Toothpaste RDA Values
After a few months of brushing with Sonicare powered toothbrush, the front of my teeth started feeling smooth. I could tell that something mechanical must be going on, but not exactly what. Was Sonicare chowing through my enamel? Probably. What do I do about it? Use a gentle toothpaste. Which toothpastes are gentle? I don't know.
Toothpaste makers regularly measure their product's abrasivity. It's necessary for FDA approval, and usually is not included in marketing. Abrasivity measurements are given by what's known as an RDA value which stands for radioactive dentin abrasion or relative dentin abrasivity.
To measure RDA in the lab, the tester starts with extracted human or cow teeth. The teeth are irradiated in a neutron flux, mounted in methylmethacrylate (bone glue), stripped of enamel, inserted into a brushing-machine, brushed by ADA standards (reference toothbrush, 150g pressure, 1500 strokes, 4-to-1 water-toothpaste slurry). The radioactivity of the rinsewater is then measured and recorded. For experimental control, the test is repeated with an ADA reference toothpaste made of calcium pryophosphate, with this measurement given a value of 100 to calibrate the relative scale.
These are RDA values for common toothpastes:
| RDA | Dentifrice brand and variety | Source |
|---|---|---|
| 07 | straight baking soda | Church & Dwight |
| 08 | Arm & Hammer Tooth Powder | Church & Dwight |
| 30 | Elmex Sensitive Plus | Elmex |
| 35 | Arm & Hammer Dental Care | Church & Dwight |
| 42 | Arm & Hammer Advance White Baking Soda Peroxide | Church & Dwight |
| 44 | Squigle Enamel Saver | Squigle |
| 48 | Arm & Hammer Dental Care Sensitive | Church & Dwight |
| 49 | Arm & Hammer Peroxicare Tartar Control | Church & Dwight |
| 49 | Tom's of Maine Sensitive (given as 40's) | Tom's |
| 52 | Arm & Hammer Peroxicare Regular | Church & Dwight |
| 53 | Rembrandt Original (RDA) | Rembrandt |
| 54 | Arm & Hammer Dental Care PM Bold Mint | Church & Dwight |
| 57 | Tom's of Maine Children's, Wintermint (given as mid-50's) | Tom's |
| 62 | Supersmile | Supersmile |
| 63 | Rembrandt Mint ('Heffernan RDA') | Rembrandt |
| 68 | Colgate Regular | Colgate-Palmolive |
| 70 | Colgate Total | Colgate-Palmolive |
| 70 | Arm & Hammer Advance White Sensitive | Church & Dwight |
| 70 | Colgate 2-in-1 Fresh Mint (given as 50-70) | Colgate-Palmolive |
| 79 | Sensodyne | Colgate-Palmolive |
| 80 | AIM | Unilever |
| 80 | Close-Up | Unilever |
| 83 | Colgate Sensitive Maximum Strength | Colgate-Palmolive |
| 91 | Aquafresh Sensitive | Colgate-Palmolive |
| 93 | Tom's of Maine Regular (given as high 80's low 90's) | Squigle (Tom's) |
| 94 | Rembrandt Plus | Rembrandt |
| 94 | Plus White | Indiana study |
| 95 | Crest Regular (possibly 99) | P&G (P&G) |
| 101 | Natural White | Indiana study |
| 103 | Mentadent | Squigle |
| 103 | Arm & Hammer Sensation | Church & Dwight |
| 104 | Sensodyne Extra Whitening | Colgate-Palmolive |
| 106 | Colgate Platinum | Indiana study |
| 106 | Arm & Hammer Advance White Paste | Church & Dwight |
| 107 | Crest Sensitivity Protection | Colgate-Palmolive |
| 110 | Colgate Herbal | Colgate-Palmolive |
| 110 | Amway Glister (given as upper bound) | Patent US06174515 |
| 113 | Aquafresh Whitening | Indiana study |
| 117 | Arm & Hammer Advance White Gel | Church & Dwight |
| 117 | Arm & Hammer Sensation Tartar Control | Church & Dwight |
| 120 | Close-Up with Baking Soda (canadian) | Unilever |
| 124 | Colgate Whitening | Indiana study |
| 130 | Crest Extra Whitening | Indiana study |
| 133 | Ultra brite (or 120-140) | Indiana study (or Colgate-Palmolive) |
| 144 | Crest MultiCare Whitening | P&G |
| 145 | Ultra brite Advanced Whitening Formula | P&G |
| 145 | Colgate Baking Sode & Peroxide Whitening (given as 135-145) | Colgate-Palmolive |
| 150 | Pepsodent (given as upper bound) | Unilever |
| 165 | Colgate Tartar Control (given as 155-165) | Colgate-Palmolive |
| 168 | Arm & Hammer Dental Care PM Fresh Mint | Church & Dwight |
| 200 | Colgate 2-in-1 Tartar Control/Whitening or Icy Blast/Whitening (given as 190-200) | Colgate-Palmolive |
| 200 | recommended limit | FDA |
| 250 | recommended limit | ADA |
Consumer Reports reviewed toothpastes (August 1998). Unfortunately, they did not consider RDA, only stain removal. So, high-abrasivity toothpastes like Ultra brite got the best ratings. I think you should be skeptical of their rankings.
Which toothpaste is the best? Almost every dentist I know swears by Colgate Total, because it has a long-lasting antimicrobial ingredient.