant chance that fluoride remains on the teeth.

This is beneficial because fluoride helps to remineralize the teeth and protect them against bacteria that cause tooth decay. It also means a decreased risk of developing gum disease.

To summarize the situation, flossing loosens up plaque between the teeth, and brushing removes it.

Dr. Ettiene van Zyl of Rogers, Arkansas, said flossing does 40 percent of the work of your toothbrush, reaching areas that brushing cannot.

Flossing also helps to prevent gum disease because it removes sticky plaque buildup from between the teeth.

“Removing the plaque from around the teeth reduces the chance bacteria will settle in and cause tooth decay and gum disease,” said van Zyl.

To maintain a healthy smile, individuals should brush at least twice per day and floss at least once per day.

So, when should you use mouthwash?

“At the very end of your oral hygiene routine. Using mouthwash or rinsing with water can help remove any bits of food debris that flossing or brushing failed to remove,” van Zyl said.

Source: Journal of Periodontology. The effect of tooth brushing and flossing sequence on interdental plaque reduction and fluoride retention: A randomized controlled clinical trial. March 2017.