How Does Teeth Whitening Work? Inside the Tooth

An imperfect smile costs more than a mirror moment. In a hiring survey built on photos of made-up applicants, those shown with visible dental flaws had a 52% lower chance of being hired.[10] GENERAL: those photos showed decay and crooked teeth, not yellowing. Colour is a fast part to change, and it changes from inside the tooth.

A professional treatment crosses enamel and breaks the stain colour held in the dentine underneath; scrubbing the outside never reaches it. Three things decide how far it goes: how strong the gel is, how many minutes it stays on, and the colour your teeth already hold.

Predictive Whitening™ is how UpWhiten sets all three, with a NanoChroma™ reading before any gel and again at the end. You are buying a shade, not sessions.

How a bleaching gel changes the colour inside a tooth

A bleaching gel changes colour inside the tooth, where the stain sits. Enamel is the clear outer layer; the dentine beneath it carries most of the colour you see. The gel soaks through enamel and breaks the stain molecules apart, and nothing is drilled, scraped or worn away.

In a trial of sixty adults, an in-office treatment changed the colour visibly for over 80% of them, in every third of the tooth.[3]

Does hydrogen peroxide whiten teeth

Hydrogen peroxide is the chemistry that moves tooth colour, and strength decides how far it moves. In a trial of a hundred and forty adults, a strong professional gel whitened significantly more than a weak one, at every time point measured.[2]

The gum barrier and the desensitising protocol are part of every session at the studio. Our record is under 6% temporary sensitivity. If a round stings, tell us and we stop it.

What happens when strong peroxide goes home unsupervised

A laboratory test ran over-the-counter whitening pens for eight hours a day, ten days running.[6] The pen carrying the strongest gel softened enamel and pushed the most peroxide into the pulp chamber.[6]

How do dentists bleach teeth?

Dentists bleach teeth in two ways, a strong gel in the chair or a weaker gel worn at home in a tray. In one trial, just over three chair rounds of fifteen minutes reached six grades of whitening.[1]

The tray runs about eight hours a night for about fourteen nights by the dentists’ own guideline.[7] Either way, someone holds a plastic shade tab beside your teeth and decides by eye. That is the old way.

Can you whiten teeth in one day?

Yes, the colour moves on the first day. In one trial, in-office gel reached six grades of whitening after an average of under an hour of total gel time, across its rounds.[1]

At UpWhiten, your consultation can become your first session the same day. Every way to get whiter teeth is compared on its own page.

Three things set where a shade stops

Strength, contact minutes and starting colour set where a shade stops, so the real question is who controls them. At the studio all three are set in the chair against your reading.

The eye is the weak instrument. Across six pooled studies of shade matching in the mouth, instrument readings beat the eye.[8] NanoChroma™ reads your teeth at both ends of every session. A box of strips hands you all three levers and checks none, so it cannot tell you when you are done.

Whitening moves natural tooth colour only. A crown, veneer or bonded edge keeps the shade it was made in. A tooth greyed from an old injury belongs with a dentist.

Route by route: who holds each lever, and how deep each product reaches

The three levers, and who holds each one, route by route.

Route	Who sets the strength	Who counts the minutes	Who reads the colour
A session at UpWhiten, with Predictive Whitening™.	Set in the studio, against your NanoChroma™ reading.	The studio times every round.	NanoChroma™ reads it before any gel, and again after.
A dentist's take-home tray.	Chosen at the office, then handed over.	You do, about eight hours a night for about fourteen nights.[7]	A shade guide, matched by eye. Someone looks and decides.
Drugstore whitening strips or a kit.	Fixed low on the pharmacy shelf.	You do, and nobody checks.	Nothing is read. You judge it in the mirror.

How surface stain removal differs from bleaching

Surface stain removal scrubs or tints the outside of a tooth; bleaching changes the colour inside it. In a lab comparison, charcoal and violet toning whitened far less than the professional routes.[5]

What the charcoal and violet products left behind

The charcoal left the enamel with irregularities and grooves, and the violet product left granular deposits.[5]

What role light plays in whitening

Light in a whitening room is for comfort. In placebo-controlled trials of low-level laser in 288 patients, it cut the sting after a session and left the colour change alone.[9]

A teeth whitening machine, UV or LED, is a lamp beside the gel; the peroxide gel is what bleaches. LED kits sold for home use carry a lamp and no instrument, so you never learn your starting shade.

Why some teeth and restorations respond differently

The third lever is your starting colour, and no two mouths start from the same one. Enamel thickness and your own dentine set the pace. Crowns, veneers and bonding do not respond at all, which is why whitening around veneers and bonding is its own question.

Response also slows and then stops. On the shade guide, half of forty adults stopped changing by the third session, while on the finer instrument threshold most were still moving.[4] Only a reading tells you which one you are.

The teeth whitening process at UpWhiten, phase by phase

UpWhiten is the only NanoChroma™ provider in Ottawa. Every session uses a special gel plus nano-hydroxyapatite, the same mineral your enamel is made of.

1. Phase 1, fast whitening: sessions three to seven days apart, as many as your teeth need, until your reading stops moving.
2. Phase 2, past the plateau: unlimited spaced sessions for a year to break that plateau.
3. Phase 3, maintenance: top-ups timed to your teeth, because the interval depends on the person.

At UpWhiten, NanoChroma™ predicts your result before your first session, with 99.98% prediction accuracy. At UpWhiten, clients have gone up to 32.8 shades whiter on the NanoChroma™ scale.

The Ideal Shade Package holds unlimited sessions until you reach your ideal shade or your genetic limit, at no extra cost. A session minute by minute and every whitening option have their own pages. At the Ottawa studio, you see your exact price at the free scan.