What whitening can and cannot fix
Whitening works well on extrinsic staining — the surface discolouration built up from tea, coffee, red wine, tobacco, and time. It works reasonably on mild yellowing of the natural tooth shade.
It does not change the colour of crowns, veneers, or composite fillings. If you have a crown on a front tooth, whitening the teeth around it will make the crown stand out more, not less. It also works poorly on grey discolouration from tetracycline or from a tooth that died after trauma — those usually need veneers or internal bleaching instead.
This is exactly why we check before treating. Paying for whitening that cannot work on your particular staining helps nobody.
Cleaning first, whitening second
A professional clean removes plaque, tartar, and a meaningful amount of surface staining on its own. A number of patients who come in asking about whitening are satisfied with the result after a scaling and polish alone, at a fraction of the cost.
Whitening gel also penetrates unevenly through a layer of tartar, so cleaning first produces a more uniform result regardless.
In-clinic versus take-home
In-clinic whitening uses a stronger gel with your gums carefully isolated, and is completed in one appointment of roughly 60 to 90 minutes. Take-home kits use custom-made trays and a milder gel worn for a set period over one to two weeks — slower, gentler on sensitivity, and easier to top up later.
Both reach a comparable end point. The choice usually comes down to how quickly you need the result and how sensitive your teeth are.
Sensitivity and how long results last
Temporary sensitivity to cold during and shortly after whitening is common and settles within a day or two. Tell us if you already have sensitive teeth — we can adjust the concentration and use a desensitising agent.
Results typically hold for one to two years, but this depends heavily on your habits. Regular tea, coffee, or tobacco will re-stain teeth faster. Whitening is not permanent, and any clinic promising otherwise is overselling.