Almost every toothpaste states what it protects against and what it brightens. What is almost never stated: how abrasive it is. This is exactly what the RDA value measures, and for many people, it is more important than any advertising claim on the tube.
What the RDA value measures
RDA stands for Relative Dentin Abrasion. It measures how much dentin a toothpaste removes during brushing in a laboratory setting, comparing the result to a reference paste that is assigned a value of 100. A toothpaste with an RDA of 50 removes about half as much as the reference, while one with an RDA of 150 removes one and a half times as much.
The international standard for toothpaste allows values of up to 250. Anything below that is considered permissible, but permissible does not mean it is suitable for every mouth.
Why dentin is the deciding factor
Tooth enamel is the hardest material in the body. Dentin, the layer of tooth substance underneath, is significantly softer. As long as it is covered by enamel and gums, the toothbrush cannot reach it.
This changes when the gums recede and the tooth necks become exposed. Then the toothpaste rubs directly on the soft dentin. Over the years, a highly abrasive paste wears away substance in these areas, causing the tooth necks to become sensitive and potentially develop wedge-shaped defects. It is for this exact case that the RDA value is the most important figure.
RDA value table: how to interpret the numbers
| RDA value | Abrasion | Classification |
|---|---|---|
| 0 to 70 | low | gentle, also for sensitive teeth and exposed tooth necks |
| 70 to 100 | medium | acceptable for healthy teeth in everyday use |
| 100 to 150 | high | not for long-term use, not for exposed tooth necks |
| over 150 | very high | only for short-term and targeted use, e.g., as a polishing paste |
This classification is common, but not standardized. It serves as a good guide, not a fixed limit.
Who should pay attention to a low RDA value
- For sensitive teeth and exposed tooth necks. Here, a low value is half the battle. Read more about this in the article Sensitive Teeth.
- In case of gum recession, even if the teeth are not yet sensitive.
- If you brush vigorously. Pressure and abrasion reinforce each other.
- For crowns, veneers, and fillings. Rough surfaces become discolored more quickly.
Whitening toothpaste and the RDA value
Many whitening toothpastes work by using more or coarser abrasive particles. They remove stains by abrading the surface more heavily. This works in the short term, but in the long run, it is exactly the wrong approach: the enamel becomes thinner, the yellower dentin shows through more strongly, and over time, the teeth appear darker instead of brighter.
Good whitening care therefore relies on fine cleaning particles with a smooth shape and whitening active ingredients, not on abrasion. How to keep teeth permanently white is explained in Keeping teeth white.
The RDA value is not everything
Three things help determine how much tooth substance you remove when brushing:
- Pressure. If you press too hard, even a mild paste will cause damage.
- The brush. Hard bristles increase abrasion. For sensitive teeth and exposed tooth necks, the MINT Sensitive Toothbrush with ultra-soft filaments is the right choice. Which hardness level is otherwise appropriate is explained in Toothbrush hardness level.
- Acid. Immediately after consuming acidic foods, the enamel is softer and reacts more sensitively to abrasion. More on this in Acid protection for teeth.
And a common misconception: a low RDA value does not mean that the paste cleans less effectively. How thoroughly a toothpaste removes plaque depends primarily on the shape and hardness of the cleaning particles, not just on how abrasive it is.
Why the RDA value is so rarely stated on the tube
There is no obligation to disclose it. Many manufacturers have it measured but do not communicate it. If you want to know, ask the manufacturer. A brand that has a low value will usually be happy to tell you.
The RDA value of MINT toothpastes
MINT toothpastes work with the MPT1 Ultra Polish technology developed by Dr. Mintcheva: perlite acts as a fine, smooth cleaning agent instead of coarse abrasive particles. According to MINT, the RDA value is below 37, which is clearly in the gentle range. More about the technology can be found in The basis of all dental care.
For sensitive tooth necks, the MINT Sensitive Toothpaste is the right choice, and for your smile routine, the MINT Hollywood Smile Toothpaste, which brightens without relying on coarse abrasion.
Frequently asked questions about the RDA value
Which RDA value is good?
For the daily care of healthy teeth, a value of up to about 70 is gentle, and up to 100 is acceptable. For sensitive teeth or exposed tooth necks, you should stay well within the lower range.
Which RDA value for sensitive teeth?
As low as possible, ideally below 50. With sensitive teeth, the soft dentin is often exposed, and it reacts most strongly to abrasion.
Where can I find the RDA value of my toothpaste?
Usually not on the packaging at all, as there is no obligation to provide it. Ask the manufacturer or check their website.
Does a toothpaste with a low RDA value clean less effectively?
Not necessarily. Cleaning performance depends primarily on the shape and hardness of the cleaning particles. Fine, smooth cleaning particles can remove plaque thoroughly without removing much substance.
What is the difference between RDA and REA?
RDA measures the abrasion on the softer dentin, while REA (Relative Enamel Abrasion) measures it on the tooth enamel. Because dentin is more sensitive and is directly affected when tooth necks are exposed, the RDA value has become the more important metric.
Professional background: MINT Cosmetics was founded by Dr. Mariana Mintcheva, a dentist specializing in aesthetic dentistry and director of the MINT Dental Spa in Düsseldorf. All advisory content is created based on practical dental experience. It does not replace individual dental advice.
