You saw it with George Clooney in the movie “First I marry you and then I ruin you”, Power Bleaching is a very popular cosmetic dentistry technique in the United States that allows you to regain a young and brilliant smile after just one session.
Fault or merit of the Hollywood celebrities and their dazzling smiles, today the teeth are the business card of the person: it is not enough to have straight and well positioned teeth to feel safe, color and brightness are also part of the game. Today with dental whitening you can regain a bright white smile, from your trusted dentist but also at home with “do it yourself” methods.
At the dentist you will be guaranteed to achieve the highest possible whitening, a minimum time commitment and absolute protection from unpleasant unwanted effects such as excessive thermal sensitivity and gum irritation. The cost of a “from home” treatment lies in the cost, obviously lower than the most effective professional techniques. But the lower effectiveness of the latter makes the effects of the applications very limited and the return to the previous state can occur in a short time. A professional whitening can be performed in the office and at home, with professional methods that make use of whitening agents with a high percentage of active ingredient, capable of modifying the genetically determined color of the teeth, the one that mother nature has provided us from birth, and the variations that the enamel undergoes over time due to the absorption of pigments by its organic components. Furthermore, professional techniques are able to make positive changes even in complex cases where the color of the teeth has been altered by the intake of tetracyclines or excess fluoride, or by congenital causes. The most advanced professional techniques, performed under the supervision of the dentist, can be carried out at home “Home bleaching”, or directly in the office, also known as “Chair whitening”.
For home treatment, the dentist, after an accurate preliminary visit aimed at excluding contraindications such as caries and gingivitis, delivers to the patient special customized soft silicone masks, reproducing exactly the shape of the arches, without invading the gum, inside which a correct quantity of gel with a high percentage of active ingredient, before applying them on the teeth. With the use of the most effective products it is possible to obtain the whitening effect with a significantly reduced application time. It is no longer necessary to wear the masks all night for several weeks but on average one hour of application per day is enough for 5/6 days.
For the treatment in the studio, a high percentage of hydrogen peroxide is used, around 35%, self-activated or photo-activated. In this case, once the gums have been protected, a viscous gel is applied to the teeth and exposed to the light of special lamps capable of accelerating the penetration effect of the whitening substance contained in the gel and the breaking of the bonds inside the molecules. of pigment.
In cases of teeth whitening with more intense colors, it may be advisable to repeat the procedure in the office once or twice, or to combine the treatment in the chair with home treatment.
The risks of a well-performed professional treatment are practically nil, both hypersensitivity and gingival irritation, potential side effects, are eliminated by strictly adhering to the indicated protocols, and in any case, should they occur, they are generally minimal and transient.
Power Bleaching, on the other hand, provides, in addition to the use of hydrogen peroxide (from 15 to 38%), also the use of an energy source to catalyze the reaction. Compared to other chairside treatments without photoactivation, lower concentrations of hydrogen peroxide can be used with the advantage of lower dentinal sensitivity.
Generally the hydrogen peroxide in this type of procedure is in the form of a powder that is mixed at the time of use with an activator gel to ensure maximum chemical stability. The activator gel, in addition to containing the polymers that improve its thixotropic properties, also contains specific photoinitiators or photoactivators based on the type of energy source used which, by absorbing particular wavelengths, activate and accelerate the breakdown of the peroxide. of hydrogen in its by-products (these substances are covered by trade secret and each manufacturer has its own). In addition, weak bases are often present as ionization of buffered hydrogen peroxide with a pH between 9.5 and 10.8 produces more HO-2 perhydroxyl free radicals. The result is more than 50% of the whitening effect in the same time compared to other pH values.
As far as the energy source is concerned, this can derive from a halogen lamp, ultraviolet light, LED, plasma or a laser.
Depending on the source used, the dentist must follow a protocol that depends on the exposure time, the intensity of the light (mW / cm2), the wavelength and of course the photoactivator or photoinitiator contained in the whitening gel.
To go into detail for a moment, there are mainly two photo-catalytic mechanisms that release different free radicals inside the gel: one photochemical (short wavelengths, photons with high energy) and one photothermic (long wavelengths, photons with less energy but with more thermal effect), depending on the predominant one, different quantities of radicals are generated.
At the present state of knowledge we still do not have the answer as to which of the two wavelengths is more effective and all the mechanisms of action are not yet perfectly known.
The whitening lamps are equipped with a particular crystal that diffuses the light simultaneously to both arches (full-arch) and some also have the possibility of mounting a smaller tip for the polymerization of composite resins. Naturally, they have specific software that allow the light to be delivered according to predetermined power and time cycles, so as to alternate periods of emission with periods of non-emission so as not to overheat the tooth excessively. In addition, some of these lamps are “cold light” as they have special filters which, by eliminating long wavelengths, bring light to the tooth surface that does not overheat the pulp, allowing them to carry out continuous emission cycles.
Recently, a technique has been proposed which involves the activation of a reaction initiator by an ultrasound source, but to have the same result compared to that of traditional energy sources it is necessary to continue the treatment for a few days at home.