RDA index of a daily toothpaste is very important!

Our toothpaste choice is important for our dental health!

When choosing a toothpaste, we should pay attention to the value of RDA.

Relative dentin abrasivity (RDA) is a standardised measurement of the abrasive effect that the components of the toothpaste have on a tooth.1 The RDA scale was developed by the American Dental Association (ADA). The RDA scale compares toothpaste abrasivity to standard abrasive materials and measures the depth of cut at an average of 1 millimetre per 100,000 brush strokes onto dentine.2 This comparison generates abrasive values for the dentifrices that would be safe for daily use. In vitro dental studies showed a positive correlation between the highest RDAs and greater dentin wear.3

Since 1998, the RDA value is set by the standards DIN EN ISO 11609. Currently, the claim on products such as toothpaste are not regulated by law, however, a dentifrice is required to have a level lower than 250 to be considered safe and before being given the ADA seal of approval and toothpaste makers should regularly measure their product’s abrasivity. Should be considered that some whitening toothpastes are regularly with very high abrasivity index. Here is RDA score to interpret the RDA values:

 

RDA Score

Level4

0-70

Low: safe for cementum, dentin and enamel

70-100

Medium: safe for enamel, dangerous for cementum and dentin

100-150

High: dangerous for cementum, dentin and enamel

150-200

Very high: harmful limit, damaging for teeth

 

While the RDA score has been shown to have a statistically significant correlation to the presence of abrasion, it is not the only contributing factor to consider. Other factors such as the amount of pressure used whilst brushing, the type, thickness and dispersion of bristle in the toothbrush and the time spent brushing are other factors that contribute to dental abrasion. Pay attention to pressure. Dentists recommend brushing with no more than 150 grams of force (mass). Look at your old toothbrush. If the bristles look splayed, you are brushing too hard.

Sources: 1. Vieira GH, Nogueira MB, Gaio EJ, Rosing CK, Santiago SL, Rego RO. Effect of Whitening Toothpastes on Dentin Abrasion: An In Vitro Study. Oral health & preventive dentistry. 2016 Jun 27, 2. Vieira GH, Nogueira MB, Gaio EJ, Rosing CK, Santiago SL, Rego RO. Effect of Whitening Toothpastes on Dentin Abrasion: An In Vitro Study. Oral health & preventive dentistry. 2016 Jun 27, 3. Macdonald E, North A, Maggio B, Sufi F, Mason S, Moore C, Addy M, West NX. Clinical study investigating abrasive effects of three toothpastes and water in an in situ model. J Dent