The reason for this is that the whitening agents will not act on these. And if it does, then there will be uneven whitening on the teeth. If you are planning to whiten your teeth and at the same time planning for restorations, it is recommended that the teeth whitening procedures should be done first before the restoration. These products that are available here will often contain lesser amount of whitening agents. Or the concentration of hydrogen peroxide for these products is less than what the professionals use. In many counts, the concentration of the peroxide for these products varies from 3 to 6 percent. For this reason, the efficacy and the reliability can be questioned depending on the actual product. The filling is typically composed of the composite resin material which is bonded to the tooth so that the gap can be addressed. But for major teeth issues like wear and discoloration, then the porcelain veneers can be used as the answer. For extreme cases of discolored set of teeth, the porcelain veneer can be used as well. For example, blood that has leeched inside a tooth will discolor it. For these, internal bleaching must be done by a professional. The process is basically the same. A bleaching agent will be placed and sealed inside the tooth that will make its shade lighter given time. Not all teeth are white. The teeth have sixteen varying shades. The results can be realized after a few days, and the white color of the teeth can be maintained for months provided of course that proper maintenance is made. The strips on the other hand are thin strips that are coated with the gel fortified by hydrogen peroxide. These strips are also attached to the teeth twice a day. In fact sales of teeth whitening strips are rising steadily that it is expected to surpass sales of whitening toothpastes soon. The main reason for this is its ease of application, availability and affordability. Teeth whitening strips are a comparatively new addition to teeth whitening for home use.