When and How Often Should You Brush Your Teeth?
Most of you are likely to exclaim, ‘What kind of a question is that? Of course it’s twice a day!’ One the one hand, you are right: American healthcare organizations recommend this pattern. But questions remain: should it be done after or before breakfast? And how many times a day are enough? Is the Korean 3-3-3 approach more effective? Read on to find it out.

How often…
According to a recommendation issued by the American Dental Association, which is supported by Mayo Clinic, brushing teeth twice a day for a couple of minutes is sufficient for dental health. Keep in mind that this recommendation covers only brushing proper, so more time is spent on flossing and using mouthwashes.

…and when
As to when teeth should be brushed, i.e. before or after breakfast, it depends on what food you have for breakfast. The thing is, acidic foods, such as juices, grapefruit, tomatoes, etc., have a negative impact on your enamel, softening it and making it easier for bristles to damage it. This is why it is not recommended to brush teeth right after eating acidic foods. Still, as soon as your meal is not acidic, you can brush them whenever you like with no significant difference in effectiveness. Most dentists recommend that you do it before breakfast – to be on the safe side, perhaps. Others highlight the importance of the kind of food just consumed for choosing the best time for brushing. If there is nothing that prevents you from brushing teeth before eating, do it this way. However, if you prefer to postpone it till you enjoy a glass of juice with a fresh bun, wait for another hour after the meal and then proceed with brushing – by doing so, you will give your mouth enough time to remove most of the acids so that your enamel could not be damaged by the pressure of bristles. This approach is promoted by the American Dental Association, which says one of the two brushing sessions should be before going to bed, and the other one when you find it convenient, provided you follow the advice mentioned above and avoid brushing teeth when they are exposed to acids.References:
When and how often should you brush your teeth? – mayoclinic.org
How to keep your teeth clean – nhs.uk
Association between oral health behavior and periodontal disease among Korean adults: The Korea national health and nutrition examination survey – insights.ovid.com