The dentin is the primary determinant of tooth color. Acceleration of the oxygenation process using a curing light or laser may cause the peroxide to break down too rapidly. This may reduce the efficiency of enamel penetration. When this occurs, additional applications are needed. Ultimately, the original shade of tooth structure and the desired tooth shade determine how many treatments are required.
Cost can be quite variable.
Laser whitening is more costly than bleaching with trays because the laser equipment is extremely expensive. Costs will vary depending on where you live and the number of teatments you require. If you have prolonged take-home bleaching, such as for tetracycline stained teeth, the cost may be slightly higher. Before you run to your local drug store to buy a cheap home bleaching kit, you should know the main advantages of having your teeth professionally whitened by a dentist. Custom bleaching trays fabricated in a dental office hold the bleach closer to the teeth and will not allow bleach to irritate the gum tissue.