Brushing your teeth: before or after breakfast?

Most of us learned how often to brush — twice a day, morning and evening. Very few of us were ever told when. How often should I brush my teeth? covers the frequency; this page covers the timing.

Some people brush the moment they get out of bed, before eating. Others brush just before leaving home, after breakfast. It turns out the difference matters.

The short answer: brush before breakfast. The reasoning is below, along with what to do if that does not suit your morning. The full routine is at what is the ideal daily routine for oral hygiene?

Why timing matters

If your breakfast includes anything acidic — fruit juice, coffee, citrus — the acid temporarily softens the enamel surface of your teeth. How does acidic food affect your teeth? and I've heard a lot about acid wear. What is this and how can I avoid it?

Brushing immediately afterwards means you are brushing softened enamel. Rather than cleaning it, you can abrade it, leading to wear and sensitivity over time. What is dental erosion and how is it addressed? and if enamel is the hardest substance in the body, why do teeth break?

This is the counterintuitive part: the brushing itself is not the problem, and neither is the juice on its own. It is the combination, in that order.

The underlying chemistry is not in dispute. The Australian Dental Association's policy on diet and nutrition states that "exposure to acid from the consumption of acidic or sugar-sweetened foods and beverages can lead to softening and loss of tooth structure", and that "the combination of sugar and food acid can be particularly destructive" — which describes a glass of juice precisely.

A typical breakfast is more acidic than most people realise. Orange juice sits around pH 3.5. Coffee is around pH 5. Citrus fruit, tomatoes, many fruit yoghurts and most fruit and herbal teas are all below the pH 5.5 threshold at which enamel starts to dissolve. The same logic applies to anything acidic later in the day — are sugar free soft drinks better for my teeth than regular soft drinks? explains why removing the sugar does not remove the acid, and what are sports drinks really doing to your teeth? and what impact does wine have on my teeth? cover two more.

How long you need to wait

It takes at least half an hour for saliva to counterbalance the acid attack and restore a neutral pH in the mouth. Healthdirect Australia gives the same interval as a flat instruction: "Ideally, wait 30 minutes after eating and drinking to brush your teeth." An hour is a safer margin, particularly for anyone who already has enamel wear or sensitivity. What to do if you suffer from sensitive teeth

So if you brush after breakfast, wait at least 30 minutes. For a lot of people that is simply not practical on a weekday morning — which is the real argument for brushing first.

Where the advice differs, and why we say so

It would be tidier to tell you everyone agrees. They do not. Healthdirect Australia names the best times to brush as "in the morning after breakfast and before going to bed at night" — after, not before — and then attaches the 30-minute rule to it.

The disagreement is narrower than it looks, because both positions exist to stop you brushing softened enamel. Healthdirect gets there by making you wait; brushing first gets there by putting the brush in before the acid. If your mornings have thirty spare minutes in them, healthdirect's version works. If they do not — and most do not — brushing first avoids the problem without relying on a wait that never happens. What neither source endorses is the common third option: juice, then straight to the bathroom.

Why brushing before breakfast is actively good, not just a compromise

It is often presented as the lesser evil. It is better than that:

• It removes the plaque that accumulated overnight before you feed it breakfast. Plaque is a biofilm, and only mechanical disruption removes it — no rinse, oil or paste does that job on its own. Plaque bacteria turn breakfast carbohydrate into acid within minutes, and there is less of that if the plaque has just been disturbed. The ADA puts the stakes plainly: tooth decay and gum disease are "two of the most common diseases experienced by Australians", and "plaque is the primary cause of both". How does tooth decay develop? and how does sugar affect your dental health?
• It puts fluoride on the teeth before the acid arrives, which is exactly the right order. The NHMRC describes fluoride as working two ways — "reducing demineralisation (i.e. where the enamel begins to dissolve)" and "enhancing remineralisation (i.e. recovery of weakened enamel)" — and adds that it "slows the activity of bacteria that cause decay and combines with enamel on the tooth surface to make it stronger". Every one of those is worth having in place before breakfast rather than after it. The benefits of fluoride and selecting a toothpaste: fluoride or non-fluoride
• It removes the overnight bacterial load, which is what morning breath is. Healthdirect treats that as ordinary physiology rather than a problem: "It's normal to have bad breath when you wake up in the morning." What causes bad breath and how can I fix it? and should I use a tongue scraper?

And the step almost nobody is told: spit, don't rinse. After brushing, spit out the excess and do not rinse with water. Rinsing washes away the concentrated fluoride that would otherwise keep working on the tooth surface for another hour or more. This single change improves every brush you will ever do, and it costs nothing.

It also means the fluoride is still working while you eat breakfast. The NHMRC makes the related point about Melbourne's tap water: fluoridated water "keeps low levels of fluoride in saliva and in dental plaque all day", while "the much higher concentration of fluoride in toothpaste offers additional benefit" — the two work together rather than substituting for one another.

What to do instead

There are three workable answers:

1. Brush before breakfast. Simplest option, and it removes the overnight plaque before you eat.
2. Rinse with water and chew sugar-free gum while you wait out the 30 minutes. Both help freshen the mouth and support the return to neutral pH, and the ADA lists "sugar-free confectioneries without added acids, including chewing gums" as dentally safe alternatives — does chewing sugar-free gum really help prevent cavities?
3. Keep a toothbrush and toothpaste at work, or take them with you, and brush once the half hour has passed — how to care for your toothbrush covers storing a travelling brush, which people get wrong.

What you should not do is rinse with an acidic mouthwash in place of brushing, or brush harder to compensate for brushing later. Harder is not cleaner, and the recession it causes does not grow back — over brushing: what can it do to my teeth?, how much pressure should I apply when brushing my teeth? and the truth and myths about mouthwashes.

Other things that help in the meantime: finish with something neutral or alkaline — water, plain milk, or cheese. Drink juice with the meal rather than sipping it, and use a glass rather than nursing a bottle through the morning. Contact time is what does the damage. The ADA's own list of habits that raise acid risk includes two people rarely think of: sipping drinks other than water during interrupted sleep, and chewing or sucking acidic vitamin tablets. How does your diet affect your teeth? and six foods to avoid for healthy teeth

The brush that matters more than either

Worth putting plainly: if you only get one brush right, make it the last one of the day.

Salivary flow falls markedly during sleep, so for around eight hours the mouth's own defence — the thing that buffers acid and remineralises enamel — is at its lowest. Anything left on the teeth at bedtime sits there unopposed. That is worse again for anyone whose mouth is dry to begin with: my mouth is always dry — why is this and does it affect my teeth?

So: brush last thing, spit don't rinse, and nothing but water afterwards. The morning question is worth getting right. The night one matters more. And the brush does not reach between the teeth at any hour — is flossing really that important?

In summary

• Brush twice daily and clean between your teeth at least once a day. That remains the foundation — two minutes, a soft brush, and no more than twice. It is also, word for word, the Australian Dental Association's list of the main oral hygiene strategies.
• If you have just consumed something acidic, wait at least 30 minutes before brushing — an hour is better.
• Brushing before breakfast avoids the problem entirely, and has advantages of its own.
• Spit, don't rinse.

For most households, brushing before breakfast is the change that requires the least effort and removes the risk entirely.

Common questions

What if my breakfast is not acidic — just toast and tea? Then the timing matters much less. The rule is about acid, not about food in general. Unsweetened tea without lemon is close to neutral — are there antibacterial properties in tea?

Should I rinse with mouthwash after an acidic breakfast? Not with an acidic one, and not as a substitute for brushing. A fluoride rinse at a different time of day is reasonable; plain water immediately after is the useful thing. The ADA classifies mouthrinse as a "proven aid to oral hygiene" but deliberately leaves it out of the main strategies — an addition, never a replacement. Should I be using mouthwash as well as brushing and flossing my teeth?

Is it bad to brush twice in the morning — before and after? Not harmful, but unnecessary, and the after-breakfast one carries the abrasion risk. Once, before, is enough. More brushing is not better.

Does an electric toothbrush change the answer? No. If anything the timing matters slightly more, because the brush does the work whether or not you moderate the pressure.

My teeth are already sensitive in the mornings. Have it looked at. Sensitivity has several causes — erosion, recession, grinding, a cracked tooth — and they are managed differently. Night time tooth grinding and clenching, why does a cracked tooth hurt so much? and tooth pain and toothaches

What if my gums bleed when I brush in the morning? That is inflammation, not a sign of brushing too hard, and it should be reported rather than avoided — bleeding gums and what is gum disease?. Floss reaches about 3mm below the gum margin; a pocket of 5mm or more is periodontitis and needs professional treatment, not a better morning routine — when do you need deeper cleaning?

Related reading

• 3 oral hygiene tips you need to know
• Choosing the right toothpaste for you
• Dental cleans and hygienists
• Your Smile Solutions dental hygienist visit: what to expect
• Bad breath
• Kids teeth cleaning tips
• How to encourage your child to brush their teeth
• Health problems linked to poor oral hygiene

Practical details

Smile Solutions, Level 1, 220 Collins Street, Manchester Unity Building, Melbourne VIC 3000 — getting here. Phone 13 13 96, contact us, or theteam@smilesolutions.com.au. Monday–Friday 8.00am–6.00pm, Saturday 8.30am–1.30pm, Sunday by appointment. Published fees are in the price guide.

If you already have enamel wear or sensitivity, a hygienist or dentist can assess how much is from acid erosion and how much from brushing technique — the treatment differs, and getting that distinction right is the whole of the management. General dentistry, what does a dental hygienist do? and the clinical team.

Every practitioner's registration can be verified free on the AHPRA public register at ahpra.gov.au.

Published 7 September 2016. General information only — it is not a diagnosis or a treatment plan, and it does not replace advice from your treating practitioner.

Smile Solutions trades under ABN 28 193 514 103.