You might think brushing your teeth requires no rules, as we have been taught to simply brush up and down and round and round.

But according to expert advice, there is one simple step to brushing your teeth that you should never do.

The founder of Marylebone Smile Clinic, Dr Sahil Patel says one of the biggest mistakes you can make is to wet your toothbrush before adding toothpaste to it.

Why you shouldn't do this one common step when brushing your teeth

The cosmetic dentist explained to The Sun: "If you wet the toothbrush before you put the toothpaste on, you're diluting it.

"Toothpaste already has the right amount of moisture. If it's wet, it makes it foam up faster and makes you spit it out sooner."

People should also make sure they do not rinse with water straight after toothbrushing.

This is because it will wash away the concentrated fluoride in the remaining toothpaste and rinsing dilutes it, reducing its preventative effects, reports the NHS.

Dr Patel recommended another tip for brushing your teeth the correct way and said you should start your clean from the back of your teeth.

He added: "I'd recommend starting at the back first, which is often the hardest part to clean.

"If you start at the front and do the back last, you're more likely to stop and put it down, missing the back or not cleaning the back properly."

The expert also offered advice on the use of dental floss and urges people to use interdental brushes instead.

Bradford Telegraph and Argus: If there's one time of the day you shouldn't skip brushing your teeth, it's in the eveningIf there's one time of the day you shouldn't skip brushing your teeth, it's in the evening (Image: Canva)

Dr Patel commented: "The bristles that clean between the teeth can get to corners and tricky areas that the toothbrush can't get to clean our plaque, this makes them more effective than floss and they come in many shapes and sizes to ensure a good fit.”

How often should you brush your teeth?

The dentist said he would rather someone brushed their teeth properly once a day, rather than "twice a day slap dash".

He said: "Problems start when we miss certain areas regularly and then this turns into a problem, so it's better to brush once and well, than twice and poorly."

The one particular time you shouldn't miss out on brushing is in the evening.

Dr Patel said: "Don't miss the evening brush. The saliva in your mouth reduces while you sleep, so the food that you've had during the day will stay in your teeth and fester overnight, causing bigger problems."