The toothpaste abrasiveness (RDA) charts circulating online contradict each other — sometimes by a factor of two on the same product. 3M's own technical profile measured Clinpro 5000 at 62.15 and PreviDent 5000 Booster at 112.03 head-to-head; one widely shared chart lists Clinpro at 125, another lists the Booster at 42. They cannot all be true. Here's how to tell verified numbers from copied ones — and when the number matters at all.
RDA — relative dentin abrasivity — is a laboratory measure of how much root-surface material a paste removes under standardized brushing. Most charts you'll find are undated compilations mixing manufacturer literature, independent tests, and products that have since been reformulated, all copied from one another. The ADA adds an important caution most charts omit: RDA values below 250 should not be used to rank products against each other — it's a lab metric, not a wear predictor.
Which RDA numbers are actually verified?
| Product | RDA | Provenance — read this column |
|---|---|---|
| Toothbrush + plain water | ~4 | Chart, unverified |
| Plain baking soda | ~7 | Chart, unverified |
| Elmex Sensitive Plus | ~30 | Chart, unverified |
| Sensodyne ProNamel | 34–37 | Corroborated across multiple sources — the most consistently low mainstream value |
| Arm & Hammer Dental Care (plain) | ~35 | Chart, unverified |
| Clinpro 5000 | 62.15 | VERIFIED — 3M technical profile |
| Opalescence Whitening | ~78 | Manufacturer stated |
| Sensodyne Extra Whitening | ~104 | Chart, unverified |
| PreviDent 5000 Booster | 112.03 | VERIFIED — 3M comparative testing (formula contains mica) |
| PreviDent 5000 Plus | Not published | Cannot be certified under a ≤70 rule — fine where roots are not exposed |
| Whitening / tartar-control category | 100–200 | Various — the harshest shelf |
One nuance the verified pair teaches: on enamel, Clinpro and the Booster are statistically equivalent (REA 3.49 vs 3.39). The difference is dentin — root surface — only. Which brings us to the real question.
When does RDA actually matter?
RDA is near-irrelevant for an intact, low-risk mouth — and becomes the governing variable the moment roots are exposed. That's the whole framework in one sentence. In situ, abrasivity showed no significant effect on sound enamel (erosion did); on dentin, both erosion and abrasion matter. So if your gums haven't receded, agonizing over RDA is wasted worry — spend the attention on acid timing instead (the notches article explains). If roots show, hold a hard line: verified RDA ≤ 70, which in practice means ProNamel or Elmex for sensitivity-dominant mouths, and Clinpro 5000 when you also need prescription-strength fluoride — the only product combining 5,000 ppm with a manufacturer-verified sub-70 RDA. (Clinpro carries titanium dioxide and tricalcium phosphate; once dentin is exposed, abrasivity outranks ingredient purity, and we accept that trade knowingly.)
A trap worth naming from the heavy-metals article: pastes built on calcium carbonate or bentonite clay are frequently high-RDA and carried the heaviest contamination — so a patient self-managing recession with a "gentle natural" paste is often doing the opposite of what they intend. Silica formulations span the whole RDA range, so abrasive type alone doesn't predict the number; provenance of the figure does.
What this means for you
Ignore any chart that doesn't date its figures or name its sources. If your gums are intact: pick by fluoride and preference, skip whitening formulas, and stop worrying. If roots show: ProNamel, Elmex, or — if you're also cavity-prone — ask us to prescribe Clinpro 5000, and drop whitening/tartar-control pastes entirely. The rest of the label story is in the pillar guide.
Frequently asked questions
What is a safe RDA level for toothpaste?
The FDA considers up to 200 acceptable for everyday use, and the ADA cautions against using sub-250 values to rank products — on intact enamel the number barely matters. The place a threshold earns its keep is exposed roots, where we hold to verified RDA ≤ 70 because dentin wears far faster than enamel.
Why do RDA charts disagree so much?
Because most are undated copies of copies, mixing manufacturer data, independent labs using different protocols, and reformulated products under old names. The same product appears at 62 and 125 on different charts. Trust figures traceable to manufacturer technical documentation or corroborated across multiple independent sources; treat the rest as folklore.
Is baking soda toothpaste abrasive?
Plain baking soda itself is famously gentle — around RDA 7 on the charts, though unverified. Finished baking-soda pastes vary with everything else in the formula, so the ingredient's reputation doesn't transfer automatically. Judge the product's number and its provenance, not the headline ingredient.
Which prescription toothpaste is gentlest on exposed roots?
Clinpro 5000 — manufacturer-verified at RDA 62.15, the only 5,000 ppm option with a verified sub-70 figure. PreviDent 5000 Plus has the cleanest ingredient list of the prescription options but an unpublished RDA, so it's our pick when roots are not exposed. Avoid PreviDent Booster (verified 112) on exposed roots.
Educational content, not a substitute for an examination. RDA figures from manufacturer technical documentation where marked verified; others as attributed. Formulations change — verify current labelling.
Not sure if your roots count as "exposed"? That's a ten-second answer in the chair — Keene · Joshua · (817) 476-4537.