*mention: in this article we will present our point of view in accordance with the ISO:11609 standard, the only one approved by the ADA (American Dental Association) and the difference explained compared to other normal or non-approved tests.

RDA is short for radioactive or relative dentin abrasion. To be precise, this complicated-sounding term tells us how much a tooth “abrades” the dentin (i.e. the inside of the teeth) under laboratory conditions. In other words, it refers to the abrasion of tooth substance caused by a toothpaste. Note: the only accredited test is to the ISO:11609 standard being accepted by the ADA in the USA and is performed ONLY after 4000 brushings (stokes) (equivalent to almost 6 months of tooth brushing in a single session).

Caveat: There are normal studies of 1500 – 2000 brushings done consistently that are NOT good as a baseline, but only for marketing purposes, this is a very important aspect to follow in this article.

In a laboratory, the cleaning performance of a toothpaste is tested under standardised conditions against a reference value. Therefore, R often represents the relative abrasion of dentin. At the same time, or alternatively, the term radioactive abrasion of dentin is also commonly used because the tooth structure is irradiated for measurement. This examination is done in vitro, i.e. not on living organisms.

Although the RDA value is probably the best known measure of toothpaste abrasion, it is not found on most toothpastes. There is no requirement to declare the GDR value. The declaration is voluntary and is treated differently by different producers. However, the major criticism of the RDA value and alternative methods such as PCR (Pellicle Cleaning Ratio) or REA (Radioactive Enamel Abrasion) values is that the results from the laboratory cannot be directly transferred into daily use. Many other effects, such as the type of toothbrush or the pressure applied when brushing, also have an influence on abrasion. In addition, the RDA value is measured on dentin, which is not directly transferable to enamel abrasion.

The higher the RDA value, the higher the abrasiveness of the toothpaste and thus the higher the abrasion of the dentin. The RDA table can be roughly divided into five categories:

Under 30: very low abrasivity with minimal cleaning power suitable for baby toothpastes.

30 to 50: very low abrasiveness with a good ratio between abrasion and cleaning effect suitable for daily care of baby teeth in children in particular.

50 to 70: low abrasiveness recommended for those with sensitive teeth and already compromised enamel.

70 to 100: Medium abrasiveness, the ideal value for healthy natural teeth that need daily full care.

100 to 150: High abrasivity, usually whitening or deep cleaning toothpastes.

150 to 250: value considered harmful.

>250: above the recommended ISO and ADA upper safety limit

*Minds: In our view, toothpastes for dental veneers should have an ideal abrasivity between 70 – 120 according to ISO:11609, but unfortunately many companies do not display the exact standard and number of brushes used in determining the RDA in claims.

Example: PRANOYA toothpaste for cosmetic dentistry and natural teeth has an RDA value between 40 – 50 in a normal test performed at 1500-2000 brushings and under the new ISO standard, a study conducted by Intertek UK we have a value of 104 GDR at 4000 brushings, perfectly safe for everyday use and well below the limit allowed by the American Dental Association for the US market or the European market. Manufacturers are NOT obliged to provide this information to customers, but this article is intended to be educational.

Attention!

In Europe, toothpastes with an RDA value of up to 250 are allowed. A toothpaste with that much abrasion would probably damage your teeth after just a few uses.

In general, the value for a toothpaste for daily use in adults should be according to the individual’s teeth. If your teeth are sensitive and have compromised enamel, choose a lower RDA value, if your teeth are healthy and you want to maintain hygiene use a medium value and if you want whiter teeth try a much higher value but be careful not to exceed 150. For dental veneers, the ideal RDA value from our point of view according to the new standard should be between 70 – 120 because at these values, it theoretically provides the ideal in cleaning without compromising but a very important aspect are the ingredients used as agents.

Whitening toothpastes that work by oxidation should be avoided at all costs. However, the RDA value alone does not necessarily determine whether the tooth structure will be affected or not.

What RDA value is actually good for you. or for your children. also depends on a number of individual factors:

Toothbrush: If you use a toothbrush with soft, medium or hard bristles, you should choose a toothpaste with an appropriate RDA value. A toothbrush with hard bristles also contributes to increased abrasion. Especially in the case of children’s toothbrushes, care should be taken to choose a soft one. If electric toothbrushes are used, a toothpaste with a low to medium RDA value is usually sufficient.

Tooth brushing technique: the way teeth are brushed can also influence whether extra enamel is removed. Teeth should be brushed gently and horizontal movements should be avoided to protect teeth and gums. Parents need to be careful and make sure their children are using the correct brushing technique.

Tooth condition: Teeth with hypersensitivity may be a sign that the enamel is already damaged. In this case, it is recommended to use toothpastes with lower dentin abrasion. Patients who grind their teeth (bruxism) also suffer damage to the tooth substance and should be particularly careful when cleaning their teeth.

Baby teeth: the enamel of baby teeth is almost half as thin as that of permanent teeth. Therefore, teeth for babies and young children should also have a fairly low RDA value.

The desired result: To remove stains from teeth, whitening pastes are often used. These are characterized by a higher abrasion value; 100 – 150 RDA being safe but those with a value between 150 – 250 RDA can only be used with a doctor’s recommendation (in our view) and are usually not recommended daily and never very long term.

Most of the information in the public domain is incomplete or misunderstood. In order to make education as good as possible, we need to present correct information to our customers. We like to think that we always call a spade a spade and that’s why we have an extremely high satisfaction rate from our customers.

You can always view the summary of the tests or clinical studies carried out on our products by accessing the Clinical Studies section and for professionals who want to find out more about the commercial relationship with our company, they can request access to the dedicated page.