A mouthguard that hasn't been moulded properly does half the job. It comes loose when you breathe hard, you have to bite it back into place between every round, and most people end up leaving it in their bag. A correctly moulded guard, on the other hand, stays in place on its own, even with your mouth open.
Here is the method step by step, what happens if you get it wrong, and how you can start again.
What you need
- A pan of water
- A bowl of cold water, ideally with a couple of ice cubes
- A large spoon or tongs to lift the guard out with
- A mirror
- Five minutes without being interrupted
How to mould the guard
- Bring the water to the boil and take it off the hob
The water should be freshly boiled, but not at a rolling boil when the guard goes in. Too high a temperature makes the plastic too soft and can make it curl up.
- Put the guard in the water for 20 to 30 seconds
Always follow the time on the packaging if it differs. Don't leave it in longer than instructed. Make sure it is fully covered by water.
- Dip it briefly in lukewarm water
One to two seconds. This takes off the worst of the heat so you don't burn yourself, without the plastic having time to set.
- Place it on your upper teeth
Place it straight on your teeth in front of the mirror, so your front teeth sit in the middle of the guard. A crooked start gives a crooked guard.
- Bite gently and suck hard
Bite down lightly, suck all the air out, and at the same time press your tongue against the roof of your mouth. Use your fingers to press the plastic against the gums at the front and sides. Hold for 30 seconds.
- Cool it in cold water
Take it out and put it in the cold water for half a minute so the shape sets.
How to test that it fits
Put the guard in, open your mouth and shake your head gently. A correctly moulded guard stays on your upper teeth without you doing anything. If it falls down, it isn't finished.
Also check that you can breathe and talk more or less normally, and that it doesn't reach so far back that it triggers your gag reflex. If it is too long, you can trim a few millimetres off the back with scissors, a little at a time.
Common mistakes
- Too long in the water. The plastic goes mushy and loses its structure. Stick to the time on the packaging.
- Using water at a rolling boil. Take the pan off the hob first.
- Biting too hard. Then the guard becomes thin over the chewing surfaces.
- Forgetting to suck. The suction is what pulls the plastic in against the teeth. Without it, the shape will be approximate.
- Cooling too early. Wait until the 30 seconds are up before you take it out.
- Placing it crooked. Use a mirror. It takes two seconds and solves the problem.
If the result is poor, most models can be heated and moulded again. The plastic then straightens out and you can try once more. Check the packaging for how many times the manufacturer recommends.
The exception: the ORTHO model
If you have braces, none of this applies. The ORTHO model must not be heated or moulded. It is built with a padded channel that sits over brackets and wires, and boiling it ruins exactly that channel. Rinse it in cold water and use it as it is.
More on this in the article on mouthguards for braces.
Care and lifespan
- Rinse in cold water before and after every session. Never hot water – it softens the plastic and ruins the shape.
- Let it air-dry before you put it in the case.
- Use a disinfectant spray regularly.
- Keep it in a case with air holes, not loose in your bag.
- Replace it when it has cracks, has gone hard or no longer stays in place on its own.
Our recommendations
Easiest to mould
The basic model. Forgiving to mould and a good first guard.
Better fit
Thicker over the front teeth and a little more work to mould, but fits better once it is done.
For those who spar a lot
A multi-layer construction with more cushioning. For those who have contact in every single session.
With braces
Not to be moulded. Built as a channel over brackets and wires.
After moulding
Spray after the session and let it dry. Together with a case with air holes, the guard stays fresh.
Frequently asked questions
Can I mould the guard again if I get it wrong?
Yes, most models can take several attempts. The plastic straightens out again when heated. Check the recommendation on the packaging.
How long should it stay in the water?
Usually 20 to 30 seconds. Always follow the packaging if it says otherwise.
Why does the guard fall down when I open my mouth?
Then it didn't get enough suction during moulding. Heat it up and try again, and remember to suck hard.
Should the guard go on my upper or lower teeth?
The upper teeth for the vast majority. Double models exist, but are mostly used in certain sports with special requirements.
Can children mould it themselves?
No. Boiling water should be handled by an adult. Let the child do the biting itself while an adult stands beside them.
How often should I replace my mouthguard?
When it has gone hard, has cracks or no longer stays in place on its own. For growing children that means more often than for adults.
