Synthetically produced amorphous silicas are often the favoured abrasive component in oral compositions and can be readily tailored during the production process to possess predetermined abrasive and other physical characteristics appropriate for use in oral compositions. This correlation between the values of cleaning power and abrasivity (expressed as RDA value-Radioactive Dentine Abrasion test value) for abrasive systems was used as the basis of accepting RDA as the monitor of the cleaning power of an oral composition. 6, 1987, pages 248-249) it is stated that as dentifrice abrasiveness increased, less stained pellicle formed on clean teeth and more stained pellicle was removed from pre-stained teeth.
Precipitate silica series#
So, in Morton Pader's textbook “Oral Hygiene Products and Practice” (Cosmetic Science and Technology Series vol. By corollary, it is also generally accepted that any reduction in abrasion from a cleaning composition will cause a fall in cleaning performance. This is particularly undesirable when that surface is the surface of a tooth. The rate of enamel removal should not exceed the rate of natural replenishment through remineralisation.Ī general problem with abrasive cleaning systems, and toothpaste abrasives in particular, is the proportionate relationship between cleaning and abrasion: it is accepted that any change in the nature or amount of abrasive in a composition that leads to improved cleaning will generally also lead to higher abrasion of the surface to be cleaned. This abrasiveness must be kept at a sufficiently low level that the surfaces of teeth, particularly dentine, are not permanently damaged by daily brushing regimes. In order to achieve cleaning, it has been generally accepted that the abrasive must provide a certain degree of abrasiveness of the tooth surface. More recently synthetic silicas have been adopted because of their efficient cleaning, compatibility with other ingredients and other physical properties such as refractive index. Commonly used abrasives are aluminas, calcium carbonates and calcium phosphates. Abrasives are formulated into toothpastes as the main cleaning agent. They are used to aid in the removal of food particles, staining and bacterial films from the surfaces of teeth. Oral compositions, such as toothpastes, are well characterised in the literature and many compositions are disclosed in patent specifications and other literature. The invention also relates to processes for preparing the abrasives and to oral compositions, such as toothpastes, which clean teeth without excessive abrasion of dentine or enamel. This invention relates to precipitated amorphous silica particles of use, for example, as abrasive agents in oral compositions.
0 kommentar(er)
