Toothpaste Abrasiveness (RDA)

Main article: Teeth

How the abrasion level is measured

The abrasiveness of toothpastes is measured by determining the abrasiveness index (RDA - Relative dentin abrasivity, a method adopted by the American Association of Dentists), using a standardized method consisting in treating a tooth paste whose dentin is treated with radioactive radiation. After brushing the tooth, a suspension is formed containing radioactive particles wiped from the surface. The more such particles, the greater the abrasiveness. In the original, this method was not intended to compare toothpastes, and was used to compare substances compared to a substance having a reference value of RDA = 100. As a result, laboratory tests of toothpastes occur under much harsher conditions than in real life and do not take into account, for example, the presence of a protective layer on the teeth - a pellicle that prevents abrasion of teeth when brushing. Another measurement method is profilometry.

Association of abrasion and wear of tooth enamel

Until 2008, no tooth damage due to abrasive effects of toothpastes was recorded. At the same time, there are studies in which no differences were found in the use of pastes with RDA 90 and 204. Thus, there may be no direct correlation between RDA and enamel wear under real-life conditions.

The wear of enamel depends on a huge number of factors; So, soft bristles, although less traumatic in relation to desen tissues, wear enamel more than hard.

Abrasiveness is measured in numerical values starting from zero according to DIN EN ISO 11609. According to the accepted ISO standard, toothpastes whose abrasiveness (RDA) is less than 250 are considered safe for constant human use throughout life. Abrasiveness is achieved by including silicone, calcium carbonate, sodium metaphosphate, and other components in toothpastes.

The most effective mechanical removal of the raid is achieved at RDA values ​ ​ above 100. Toothpaste, which has low abrasiveness, can less effectively remove dental plaque, since it is formed by biofilms resistant to mechanical effects. At the same time, the remains of biofilms containing pathogens can serve as nutrients for unsalted pathogens (the so-called necrotrophic growth occurs), which can aggravate their settlement of tooth surfaces. In this case, additional components having action on biofilms and antibacterial properties are usually introduced into the composition.

Widespread belief that only toothpastes with RDA are safe for use<150, является в корне неверным и не основано на научных фактах и установленных стандартах.