How to Clean and Store Your Custom Whitening Trays (The Do’s & Don’ts)

If you have invested in professional teeth whitening in London with custom-fit trays, you will want them to stay comfortable, hygienic, and usable for as long as your dentist recommends. Custom whitening trays are designed to be reused — not only for your initial whitening course but often for future top-ups as well. How long they last, however, depends a great deal on how you clean, handle, and store them between sessions.

Many patients are unsure whether they can use toothpaste, hot water, or everyday cleaning products on their trays. The good news is that tray care is straightforward once you know the basics. This article offers general guidance on how to look after teeth whitening trays. Patients should always follow the specific instructions given by their own dentist, as materials and recommendations can vary.

Why Looking After Your Whitening Trays Matters

Well-cared-for trays fit better, feel more comfortable against the teeth and gums, and help whitening gel sit evenly across the enamel. When trays are clean and undamaged, the gel stays where it should — in close contact with the tooth surfaces — rather than pooling unevenly or leaking onto the gums.

On the other hand, trays that are damaged, warped, or carrying a build-up of dried gel and bacteria can become less comfortable, may produce less even results, and may need replacing sooner than expected. Since custom trays are made specifically for your teeth and form part of the overall teeth whitening cost in London, looking after them is a simple way to protect that investment.

The Basics — How to Rinse Your Trays After Whitening

Immediately after each whitening session, a quick rinse makes a real difference. The routine is simple:

• Remove the trays carefully and rinse them gently under cool or lukewarm running water
• Use your fingers or a very soft brush to remove any visible gel residue from the inside and outside of each tray
• Be careful not to pull, stretch, or twist the plastic while handling them

This helps prevent dried gel and plaque from building up, which over time can lead to odour, discolouration of the trays, or bacterial growth. Never leave trays sitting unwashed with gel still inside — even for a short period. The longer the residue sits, the harder it becomes to remove cleanly.

Can I Use Toothpaste on My Whitening Trays?

This is one of the most common questions patients ask, and the answer may be surprising: in most cases, regular toothpaste is not recommended for cleaning whitening trays.

The reason is that many toothpastes contain mild abrasive particles designed to scrub stains from tooth enamel. While this is fine for teeth, those same abrasives can scratch the softer plastic of whitening trays. Over time, scratches make the trays look cloudy and give bacteria more textured surfaces to cling to. Repeated scrubbing can also gradually alter the shape and fit of the tray.

Instead, use a soft toothbrush — ideally one kept just for your trays — with cool water. If your dentist recommends a cleanser, use a non-abrasive product designed for retainers or clear aligners. Always check with your dentist before using any cleaning product beyond water and a soft brush.

Why You Should Never Use Hot Water on Whitening Trays

Custom whitening trays are made from thermoplastic materials that hold their shape at room temperature and body temperature but can soften and warp when exposed to heat. Even moderately hot water from the tap can begin to distort the plastic.

Slight warping may not always be visible to the eye, but the fit of a custom tray is precise — it is made from an impression or scan of your individual teeth. Even a small change in shape can affect how securely the tray sits, how evenly the whitening gel is distributed, and how comfortable the tray feels against your gums.

The rule is straightforward: trays should only ever be rinsed in cool or lukewarm water. Never use hot water, boiling water, or place trays in a dishwasher. If trays do lose their shape, they may need to be remade by your dentist.

Do’s: Safe Ways to Clean Your Whitening Trays

Here is a practical checklist of good habits:

• Do rinse trays promptly in cool or lukewarm water after each use
• Do use a soft toothbrush (kept just for your trays) to gently brush away any remaining gel or plaque
• Do allow trays to air-dry completely on a clean surface before placing them back in their storage case
• Do follow any additional cleaning advice given by your dentist, including the occasional use of retainer-specific cleaning tablets if recommended
• Do inspect trays regularly for cracks, rough edges, or changes in fit

Gentle, regular cleaning after every session is far more effective — and safer for the trays — than infrequent, harsh scrubbing.

Don’ts: What to Avoid When Cleaning and Storing Trays

Equally important is knowing what not to do:

• Don’t use hot water, boiling water, or dishwashers — they can warp the plastic and ruin the fit
• Don’t use abrasive toothpaste, household cleaners, bleach, or mouthwashes containing strong alcohol, unless your dentist has specifically advised otherwise
• Don’t bend, twist, or bite down hard on the trays when removing them or “testing” their flexibility
• Don’t leave trays loose on a table, wrapped in tissue, or in a pocket — they can dry out, warp, or be thrown away by accident
• Don’t eat or drink anything other than water while wearing your trays

These points may seem obvious, but trays are lost or damaged far more often through small everyday oversights than through any dramatic accident.

How to Store Your Whitening Trays Safely Between Uses

When your trays are not in use, they should be kept in a clean, ventilated storage case — usually the one provided by your dentist. Proper storage protects them from physical damage, contamination, and accidental disposal.

Good storage habits include:

• Rinse and gently dry trays before placing them in the case
• Keep the case away from direct heat sources — radiators, sunny windowsills, car dashboards, and hot bathrooms can all reach temperatures high enough to warp the plastic
• Store the case in a consistent, easy-to-remember location so the trays are not easily misplaced
• Keep trays well out of reach of pets — dogs in particular are often attracted to the scent and may chew them if left within reach

Storing trays in a sealed container while they are still wet is not ideal, as a warm, damp environment can encourage bacterial growth. Allowing them to air-dry briefly before closing the case is a small step that helps keep things hygienic.

How Long Can Custom Whitening Trays Last with Good Care?

With careful cleaning and storage, custom whitening trays can often last for a significant period — potentially well beyond the initial whitening course. Many patients use the same trays for occasional dentist-advised top-ups over the months that follow, without needing a new set.

There is no fixed “expiry date” for custom trays. How long they remain suitable depends on how frequently they are used, how well they are looked after, and whether the fit remains accurate. Teeth can shift slightly over time, particularly if the patient does not wear a retainer after orthodontic treatment, and this can gradually affect how well the trays sit.

Patients should bring their trays to regular dental check-ups if they plan to continue using them for top-ups. The dentist can check the fit, assess the condition of the plastic, and advise whether the trays remain suitable or whether new ones should be made. If sensitivity or gum discomfort develops, reading about how we approach whitening for sensitive teeth may also be helpful.

When to Contact Your Dentist About Your Trays

There are several situations where it is worth getting in touch with your dental practice rather than continuing to use trays that may no longer be working properly:

• If the trays crack, tear, or develop rough edges that irritate the gums
• If they feel loose, no longer fit securely, or seem to have changed shape
• If they have been accidentally exposed to hot water or left somewhere very warm and appear misshapen
• If there is a persistent odour or build-up that does not improve with careful cleaning
• If you notice increased sensitivity or gum irritation when using the trays

It is always better to ask for advice and, if needed, have trays adjusted or remade rather than continuing to use poorly fitting trays that could affect comfort or results. Contact our clinic to discuss teeth whitening options if you have any concerns about the condition of your trays.

Next Steps if You Want to Make the Most of Your Whitening Trays

If you already have custom whitening trays, take a moment to review your cleaning and storage habits. Small adjustments — rinsing promptly after each session, using cool water only, drying before storing, and keeping trays in their case — can make a meaningful difference to how long your trays last and how comfortable they remain.

If you are unsure about any aspect of tray care, or if your trays are showing signs of wear, your dentist is the right person to ask. They can check the fit, recommend suitable cleaning products, and advise on whether your trays are still appropriate for future top-ups.

Good tray care supports comfort, hygiene, and more predictable whitening results. It is one of the simplest things you can do to help your professional home teeth whitening go as smoothly as possible.

Disclaimer: This article provides general information only and does not constitute personalised medical or dental advice. Cleaning and storage recommendations may vary depending on the specific tray material used by your dentist. Always follow the instructions provided by your treating dental professional.