Teeth whitening
What does teeth whitening involve?
Take-home whitening from $550 lightens teeth by several shades over ten to fourteen nights using trays moulded to your mouth; in-chair whitening from $795 does similar work in one 90-minute visit. Both need a current check-up first, because peroxide gel over decay or an untreated crack causes real sensitivity.
From $550 — take-home kit with custom trays
At a glance
- Take-home from
- $550, including custom trays and gel
- In-chair from
- $795 for one 90-minute visit
- Appointment length
- 20 minutes to scan for trays, 90 minutes in chair
- Prerequisite
- An examination within the last twelve months
- Typical result
- Several shades over ten to fourteen nights, held with top-ups
How whitening actually works
The active ingredient is peroxide. It passes through enamel into the dentine beneath and breaks apart the large pigment molecules that years of tea, coffee, red wine, smoking and curry have deposited there. Nothing is scraped off and no enamel is removed — the tooth is the same thickness afterwards, with lighter pigment inside it.
That also explains the limits. Whitening changes the colour of tooth structure and nothing else, so it lifts general yellowing well, does very little for grey discolouration from old trauma or tetracycline, and can make white patches look briefly more obvious before the surrounding tooth catches up.
Take-home versus in-chair
Take-home is the workhorse. We scan your teeth, the laboratory makes thin trays that fit your arch exactly, and you wear them with a measured line of gel for an hour or two a day — or overnight with a gentler gel — for about two weeks. The result builds gradually, you control the pace, and you keep the trays for a top-up in a year or two.
In-chair suits a deadline. Your gums are isolated with a barrier, a stronger gel goes on in three or four passes over roughly ninety minutes, and you leave visibly lighter the same day. It is more prone to short-lived zingy sensitivity, and most people still go home with trays to hold the result.
Sensitivity, and how to keep it manageable
Some sensitivity during a whitening course is normal and it settles once you stop — peroxide temporarily opens the microscopic tubules in dentine. It is manageable: use a sensitive toothpaste for a fortnight beforehand, shorten each wear to an hour, skip a night when your teeth feel sharp, and do not double the gel to go faster, which only trades comfort for no extra shade.
What we check before you start
A current examination, because gel finding a cavity or a crack is the single most common cause of a miserable whitening experience. We also record your starting shade and note every crown, veneer and white filling in your front teeth. Those do not lighten. If a front crown currently matches a stained tooth, whitening the teeth around it will leave it looking dark, and the fix is replacing the crown afterwards — better to know that before, not after.
Making it last
Expect a couple of years from a full course if you are not a heavy coffee or red wine drinker, less if you are. A single night of gel every few months holds the shade far more cheaply than starting again. Rinsing with water after coffee helps more than brushing straight afterwards, which rubs acid into softened enamel.
Teeth whitening — common questions
- How long does teeth whitening last?
Usually a year or two from a full course, and less if coffee, tea, red wine or smoking are daily habits. The honest way to think about it is maintenance rather than a one-off: a single night of gel in your existing trays every few months holds the shade, and costs a fraction of repeating the whole course. Keep the trays — they stay usable for years.
- Will whitening work on crowns, veneers or white fillings?
No. Peroxide only changes natural tooth structure, so porcelain and composite stay exactly the shade they were made. That matters most in the front teeth: whitening the teeth around a matched crown will leave the crown looking dark by comparison. We note every restoration in your smile line before you start, and where it is going to be a problem we say so and price the replacement, so you can decide in advance.
- Is whitening safe if my teeth are already sensitive?
Usually yes, with adjustments. Sensitivity during whitening is temporary and reversible, but it is worse in people who start out sensitive. Two weeks of desensitising toothpaste first, a lower-concentration gel, shorter wear times and a night off whenever teeth feel sharp make a real difference. If sensitivity is coming from something specific — a crack, gum recession, decay — that gets treated first.
- Are supermarket whitening kits worth trying?
They are cheap and largely harmless, and they will not do much. Over-the-counter kits are capped at low peroxide concentrations, and their one-size strips or boil-and-bite trays leak gel onto the gums instead of holding it against the tooth. The bigger risk is skipping an examination: whitening over undiagnosed decay hurts and delays the treatment the tooth needed anyway.