Dental Bleaching
The basic principle of dental bleaching consists of removing the discolouration in the tooth structure, caused by natural ( free radicals) or acquired (tea, coffee, red wine, etc) colouration, with a chemical product that can break down the molecules responsible for the discolouration.
The most commonly used product is Hydrogen Peroxide, or its precursor, Carbamide Peroxide. In both cases, the final chemical breakdown produces H2O, O2, by combining the bleaching agent with the free radicals in the molecules, there is a break up of the free radical chain which alters the colour.
In the 1960's, professor Torrès from Madrid, Spain, introduced the bleaching technique for vital teeth. consisting of fabricating a metal mould that perfectly adapts to the patient's teeth, from the impression taken by the dentist. After protecting the gum, the mould was inserted around the teeth.
In the 1970's, Professor Goldstein from Georgia, USA, adapted this approach. The gum is protected and the teeth isolated with the use of a dental rubber dam. Gauze imbibed with 35% liquid Hydrogen Peroxide covers the tooth surface. A halogen light placed at a distance of 50 cm directed the heat to activate the bleaching product.
Since 1990 the dental professional carefully protects the gum with a barrier, and covers the teeth with a gel of 35% Hydrogen Peroxide containing a photo chemical initiator (Camphor Quinone). The light activates the initiator that produces the energy to break down the Peroxide. Heat is not required and the sole source of energy being the adequate wavelength emitted by the light located at a distance from 10 to 50 centimeters away from the gel. The gel is renewed at certain intervals. The total procedure time is about 40 to 60 minutes. The chairside session lasts 60 to 90 minutes.
Before Dental Bleaching
