It is one of the questions we are asked most often, and the answer is simpler than people expect: brushing before breakfast is usually the better habit.
Why before is better
Overnight, plaque builds up on your teeth. Brushing when you wake up clears it away and coats your teeth in fluoride before you eat. That fluoride layer helps the enamel stand up to whatever comes next.
Many breakfasts are acidic. Orange juice, fruit, coffee and some cereals all soften the enamel surface for a while after you have them. If you brush straight after, you can wear away enamel that is temporarily weaker than normal. Over the years, that adds up to sensitivity and teeth that look more yellow as the enamel thins.
If you prefer brushing after
That is fine, as long as you wait. Give it about an hour after eating so your saliva has time to settle the acid and firm the enamel back up. In the meantime, a glass of water or sugar-free gum helps.
The bit most people get wrong
After brushing, spit out the excess toothpaste but do not rinse with water. Rinsing washes away the fluoride that protects your teeth. The same goes for mouthwash: use it at a different time of day, not straight after brushing.
The basics
Brush twice a day for two minutes, last thing at night and one other time.
Use a fluoride toothpaste. Adults should look for 1,350 to 1,500 ppm fluoride on the label.
Clean between your teeth once a day with floss or interdental brushes.
Use a soft or medium brush and gentle pressure. Scrubbing harder does not clean better.
If you are not sure whether your technique is right, ask at your next hygiene appointment. It takes a few minutes to check and is one of the most useful things we do.