With the awareness of how important one's own oral hygiene is, the sensitivity to the ingredients of a toothpaste and its other properties, especially the so-called abrasiveness, also increases. In discussions with our customers, we are increasingly asked about the so-called RDA value. RDA stands for “Relative Dentin Abrasion” and indicates how strongly the paste can remove tooth structure. Where the name comes from, what the value means and why it doesn't measure up. For everything that should be considered when choosing a toothpaste, read the following article.
Abrasive substances in toothpaste
It is probably clear to everyone that toothpaste is indispensable for daily oral hygiene. Toothpaste prevents tooth decay and gum inflammation thanks to the care ingredients it contains and removes food residue, plaque or even superficial discoloration. The cleaning performance is determined by so-called abrasives in the toothpaste. They are indispensable components of toothpaste, but on the other hand they can also be partly responsible for the removal of tooth structure. The cause of such defects is usually a combination of incorrect tooth brushing technique and greater abrasiveness of the toothpaste, which should be recognizable by the RDA value.
The RDA value of a toothpaste
Although the measurement of the RDA value and thus the abrasiveness of a toothpaste is or should be carried out according to an ISO standard and therefore according to a prescribed protocol, the values should be viewed as comparative values. Although the measurement process is standardized, not all steps are described in detail. For example, the duration of the individual steps may vary or the type of brushes with which the test is carried out.
To determine the RDA value of a toothpaste, tooth roots are first irradiated with high energy, causing the phosphorus atoms of the tooth tissue to become radioactive. This process is necessary for later measurements. The irradiated tooth roots are then fixed in a type of brushing machine and brushed with both a standardized comparison paste and the toothpaste to be tested. The amount of tooth substance removed is determined by measuring the radiation activity in the toothpaste foam. The higher the radiation, the more tooth substance was removed and the greater the abrasiveness. To obtain the numerical value, the value of the standardized comparison paste is set equal to 100 and the abrasion of the test toothpaste is expressed as a percentage of this standard value. This percentage is then the RDA number. So if the toothpaste has an RDA value of 50, this means that it is only half as abrasive as the standard toothpaste used.
The following table, which compares the most important parameters of RDA measurements in Indiana, USA and in Zurich, Switzerland, shows how different the parameters and consequently the results of RDA measurements can be: < /p>
Source: PROPHYLAXEdialog, special edition RDA
In addition, the RDA value is usually not printed on the packaging anyway or there is no information about which laboratory it was measured in. The RDA value can therefore only be a guideline and should not be the only criteria when choosing a toothpaste. In principle, toothpaste with an RDA value of up to 170 (RDA Indiana) is suitable for daily use.
RDA values are not the benchmark. of things
Apart from the ambiguity of RDA values, it is worth mentioning that damage to the teeth rarely comes from an abrasive toothpaste alone. Incorrect brushing technique, e.g. vigorous scrubbing during brushing or brushing your teeth immediately after consuming acidic foods, or even using a hard toothbrush are a factor that should not be underestimated when it comes to damage to tooth structure. In addition, toothpastes in the EU are subject to the Cosmetics Regulation and may not be harmful to health when used as intended.
If your toothpaste has an RDA value printed on it, a maximum value of 100 is a recommended limit for healthy, undamaged teeth. If you are looking for a toothpaste with a lower RDA value, please contact us. In principle, you will not find any toothpaste in our online shop that is not suitable for daily use twice a day.