SEM image of a tooth surface with bacterial tooth discoloration
Tooth discoloration is the result of various dyes and pigments attaching to the organic matter of the tooth. To remove this discoloration,
two methods are usually used: physical removal and
Physical removal aims to remove superficial discoloration
by using an abrasive method (e.g. with ultrasonic tips, sandblasters or
polishing instruments) during a professional teeth cleaning at the dentist from
(costs 90-200 euros).
Chemical bleaching, on the other hand, acts on both superficial and - embedded in the enamel - discoloration and is therefore the most common and effective method of tooth whitening to restore the natural white color of the
In so-called "in-office bleaching", a dentist or his assistant carries out professional teeth whitening in the doctor's office. A highly concentrated bleaching gel (usually based on peroxide) is applied to the teeth and activated using a special UV light.
A weaker concentrated bleach is used by the patient at home
. Here, too, (older) peroxide-based methods are often used, mostly in the form of splints or sticks, which can be individually adapted by a dentist or can be purchased pre-packaged in pharmacies or by mail order
peroxidfreies PAP+ in Gelform
More modern home bleaching procedures are free of peroxide, are used without individual splints and achieve the same or better whitening results.
The active ingredient used here is phthalimidoperoxycaproic acid (PAP), which at the same time reduces tooth sensitivity and protects the gums through the addition of hydroxyapatite and potassium citrate. We then call it PAP+ (including other stabilizing additives).
The costs here are under 50 euros (without rail) and for UV-activated assembled rail kits around 100 euros.
When using peroxide-based bleaches, oxidation occurs through a reactive oxygen molecule. This process is relatively unspecific and undesirably takes place everywhere and especially when it comes into contact with the sensitive oral mucosa: electrons are withdrawn from the phospholipid layer, holes are torn in the surfaces in order to dissolve the discolouration in the teeth
When using the more modern PAP+ bleaching gels, an epoxidation reaction takes place. This type of oxidation takes place in a quasi-different chemical "space", no longer targeting human cells and therefore acting selectively more specifically on the discoloration molecules.
The duration and effectiveness of the bleaching process depends on various factors, including the type and severity of discoloration and the chosen bleaching method.
Tooth whitening through chemical bleaching oxidizes stains and changes the molecules responsible for maintaining color.
Put simply, the bleaching agents penetrate the enamel and break down these molecules into smaller, simpler forms. The smaller the molecules, the lighter the color, resulting in an overall whiter appearance of the tooth.
Common bleaching agents include hydrogen peroxide, carbamide peroxide, and phthalimidoperoxicaproic acid (PAP for short).
rendered model of color particle splitting during bleaching