Teeth Whitening: Effect, Risks and Durability
How bleaching works, what side effects are possible and how long whiter teeth last.
White teeth are at the top of many people’s wish lists. Bleaching can lighten the colour of your teeth noticeably – but it is only safe if your teeth are examined first and the treatment is carried out professionally.
Bleaching gels containing hydrogen peroxide or carbamide peroxide penetrate the tooth enamel and break down embedded pigments. The most common side effect is temporary sensitivity. Depending on lifestyle, the result usually lasts one to three years. Fillings and crowns do not lighten.
Possible side effects
- temporary sensitivity to cold and touch
- irritation of the gums if gel gets onto them
- uneven lightening where there are spots or fillings

Tips for a long-lasting result
- avoid strongly staining foods (coffee, red wine, curry) for the first 48 hours
- regular professional teeth cleaning
- do not smoke
- top-up treatments as agreed
Products sold over the counter may only contain very low concentrations of the active ingredient. Products from dubious sources can damage teeth and gums.
Book your appointment at the Zahnarztpraxis St. Peter – via online booking or by phone on 0911 554181. You will find us at Hainstraße 25, 90461 Nürnberg (tram 6/10 to Scharrerstraße, patient parking via Scharrerstraße).
Frequently asked questions
Does activated charcoal toothpaste help?
It tends to remove surface stains and, because it is abrasive, can attack the tooth enamel. We advise against it.
Can I have my teeth whitened during pregnancy?
We advise against it – please wait until you have finished breastfeeding.
This article is a translation of our German guide and does not replace a personal examination and consultation. If you have symptoms, please see a dentist – for example at the Zahnarztpraxis St. Peter in Nuremberg.
