RDA Score Level [24] 0-70 Low abrasive: safe for cementum, dentin and enamel 70-100 Medium abrasive: safe for enamel, dangerous for cementum and dentin 100-150 High abrasive: dangerous for cementum, dentin and enamel 150-250 Very high abrasive: harmful limit, damaging for teeth 250 and above Not recommended