RDA VALUES FOR BRUSHING YOUR TEETH WITHOUT DAMAGE TO GUMS AND/OR ENAMEL
Most toothpaste on the market contains abrasive particles (i.e. particles which are not water-soluble) including aluminum hydroxide, silicates and others. Such "scrubbing" compounds are added to help remove plaque and stains during brushing, and it's their quantity, particulate size and hardness which determine the degree of abrasiveness of a toothpaste.
To be able to measure a toothpaste abrasiveness, scientists use the RDA index (from radioactive dentin abrasion or relative dentin abrasion). Higher values indicating increasingly higher abrasiveness. The more abrasive power, the more likely enamel erosion will occur, which can easily open the way to tooth decay. It's typically whitening toothpastes which top the list of abrasiveness while toothpastes formulated for sensitive teeth tend to be at the bottom.