Home teeth whitening with custom trays means wearing thin trays made from moulds of your own teeth, filled with a small amount of gel prescribed by your dentist. Worn daily, usually for two to six weeks, they lighten teeth gradually. Because the trays fit closely and your teeth are checked first, it is a gentle, controlled way to whiten.
What custom-tray whitening is and who it suits
Home whitening uses the same chemistry as whitening in the dental chair, at a gentler pace. The gel usually contains carbamide peroxide, a compound that slowly releases hydrogen peroxide. This breaks down the stain molecules inside the tooth without removing enamel.
It suits adults with healthy teeth and gums whose teeth have yellowed with age, coffee, tea or smoking, especially if they prefer a gradual change or have sensitive teeth. To compare methods, see our guide to in-clinic and at-home teeth whitening; to understand the cause of your colour, read why teeth turn yellow.
Crowns, veneers and tooth-coloured fillings do not change colour. Whitening is usually postponed during pregnancy and breastfeeding, and it is not meant for children or young teenagers.
Getting your trays: examination, impressions and fitting
- Examination: cavities, leaking fillings, cracks and gum disease are treated first, because gel reaching them can hurt. A scaling and polish is often done beforehand.
- Starting shade: your current shade is recorded with a shade guide, so progress can be judged objectively.
- Impressions: moulds of your upper and lower teeth are taken with a soft material that sets within a few minutes. It is not painful.
- Making the trays: thin, flexible plastic trays are shaped on models of your teeth and trimmed to follow your gum line, so the gel stays on the teeth.
- Fitting: the dentist checks the fit and shows you how to load the gel and how to place and remove the trays.
Your daily whitening routine, step by step
How long you wear the trays depends on the gel prescribed: some gels are worn for about half an hour to a few hours during the day, others overnight. Always follow your own instructions.
- Brush and clean between your teeth, then rinse.
- Place a small drop of gel inside the tray, on the front surface of each tooth to be whitened. More gel does not work faster; it only spreads onto the gums.
- Seat the trays and press them gently into place.
- Wipe any gel off your gums with a clean finger or a tissue.
- After the prescribed time, remove the trays, rinse your mouth and brush away any remaining gel.
- Rinse the trays in cool water, let them dry and store them in their case.
What to avoid during the course
- wearing the trays longer or more often than instructed, or adding extra gel;
- gel from another source, such as online sellers;
- eating, drinking or smoking with the trays in, and smoking or narghile during the treatment weeks;
- coffee, tea, cola and red sauces in the hours after a session;
- heat: hot water, a hot car or direct sun can warp the trays or spoil the gel.
How many days or weeks it takes
A first change often shows within a few days, and a typical course lasts around two to six weeks, as the NHS guidance on teeth whitening also notes for trays made by a dentist. Yellowish teeth usually respond faster than greyish ones, and the canines, which are often naturally darker, may take a little longer.
You can stop as soon as you like the shade. There is no need to finish the gel, and continuing brings little benefit but more sensitivity. Teeth look slightly whiter just after removing the trays because they are briefly dehydrated; the colour settles within a day or two.
Managing sensitivity and sore gums
Temporary sensitivity, meaning short, sharp twinges often with cold drinks, is the most common side effect and usually fades once treatment stops. Gel touching the gums can leave small white patches that disappear within hours. To ease sensitivity:
- take a day or two off, or whiten every other day;
- shorten the wearing time, with your dentist’s agreement;
- use a toothpaste for sensitive teeth, ideally from a week or two before you start;
- ask whether a desensitising gel can be used in the trays on rest days.
Contact your dentist if pain is strong, lasts several days or centres on one tooth, which may point to a crack or a cavity. For a calm look at the evidence, read whether teeth whitening damages enamel.
Custom trays versus shop-bought kits and strips
| Feature | Trays made by your dentist | Shop-bought strips and kits |
|---|---|---|
| Check-up first | Yes, problems are treated before whitening | No |
| Fit | Made for your teeth, so gel stays on them | One size; strips can slip and gel can reach the gums |
| Gel | Chosen by the dentist for your teeth | Often weak, with modest results; some online products are not regulated |
| Follow-up and reuse | Shade and gums are checked; trays are kept for touch-ups | No follow-up; usually single use |
Touch-ups and what affects the cost
Whitening is not permanent, especially with coffee, tea and smoking. Keep your trays: a short top-up of one to a few days every several months, as your dentist advises, often maintains the shade. Bring them to check-ups, because new fillings, crowns or small tooth movements can change the fit. Some people begin with an in-clinic session such as laser teeth whitening and then use trays to complete and maintain the result.
The cost depends on whether trays are used alone or with an in-clinic session, the amount of gel, any treatment needed first such as scaling or fillings, whether visible fillings or crowns will need replacing to match, and later top-up gel. A clear estimate is only possible after an examination.
Home whitening at Ajam Dental Clinic in Tripoli
Ajam Dental Clinic offers home whitening with custom-made trays supplied by the clinic, as well as laser teeth whitening, as part of its cosmetic dental treatments. Aesthetic dentistry is the focus of Dr. Abdel Rahman Ajam, who holds an MSc in Aesthetic and Prosthetic Dentistry. Check-ups, scaling and polishing are also available to prepare your teeth.
We welcome patients at our clinic on Fouad Chehab Boulevard from across Tripoli, including El Mina, Abu Samra, Al-Tall, Zahriyeh and Bahsas, as well as from Qalamoun and the rest of North Lebanon. To book a consultation, send a WhatsApp message to one of our dentists through our contact page.
Frequently asked questions
Can I sleep with my whitening trays in?
Only if your dentist has prescribed a gel designed for overnight wear. Some home whitening gels are made to work slowly over several hours and are worn while you sleep; others are meant for a shorter time during the day and should not be left in overnight. The wearing time is part of your prescription, so do not change it on your own. If you prefer one routine over the other, for example because daytime wear does not fit your work, mention it at the fitting appointment. The dentist can usually choose a gel and schedule that suit your day.
What should I do if I miss a day or run out of gel?
Missing a day is not a problem. Simply continue the next day as usual; there is no need to double the wearing time or add extra gel to catch up. Whitening builds up gradually, so one missed session only delays the result slightly. If your gel runs out before you have reached the shade you want, contact the clinic rather than buying a product elsewhere. The dentist may want to check your progress and your gums before giving you more gel, especially if you have had any sensitivity during the first weeks.
Can I use whitening gel bought online in my custom trays?
It is better not to. Your trays are designed for the gel your dentist has chosen, with instructions on how much to use and for how long. Gels sold online may have an unknown strength, may not follow any safety rules, and some contain ingredients that can irritate the gums or harm enamel. Using an unknown product also makes it harder to understand what went wrong if sensitivity appears. If you need more gel for a touch-up, ask the clinic, so that the product and the schedule stay matched to your teeth.
Can I eat, drink or smoke while wearing the trays?
No. Food and drink can get trapped under the trays, dilute the gel and stain the teeth just as they are most receptive to colour. Smoking with the trays in, or during the treatment weeks in general, works directly against the result, and that includes the narghile. If you are thirsty during a daytime session, remove the trays first, drink some water and put them back with a little fresh gel only if your dentist has said so. After each session, wait a while before having coffee, tea or other dark drinks.
My teeth show white spots during treatment. Is that normal?
Yes, it is common. Whitening temporarily dehydrates the enamel, and some areas, especially existing faint white marks, can look brighter or chalky for a while. In most cases, the spots blend in within a day or two as the teeth rehydrate, and the overall colour becomes more even as the course continues. If the spots stay after you have finished, or you notice spots together with pain, show them to your dentist. They can check whether they are part of your natural enamel pattern and suggest options if they bother you.
Will my trays still fit in a year or two?
Often they will, as long as your teeth have not changed. Trays are made from thin plastic shaped on models of your teeth, so they can keep fitting well for a long time if you store them dry, in their case and away from heat. However, a new crown, a large filling, an extraction or small movements of the teeth can change the fit. A tray that no longer fits lets gel leak onto the gums. Bring your trays to a check-up before a touch-up, and the dentist can tell you whether new ones are needed.
Have a question about your teeth?
Send a WhatsApp message to Dr. Abdel Rahman Ajam or Dr. Soumaya Ajam, or call the clinic to book a consultation.
This article provides general information for patients. It does not replace an examination by a dentist, who can advise you on your own situation.
