Before anything else, the advice that costs you nothing: if you think your problem is ordinary surface stain, go and try drugstore whitening strips first.
We mean that. Peroxide is peroxide, and the active ingredient in a strip from the pharmacy is doing the same chemistry as the gel we would hand you. What differs is concentration, how long it stays in contact with the tooth, and how well it is kept there. For a lot of people, strips are enough, and we would rather you found that out for twenty dollars than for several hundred.
This page is about the people for whom that does not work, and why.
First: is it stain at all?
This is the question that decides everything, and it is the one skipped most often.
Bleaching removes stain. It does nothing whatever to a tooth that looks yellow for a structural reason, and there are several.
- Thinning enamel. Enamel is translucent and the dentin underneath it is yellow. As enamel wears or erodes, more of that yellow shows through. The tooth is not stained, it is thinner, and no amount of peroxide changes the color of dentin you can now see. Wear has its own article, because the color is usually the least of it.
- A single dark tooth. Usually a nerve that died, often years after a knock nobody remembers. That is an internal problem and external bleaching will not touch it.
- Internal staining from medication or fluorosis. Tetracycline banding and fluorosis mottling sit inside the tooth, not on it.
- Old restorations. Fillings, bonding, crowns and veneers do not bleach at all. Whiten around them and they stay exactly where they were, which is sometimes a nasty surprise.
The most useful clue is your own history. Whitening that produced very little last time, or that left your teeth looking grayer rather than whiter, points at thinning enamel rather than stain. That is a finding worth having, and it changes the conversation from whitening to what would actually improve the appearance.
Working out which of these you have takes an exam and a photograph, and it is the reason we will not sell you a whitening kit over the phone.
What we use when strips are not enough
We use KöR® Whitening, and in practice we use the KöR ULTRA tier essentially always rather than working patients up through the lighter kits. For the kind of discoloration that brings someone to us after the drugstore version has already failed, starting lower tends to waste a round.
The thing that makes the system different is not a stronger gel. It is how long the gel stays active.
- The trays are made to seal. They are designed to keep saliva out, and saliva is what breaks peroxide down. A tray that leaks is a tray that stops working early.
- The gel is kept cold from manufacture to delivery. Peroxide degrades on a shelf, and a refrigerated supply chain is the unglamorous reason the product performs the way it does.
- It is worn overnight rather than in a chair. Which is where the time comes from.
KöR states around 6 to 10 hours of active whitening per application, against roughly 20 to 30 minutes for a conventional tray. That comparison is credited to Clinical Research Associates and to Dr. Rod Kurthy, who developed the system, so it is not a disinterested source. We quote it because the mechanism is sound and the results in our hands are consistent, not because the figure is independent.
Why we do not offer an in-office-only whitening appointment
You have seen these advertised everywhere: one visit, a light, dramatic before-and-afters. We do not sell one, and the reason is worth stating plainly.
KöR’s own position is that no in-office-only system produces predictable, long-lasting results. That is the manufacturer saying it about its own category. A single session can produce a striking photograph, largely from dehydration that rebounds over the following days, and the color that remains a month later is a different number from the one on the chart at the end of the appointment.
Where an in-office session earns its place is as a boost at the front of a take-home course, not as the whole treatment. Anyone selling you the appointment on its own is selling you the photograph.
Sensitivity, and what actually helps
Sensitivity during whitening is common, it is usually temporary, and it is the main reason people abandon a course halfway.
What helps: not doubling up when you have missed a night, a desensitizing paste used in the weeks beforehand rather than started in a panic afterward, and telling us early rather than pushing through. Severe sensitivity is a reason to slow the schedule down, not a reason to stop, and it is easier to manage before it has become the thing you associate with the trays.
Persistent sensitivity that was there before any whitening is a different conversation, and often a more useful one. That is frequently exposed root surface or worn enamel, and it means the answer was never bleaching.
Whiten before restorations, never after
If there is any chance of bonding, veneers or a crown at the front of your mouth, whitening comes first.
Porcelain and composite do not bleach. Whatever shade your natural teeth are on the day a restoration is made is the shade it gets matched to, permanently. Whiten afterward and your own teeth lighten while the new work stays put, which is how a front tooth ends up no longer matching its neighbor.
Whiten, let the shade settle for a couple of weeks, then match to it. We go through the whole sequence on the cosmetic dentistry page.
How long it lasts, and the part nobody mentions
Teeth do not stay where whitening leaves them, because the things that stained them are still in your life. Coffee, tea, red wine and tobacco all keep working.
What makes a take-home system worth the money is that you keep the trays. Topping up for a night or two once or twice a year holds the result for a fraction of the original effort, and that maintenance is the difference between whitening once and having white teeth.
One timing note worth knowing: do not brush immediately after anything acidic, and that includes the wine. Enamel is softened for a while afterward. Rinse with water and wait. The acid article covers why that matters more than the staining does.
The fuller version
We have written all of this up at length, including how to tell stain from thinning enamel yourself, what the drugstore products do and do not achieve, and what happens with a single dark tooth: Why Won’t My Teeth Get White? →
Where to start
If strips have already failed you, or you have a single tooth that has gone dark, or you want to know whether what you are looking at is stain at all, that is an exam and a photograph rather than a sales conversation. Call 702-734-0776.