If you cannot breathe comfortably through your nose, move an in-chair teeth whitening session and pause take-home trays for a few days, because whitening with a cold or blocked nose is uncomfortable and gives you nothing extra. A mild cold with a clear nose usually causes no problem at all. A cold rarely lasts long, either: healthdirect notes that symptoms usually get better on their own within 7 to 10 days, so a short delay costs very little.
Written by Dr James Tran, BDent (University of Sydney), MICOI, GradDip (Oral Implants), general dentist at Lumi Dental in Melrose Park.
The short version
- Whitening gel does not make a cold worse, and a cold does not stop the gel working. The problem is breathing and comfort.
- An in-chair session keeps your mouth held open with a retractor for a long stretch, so you need to breathe through your nose. Our guide to what happens at in-chair whitening walks through the appointment.
- Take-home trays worn while you mouth breathe tend to feel dry and unpleasant, and coughing or sneezing can push gel out over the gums.
- Fever, aches or flu symptoms mean staying home and calling to move the appointment.
- Aching upper back teeth during a sinus infection are usually not whitening sensitivity.
- A short break from trays usually costs very little. You pick up where you left off once you can breathe freely.
The single rule: no clear nose, no whitening that day
If you cannot breathe comfortably through your nose, move an in-chair whitening session and pause take-home trays for a few days rather than wearing them while mouth breathing. If your nose is clear and you feel well apart from a scratchy throat or the tail end of a cold, whitening can usually go ahead as planned.
A simple test helps: close your lips and breathe through your nose for a minute while sitting back in a chair. If you are reaching for air through your mouth within a few breaths, reschedule. In my experience, patients who try this the night before make a better call than those who decide in the car park.
Why an in-chair session depends on nose breathing
In-chair whitening uses a strong gel that only a dental practitioner can apply. To keep it off the lips and gums, a cheek retractor holds the lips back, a protective barrier is painted over the gums, and the gel goes on in rounds while you sit back with your mouth open. The NHS describes in-surgery whitening as usually one appointment of around 1 to 2 hours, and for most of that time your mouth stays open.
With a blocked nose, you end up breathing through a held-open mouth, which dries the lips and tongue, makes you swallow more often and can trigger coughing. A sneeze may disturb the gum barrier, so the team has to stop, check and reapply. Lying back makes congestion feel worse for many people, too. Our article on going to the dentist with a cold or flu covers general appointments; whitening is elective, so a short delay has no clinical cost.
Take-home trays and mouth breathing
Take-home whitening uses thin custom trays and a lower-strength gel, worn for around 2 to 6 weeks according to the NHS. With a blocked nose, three things get in the way.
A dry mouth under the tray
Breathing through the mouth dries the teeth, lips and gums. A small study from the University of Otago fitted ten healthy adults with a pH sensor and had them sleep with a nose clip to force mouth breathing. Their average mouth pH during sleep fell from 7.0 to 6.6. It was a small group, but it fits what people describe: a parched mouth by morning. A tray of gel on dried teeth can feel tacky, and some people notice stronger sensitivity twinges.
Coughing, sneezing and swallowing gel
A hard cough or sneeze can lift a tray and squeeze gel over the gum edge, and a sore throat means more swallowing. The NHS lists sore gums or throat among whitening side effects, and wearing trays through a cough makes both more likely. With a mild cold, use less gel, wipe away any excess and remove the tray if you start coughing.
Overnight wear is the hardest
Congestion is usually worst at night, when you mouth breathe without noticing. If you normally whiten overnight, switch to shorter daytime wear while you are blocked up, or pause.
Lozenges, syrups and hot drinks while whitening
- Lozenges: many are sugary and dissolve slowly. Never suck one with a tray in; sugar-free versions are kinder between sessions.
- Syrups: often sweet and sticky. Take them after a session rather than just before, then rinse with water.
- Hot lemon and honey: soothing, but acidic and sweet. Rinse with plain water before a tray goes in.
- Tea and coffee: both stain, so many dentists suggest avoiding them for a few hours after a session.
Some decongestants can also dry the mouth; our article on decongestants, cold medicines and your teeth covers the detail.
| Symptom | In-chair session | Take-home trays |
|---|---|---|
| Mild cold, nose clear, feeling well | Usually fine to go ahead; mention it when you arrive | Usually fine; daytime wear may be more comfortable |
| Blocked nose, mouth breathing | Reschedule until you can breathe through your nose | Pause for a few days; avoid overnight wear |
| Fever, aches or flu symptoms | Stay home and call to move the appointment | Pause until you feel well again |
| Sinus pressure or aching upper back teeth | Reschedule; have the ache checked if it lingers | Pause; a sore tooth is not a reason to push on |
| Sore throat, using lozenges | Often fine if your nose is clear; avoid lozenges just before | No lozenges with trays in; rinse with water before wearing |
Fever, flu and calling before you come
A cold and the flu are different illnesses. healthdirect describes the flu as causing fever and chills, sneezing, coughing and a sore throat, and advises that if you are sick with the flu you should stay home and avoid close contact with other people until you feel better. For colds, healthdirect also says you should stay home when you are sick to stop the spread, and suggests coughing and sneezing into your elbow or a tissue and washing your hands.
A whitening appointment means people working close to your face for an hour or more, with other patients in the waiting room. If you have a fever, a heavy cough or feel flattened, call before you come. For contact details and current hours, see the contact page.
Sinus ache is not whitening sensitivity
Colds can lead to sinusitis, and healthdirect lists it among the possible complications. The roots of the upper back teeth sit just below the floor of the maxillary sinus, so a congested sinus can make several upper back teeth ache together. That ache is usually dull and often heavier when you bend forward.
Whitening sensitivity feels different. It is a short, sharp twinge, often set off by cold, in the teeth the gel touched. If your upper back teeth ache with a blocked nose partway through a course, pause the trays and let the sinus settle. Our article on sinus toothache and referred pain explains how a dentist tells the two apart. I usually ask patients whether the pain is in one tooth or a whole row: one tooth that aches to biting or cold needs a check whatever is going on with your nose.
Restarting after a break, and a cold sore that turns up
Picking trays back up
A few days off take-home whitening usually does not undo the shade you have reached, though teeth may look slightly less bright for a day or two as they rehydrate. Restart once your nose is clear and count the days you have left rather than starting again. Our guide to missed days or stopping take-home whitening halfway covers longer gaps.
A cold sore with the cold
Colds and cold sores often arrive together, and a blister on the lip is a reason to wait. Our article on whitening with a cold sore or mouth ulcer explains when it is safe to go ahead.
Hay fever is not contagious and can last for weeks, but the same nose-breathing test applies.
How we approach this at Lumi Dental
Whitening at Lumi Dental starts with an examination by the dentist, who checks the teeth and gums are healthy before any gel is used. The whitening options are named Lumi Home, Lumi Refresh and Lumi Radiance, and the team can talk through which suits you at a consult. If you wake up blocked or feverish on the day of an in-chair session, call and the team will find another time. If you are unsure whether to pause a take-home course, the dentist or an oral health therapist can advise. More detail is on our teeth whitening page.
Questions patients ask
Can I get my teeth whitened if I have a cold?
Often, yes, if your nose is clear and you feel well. If you are blocked up or mouth breathing, move the in-chair session, because you need to breathe through your nose for most of it.
Should I wear whitening trays with a blocked nose?
It is usually better to pause for a few days. Mouth breathing dries the teeth under the tray, and coughing or sneezing can push gel onto the gums. Restart once you can breathe comfortably.
Will a few days off trays ruin the results?
Usually not. A short break tends to pause progress rather than reverse it, and you carry on with the days left in your course.
Can I use cough lozenges while whitening my teeth?
Not with a tray in. Many lozenges are sugary, so take them between sessions, choose sugar-free where you can and rinse with water before wearing a tray.
Why do upper back teeth hurt with a cold?
A congested sinus sits just above the roots of the upper back teeth and can make several of them ache together. If one tooth stays sore after the cold clears, have it checked. A complimentary cosmetic consult is also a good time to raise it before you restart whitening.
Thinking about whitening? Complimentary cosmetic consult in Melrose Park
If a cold has put your whitening on hold, the team at Lumi Dental can plan a restart around it. Book a complimentary cosmetic consult at Melrose Central in Melrose Park, or read more about teeth whitening at Lumi Dental. Patients visit from Ryde, Parramatta, Ermington and Rydalmere, with on-site parking.
Sources
- healthdirect: Colds
- healthdirect: Flu (influenza)
- NHS: Teeth whitening
- PubMed: Intraoral pH and temperature during sleep with and without mouth breathing
About the author
Dr James Tran is a general dentist at Lumi Dental in Melrose Park. He holds a BDent from the University of Sydney and a Graduate Diploma in Oral Implants, and is a Member of the International Congress of Oral Implantologists (MICOI).
This article is general information only and is not a substitute for an examination and individual advice from a registered dental practitioner. Suitability for any treatment varies from person to person.
