When it comes to choosing a toothpaste, most people focus on flavor, whitening claims, or price. But there is one number that matters far more to the long-term health of your teeth: the RDA value.

If you are searching for the gentlest toothpaste or a truly low abrasion toothpaste, understanding RDA is one of the smartest places to start. It helps explain why some formulas leave teeth feeling polished without putting your enamel through unnecessary wear.

What Is RDA?

Relative Dentin Abrasion (RDA) is the scientific standard used to measure how abrasive a toothpaste is against your tooth's dentin — the layer just beneath your enamel. The test follows the ADA-recommended procedure detailed in ISO 11609 and ANSI/ADA Standard No. 130, using irradiated human dentin specimens and a standardized cross-brushing machine.

The scale works like this:

• 0–70: Low abrasion (safest for daily use)
• 70–100: Medium abrasion
• 100–150: High abrasion
• 150–250: Extremely abrasive (FDA upper limit is 200, ADA allows up to 250)

The lower the number, the gentler the toothpaste is on your teeth. Simple as that.

Our Lab Results: RDA 35

We sent our Living Crystal Toothpaste to Therametric Technologies in Noblesville, Indiana — an independent dental product testing laboratory — for official RDA testing under Study Number 25-454.

The results? Our Living Crystal Toothpaste scored a mean RDA of 35.51 ± 0.50 across 8 dentin specimens. That puts it firmly in the ultra-low abrasion category — gentle enough for even the most sensitive teeth, while still effectively cleaning.

The study was conducted in full compliance with FDA GLP Guidelines, using the exact procedure recommended by the ADA. This is not marketing — it is science.

How Does Living Crystal Compare?

Here is where it gets interesting. Look at how popular toothpaste brands stack up:

Living Crystal Toothpaste is nearly half the abrasion of Colgate Regular and less than a third of Crest Regular. Even toothpastes marketed as "sensitive" like Crest Sensitivity Protection score three times higher.

Why Does This Matter?

Every time you brush, abrasive particles in your toothpaste scrub against your enamel and dentin. Over months and years, highly abrasive toothpastes can:

• Wear down enamel — your teeth's protective outer layer does not grow back
• Expose dentin — leading to increased sensitivity and yellowing
• Damage gum tissue — especially at the gum line where recession occurs
• Create micro-scratches — which can actually trap stains rather than remove them

An ultra-low RDA toothpaste like Living Crystal cleans effectively while preserving your enamel for life.

What Makes Living Crystal Different

Living Crystal Toothpaste achieves this remarkable gentleness because of what it does not contain. No harsh silica abrasives, no sodium lauryl sulfate (SLS), and no synthetic whitening agents that trade short-term brightness for long-term enamel damage.

Instead, our formula relies on micro-hydroxyapatite — the same mineral your teeth are naturally made of — to remineralize and strengthen enamel from the inside out. Combined with organic botanicals grown on our own natural regenerative farm in Vero Beach, Florida, it is toothpaste that works with your teeth, not against them.

If you want a deeper explanation of why shoppers are searching for low RDA options, read our guide to low abrasion toothpaste and what RDA means for enamel.

The Bottom Line

An independent, FDA GLP-compliant laboratory confirmed what we have always known: Living Crystal Toothpaste is one of the gentlest, most enamel-safe toothpastes available anywhere. At an RDA of 35, it is in a class of its own — delivering real cleaning power without the abrasive damage hiding in most mainstream toothpastes.

Your enamel is irreplaceable. Choose a toothpaste that respects that.

Study conducted by Therametric Technologies, Inc. (Study No. 25-454) following ISO 11609 and ANSI/ADA Standard No. 130 protocols, in compliance with FDA GLP Guidelines. Full report available upon request.