Teeth whitening pens, no matter what the brand is, have some common characteristics. They are applicators that store bleaching materials meant to make the teeth appear whiter. The teeth whitening gels’ main ingredient is carbamide peroxide or hydrogen peroxide. These substances work by impacting on the teeths’ dentin layers.
What causes the teeth to become discolored is the breakdown of enamel. This part of the tooth is made up of microscopic rods that are used to protect the tooth during chewing and other stresses caused by everyday activities. As the years go by, the enamel is worn down and becomes more transparent. The yellow color of dentin, which is found at the core of the tooth, begins to show. The kind of food that is eaten can also be a factor. Tea, sodas, and other dark colored foods and beverages can cause the teeth to turn yellow or light brown.
The application of the teeth whitening gel on the enamel of the tooth allows it to be absorbed deep within until it reaches the inner dentin layer where the food stains are normally found. However, it should not be allowed to linger longer than the amount of time indicated by the manufacturers. Otherwise, the peroxide may damage the outer layers of the skin. It should be noted that the degree of effectiveness is different in each case. The results would depend on how discolored the teeth were to begin with and the whitening gel itself.