Firstly, the cause of discoloration resulting in the need for dental bleaching may be either internal or external. External discoloration is the color change of the enamel which is the outer layer of the tooth. These color changes can be local or widespread. The reasons can include wrong and/or incomplete brushing and selecting the wrong toothbrush. Foods that contain colorants as well as habits such as too much consumption of cola, coffee, tea or cigarette smoking are also among the reasons for such discolorations. Typically, this type of discoloration, i.e. color changes in tooth enamel disappear after airflow or polishing procedures following tartar removal.
The use of antibiotics that belong to the group of tetracycline during the developmental phase is one of the reasons of internal discoloration. Certain diseases causing increased fever during the developmental phase can also result in color change. Additionally, discoloration can also be the case when canal and filling materials are not adequately removed from the pulp chamber after root canal treatment. This can lead to dark brown discolorations on the teeth. Contrary to common belief, the color of our teeth is not determined by the enamel, the far exterior layer of the tooth but the dentin tissue which is located underneath.
Dental bleaching procedure involves oxidization of the organic tissues on the dentin layer. The procedure uses agents containing hydrogen peroxide. The amount of hydrogen peroxide contained in the ingredients can vary depending on home or office type bleaching agents. While the type of agents used at home with nighttime plates under dentist’s control contain 10% to 15%, the amount in office type agents used in the clinic can be as high as 35%. Therefore, office type bleaching can yield faster results. These can be applied separately or used as a combination. Bleaching at the clinic usually takes around 45 minutes.
Sensitivity occurs typically on day one after the procedure. Sensitivity gradually decreases over the next days. However, it may take longer in patients who have chronic sensitivity before the procedure. Sensitivity can be tolerated with the use of fluoride applications or desensitizing toothpaste. After bleaching, teeth become more sensitive to dyestuffs. Teeth can preserve the white color for many years if patient is careful when using these substances.