All whitening methods are effective, each with specific advantages and very few or no disadvantages. The key is that regardless of the method used, the result will last for many years if the patient follows some basic principles.
The most important of all is brushing the teeth. This should be done with a medium toothbrush, which should be in good condition, meaning it should be replaced frequently or when the bristles show wear. Electric toothbrushes give even better results.
Another important parameter for maintaining whitening is gum health. The use of a mild mouthwash is recommended to keep the gums free from inflammation and gingivitis.
Toothpaste also plays a significant role. We prefer pharmaceutical toothpastes as they are more specialized and of better quality.
Finally, limiting smoking helps maintain whitening, while coffee and red wine have been shown not to affect the result as long as the above practices are followed!