Safe and Gentle: a Measure of izzo Abrasivity

Background—Relative Dentin Abrasivity (RDA)

The Relative Dentin Abrasion (RDA) is a standardized scale developed by the American Dental Association (ADA) to quantify the abrasivity of dentifrices.1, 2 It assigns dentifrices an abrasivity value relative to a standard reference abrasive that is arbitrarily given an RDA value of 100.1,3 All dentifrices at or below 2.5 times the reference value, or 250 RDA, are considered safe and effective.4 Clinical evidence suggests lifelong use of a proper brushing technique with a toothbrush and toothpaste at an RDA of 250 or less produces limited wear to dentin and virtually no wear to enamel.5

The RDA testing method and the upper limit of 250 has been adopted by the American National Standards Institute/American Dental Association (ANSI/ADA) and is included in the manufacturing standards outlined in ANSI/ADA Standard No. 130:2020 on toothpastes. 6

All dentifrices with the ADA Seal of Acceptance must have an RDA of 250 or less. The maximum value for FDA approval is 200.

Here is how to interpret the RDA values:

  • From 0 to 70 = low abrasion
  • 70 to 100 = midrange abrasion
  • 100 to 150 = highly abrasive
  • 150 to 250 = considered unsafe for teeth7

Quantifying izzo’s Polishing Cup/Polishing Paste System’s Relative Dentin Abrasivity (RDA)

Method Description
The RDA test on the izzo Polishing Cup/Polishing Paste system was conducted by Therametric Technologies, Inc., in Noblesville, IN. Specific details of the RDA test are described in the test protocol (attached).

RDA test results on the izzo Polishing Cup/Polishing Paste system are summarized in the Relative Dentin Abrasion (RDA) Testing, Prophy Pastes, and Powered Prophy Brushes Study, Number 21-223, Final Report.8

The results indicate that the izzo Polishing Paste (izzo Prototype Formulation [Coarse] used in the final product) when used with the izzo Polishing Cup has an RDA of 72.16, ± 8.14, which is at the low end of the midrange abrasion values. Therefore, the izzo Polishing Cup/Polishing Paste systemis gentle and safe for use on teeth.

According to the Putt et al. study conducted by Indiana University-Purdue University,9 the figure below compiles RDA values from various commercial dentifrices that are marketed for cleaning, whitening, and/or polishing capabilities. RDA data plotted in this chart is obtained by testing conducted by Therametric Technologies, Inc., in Noblesville, IN;9 it is the same laboratory that was used by Premier Dental to evaluate the RDA of the izzo system.

In addition, the average RDA of 26 advanced cleaning/whitening toothpastes from leading brands is 133. Thus, with an RDA of 72.16, the izzo Polishing Cup/Polishing Paste system is 46% less abrasive than the average of 26 advanced cleaning/whitening toothpastes from leading brands.


  • According to the ADA, dentifrices with an RDA below 150 are considered safe.
  • The RDA value of the izzo Polishing Cup/Polishing Paste is 72.16, which is at the border of the low range and midrange abrasion values; therefore, the izzo Polishing Cup/Polishing Paste is not only safe but gentle on the teeth.
  • In addition, the RDA value of the izzo Polishing Cup/Polishing Paste is 46% lower than the average of 26 of the most common commercial dentifrices systems with whitening claims tested in an Indiana University-Purdue University study.


1ADA Guidance:

2Abrasivity of current dentifrices. Council on Dental Therapeutics. J Am Dent Assoc 1970; 81(5):1177-8.

3C. Gonzalez-Cabezas, A.T. Hara, J. Hefferren, and F. Lippert, “Abrasivity Testing of Dentifrices—Challenges and Current State of the Art,” Monogr Oral Sci [RG2] 2013; 23:100-7.

4S. St. John, D.J. White, “History of the Development of Abrasivity Limits for Dentifrices,” J Clin Dent 2015; 26(2):50-4.

5M.L. Hunter, M. Addy, M.J. Pickles, and A. Joiner, “The Role of Toothpastes and Toothbrushes in the Aetiology of Tooth Wear,” Int Dent J 2002;52:399-405.
6American National Standards Institute ADA. ANSI/ADA Standard No. 130 for Dentifrices. American National Standards Institute, American Dental Association. Chicago: American Dental Association. 2020.

7P. Maragliano-Muniz, “Protected by a Safe RDA: Setting the Record Straight about Toothpaste Abrasivity,” RDH Magazine, Dec. 13, 2016;

8.izzo Testing Results: PCR and RDA test Results. Therametric Technologies, Inc., Noblesville, IN. Pellicle Cleaning Ratio: Study Number 21-266, July 2021; Relative Dentin Abrasion: Study Number 21-223, May 2021.

9M.S. Putt, B.R. Schemehorn, and M.H. Moore, “Abrasion, Polishing, and Stain Removal Characteristics of Various Commercial Dentifrices In Vitro,” The Journal of Clinical Dentistry, 2011; 22(1):11-8.