The increase in the number of over-the-counter products that claim to have "tooth-whitening" properties, and the emergence of new treatment methods directly available to the public, give rise to a number of questions.
This definition, given in the European Council Cosmetics Directive 76/768/EEC, equates with the claims of a range of tooth bleaching products. The Directive defines the composition, labelling and packaging regulations applicable to cosmetics, and very clearly distinguishes cosmetics from medical devices.
Annex III of the Directive provides the “list of substances that cosmetic products
It is these rules that the United Kingdom puts forward to forbid the importation, selling or distribution on its market of any products that contain or may releasemust not contain except subject to the restrictions and conditions laid down” for each category of product. The list includes "hydrogen peroxide, and other compounds or mixtures that release hydrogen peroxide, including carbamide peroxide and zinc peroxide”. The maximum hydrogen peroxide concentration currently authorised for cosmetics is "0.1% of H2O2, present or released". There are no requirements for specific conditions for use or particular warnings to be printed on the label. more than 0.1% hydrogen peroxide, which the UK refuses to recognise as medical devices. However, the local authorities (Department of Trade and Industry, Department of Health) seek amendments to Directive 76/768/EEC so that British practitioners may meet their patients' demands (Morris, 2003).
As for the few products that do contain a bleaching agent, the limited active compound concentrations imposed by law make their therapeutic efficacy questionable. It is impossible from the documentation provided to have a clear view on this matter, as there are always many significant biases (patient selection criteria, absence of test group, objectivity of measures...).that claim to have tooth-whitening properties, including certain toothpastes (Table 5), rarely contain hydrogen peroxide or one of its precursors, or even for that matter any other kind of bleaching agent. Their main whitening effect results from the action of the abrasive elements they contain, which remove superficial extrinsic stains. Some manufacturers take the precaution of reassuring their customers on the safety of their products and insist on their low abrasiveness. Unfortunately, this point is difficult to prove from the various documents available, as the abrasive power of the products in question is rarely indicated. "New generation" toothpastes do however seem to contain cleaning agents that do not increase their abrasiveness. Nevertheless, in view of the lack of information available, it is advisable to use these toothpastes in alternation with less abrasive ones, as the regular use of a highly abrasive toothpaste may cause a roughening of the tooth surface that will encourage the deposition of new pigments (Clergeau-Guérithault et al., 2002).