What about the long lasting effect of teeth whitening gel? It seems to be long enough. When used as a take-home product, it will have effect within one month. In the majority of cases, the teeth whitening gel treatment is long-lasting. But, remember that coffee, smoking, red wines and some medicine products will darken teeth little by little again over time. After the initial treatment, the effect lasts about 3-6 months. Your safety methods:
Never use teeth whitening gel more than 35% hydrogen peroxide or carbamide peroxide concentration! All teeth whitening gels are effective in whiten teeth. The final results from a higher concentration gel are not better. Beyond controversy, it may be faster but not safe, keep in mind: in the end result is the same. So you will get the same result with 16% as you can with the 22% it will just take a bit longer. Rely upon it. It is easier to wait some more days, than suffer from fewer side effects. Above 22% concentrated teeth whitening gels can damage your gums permanently. Always read specification with all your eyes!
Gels over 35% are used in dental offices only. These are professional products and should be used under the care of a specialist. When you are going to use any teeth whitening product, make sure first, the gel does not injure the gums.