 Dentists consider the extra abrasion of dentin from brushing multiple times per day to be insignificant, since modern toothpastes have Relative Dentin Abrasivity below 250.
<fluency>  Dentists consider the extra abrasion of dentin from brushing multiple times per day to be insignificant, since modern toothpastes have Relative Dentin Abrasivity below 250.
 Dentists consider the extra abrasion of dentin from brushing multiple times per day to be insignificant, since modern toothpastes have relative dentin abrasivity below 250.