What is Dental Bleaching?

There might be two confusing terms in this situation. One is for bleaching and the other is Teeth Whitening. Both of these terms whitening and bleaching are interchangeably used but you need to keep in mind that there is a slight difference between the two. Tooth whitening is a process that helps in the restoration of the natural white colour of the tooth by the removal of the stains from the surface of the tooth. On the other hand, Dental bleaching refers to the process of whitening of the tooth beyond its natural colour that is bleaching makes the tooth lighter than its colour which was naturally present.

Bleaching with Lasers

With the advancement of the laser technology in the field of Dentistry, bleaching of the tooth with the help of lasers has become one of the most common affairs in the recent times. Lights emitted from the laser actually enhance the oxidising effect of hydrogen peroxide and this is exactly what is done during the course of tooth bleaching. Thus, hydrogen peroxide is used as the bleaching agent in this case. This process of bleaching with the help of lasers and hydrogen peroxide is also referred to as power bleaching.

Lasers and Its Possible Interaction with the Target

The light from the laser can have a total of four interactions possible with the target tissue depending solely on its optical properties which are as listed below.

• The first one is the absorption of the laser energy by the target that is intended.
• The second possible interaction is the transmission of the laser energy through the target.
• Then comes the reflection of the laser beam from the surface of the target with actually no effect on the target.
• The final possible interaction is the scattering of the spreads of the laser light across a number of directions which results in the weakening of the intensity of the energy of the laser light at any of one point.

Now, in the process of tooth bleaching, the absorption of the laser light energy in the bleaching agent or gel is required. The bleaching agent hydrogen peroxide which is used in this case is optically clear which makes its ability to absorb the visible wavelengths of light very low. But on the other hand, it has the ability to absorb ultraviolet, middle infrared and far infrared light which results in its breakdown.

Mechanism of Laser Assisted Dental Bleaching

Laser-assisted bleaching along with the use of reactive oxygen species like hydrogen peroxide or any derivation of hydrogen peroxide results is a chemical process which takes place by the oxidative decomposition of the chromophores or the colouring agent which in turn allows hydrogen peroxide to absorb visible laser light or near-infrared laser light to an extent. When the chromophores are broken down of these of these coloured organic molecules that absorb light. The light energy is absorbed by the target molecules result in the bleaching of the tooth by the removal of the stains from its surface efficiently and effectively at the same time.

Authored by DR.NIRANJAN P