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:

RDADentifrice brand and varietySource
07 straight baking sodaChurch & Dwight
08 Arm & Hammer Tooth PowderChurch & Dwight
30 Elmex Sensitive PlusElmex
35 Arm & Hammer Dental CareChurch & Dwight
42 Arm & Hammer Advance White Baking Soda PeroxideChurch & Dwight
44 Squigle Enamel SaverSquigle
48 Arm & Hammer Dental Care SensitiveChurch & Dwight
49 Arm & Hammer Peroxicare Tartar ControlChurch & Dwight
49 Tom's of Maine Sensitive (given as 40's)Tom's
52 Arm & Hammer Peroxicare RegularChurch & Dwight
53 Rembrandt Original (RDA)Rembrandt
54 Arm & Hammer Dental Care PM Bold MintChurch & Dwight
57 Tom's of Maine Children's, Wintermint (given as mid-50's)Tom's
62 SupersmileSupersmile
63 Rembrandt Mint ('Heffernan RDA')Rembrandt
68 Colgate RegularColgate-Palmolive
70 Colgate TotalColgate-Palmolive
70 Arm & Hammer Advance White SensitiveChurch & Dwight
70 Colgate 2-in-1 Fresh Mint (given as 50-70)Colgate-Palmolive
79 SensodyneColgate-Palmolive
80 AIMUnilever
80 Close-UpUnilever
83 Colgate Sensitive Maximum StrengthColgate-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 PlusRembrandt
94 Plus WhiteIndiana study
95 Crest Regular (possibly 99)P&G (P&G)
101 Natural WhiteIndiana study
103 MentadentSquigle
103 Arm & Hammer SensationChurch & Dwight
104 Sensodyne Extra WhiteningColgate-Palmolive
106 Colgate PlatinumIndiana study
106 Arm & Hammer Advance White PasteChurch & Dwight
107 Crest Sensitivity ProtectionColgate-Palmolive
110 Colgate HerbalColgate-Palmolive
110 Amway Glister (given as upper bound)Patent US06174515
113 Aquafresh WhiteningIndiana study
117 Arm & Hammer Advance White GelChurch & Dwight
117 Arm & Hammer Sensation Tartar ControlChurch & Dwight
120 Close-Up with Baking Soda (canadian)Unilever
124 Colgate WhiteningIndiana study
130 Crest Extra WhiteningIndiana study
133 Ultra brite (or 120-140)Indiana study (or Colgate-Palmolive)
144 Crest MultiCare WhiteningP&G
145 Ultra brite Advanced Whitening FormulaP&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 MintChurch & Dwight
200 Colgate 2-in-1 Tartar Control/Whitening or Icy Blast/Whitening (given as 190-200)Colgate-Palmolive
200 recommended limitFDA
250 recommended limitADA

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.