Consider tooth bleaching if your teeth are darkened from age, coffee, tea or smoking. Teeth darkened with the color of yellow, brown or orange respond better to lightening. Other types of gray stains caused by fluorosis, smoking or tetracycline are lightened, but results are not as dramatic. Consult your dentist, who will determine whether you are a candidate for tooth bleaching and what type of bleaching system would provide the best results: home or office bleaching, or both.
In our office we use Philips Zoom! WhiteSpeed, the latest and most effective tooth bleaching method. Zoom! WhiteSpeed whitens teeth effectively, with minimal or no sensitivity at all. For optimal results we recommend the in-office chairside bleaching to be followed by at-home bleaching (dual protocol) with the corresponding materials we provide you.
Mode of action
Light-activated technology accelerates results – maximum results in minimal time
The shade of a patient’s teeth is the result of organic colour molecules within the otherwise whitish materials which make up the dentine and enamel. These molecules are coloured because they have sections called chromophores that absorb certain wavelengths of light, and reflect others
The colour arises from a long chain of alternating carbon single and double bonds within the chromophore, which can absorb light energy. The length of this chain determines the colour that is absorbed – the longer the chain, the longer the wavelength which is absorbed, and the stronger the colour.
Applying hydrogen peroxide breaks double carbon bonds within the chromophore making the teeth appear whiter. This disruption of the double bonds in the chain disrupts the conjugation length, and it is now so short that the molecule appears colourless. The stains have in effect been “decolourised”.
The importance of basic colour theory
- When light shines on an object some colours are reflected off the object and others are absorbed by it
- Our eyes only see the colours that are reflected
- Complementary colours on the colour wheel absorb the opposite colours light most strongly – so for example yellow absorbs blue
Chromophores in tooth stains absorb blue light, which is why they appear to be yellow/red.
Accelerated whitening results with the Philips Zoom! blue light
Since blue light is quite naturally absorbed by the yellow-red stains in the tooth, we make use of this energy in the whitening process. The electrons in the in chromophore are excited to a state of increased energy by the natural blue light absorbtion. “Excited” chromophores react with the hydrogen peroxide radicals far more rapidly and thoroughly than they would otherwise do, decolouring the molecule in much the same way, only much more effectively. Note: these reaction steps effectively occur simultaneously
Using the WhiteSpeed lamp adds energy to the molecules, speeding up the reaction.
Sceptical?! - This photochemical principle is actually very similar to that used in standard blue light cured dental restoratives. In that case, added yellow pigments in the bonding resin absorb blue light in just the same way, but the light energy is now purposefully directed into reactions which cure the resin rather than into self-reaction with bleaching agent.
Impressive results fast!