Teeth whitening: what results are realistic and how long they last
Whitening lightens the natural colour of your teeth by two to four shades. It does not change the colour of fillings and crowns, and that changes the order in which things should be done.
The active substance, hydrogen or carbamide peroxide, penetrates the enamel and breaks down the pigments accumulated over years of coffee, tea, red wine and tobacco. It does not paint the tooth, it reveals its underlying colour.
This is where the most common disappointment comes from
Tooth-coloured fillings, veneers and crowns do not change colour. If you have a visible filling on a front tooth, after whitening it will look darker than the rest, because the tooth around it got lighter while the filling stayed the same.
How long it lasts
Between one and three years, depending on what you consume and whether you smoke. The first 48 hours matter most: the pores of the enamel are open, and coffee, red wine and tomato sauce settle straight in.
Sensitivity after whitening is normal and passes in two or three days. A toothpaste for sensitive teeth, started a week before, reduces it considerably.
Frequently asked questions
Does whitening damage the enamel?
No, not at the concentrations used professionally and with the gums protected. The risk comes with kits bought online, applied without gum protection and without a prior assessment.
Can any tooth be whitened?
No. A root-treated tooth that has darkened from the inside does not respond to external whitening and needs internal whitening or a veneer.
How long does a session take?
About an hour at the clinic. A professional cleaning is done first, otherwise the substance acts on tartar instead of enamel.
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