Background—Cleaning Efficiency Index (CEI)
In dentifrices, good stain removal properties combined with low dentin abrasivity is extremely important. The goal in dentifrices development is to optimize stain removal without causing harmful abrasion to the teeth.
The Cleaning Efficiency Index (CEI) was introduced by Schemehorn et al.1 in 1992. It is calculated according to the equation:
CEI = (RDA + PCR - 50) ÷ RDA
RDA—Relative Dentin Abrasion (a standardized scale developed by the American Dental Association [ADA] to quantify the abrasivity of dentifrices)
PCR—Pellicle Cleaning Ratio (ability of dentifrices to remove stains)
High Cleaning Efficiency Index indicates high stain removal ability (high PCR) combined with low abrasivity (low RDA).
PCR and RDA tests were conducted on the izzo Polishing Cup/Polishing Paste system by Therametric Technologies, Inc., in Noblesville, IN. Specific details of the PCR test are described in the test protocols and test results.2
The results indicated that the CEI of the izzo Polishing Cup/Polishing Paste system is 2.46.
According to Putt et al. study conducted by Indiana University-Purdue University,3 the figure below compiles RDA values from various commercial dentifrices that are marketed for cleaning, whitening, and/or polishing capabilities. CEI data plotted in this chart is obtained by testing conducted by Therametric Technologies, Inc., in Noblesville, IN;3 it is the same laboratory that was used by Premier Dental to evaluate the RDA of the izzo system.
The PCR, RDA, and CEI values of 26 advanced cleaning/whitening toothpastes from leading brands are summarized in the table above.3 Thus, with a CEI of 2.46, the izzo Polishing Cup/Polishing Paste system is 93% higher in cleaning efficiency than the average of 26 advanced cleaning/whitening toothpastes from leading brands.
- The izzo Polishing Cup/Polishing Paste system exhibits a unique combination of high stain removal ability (high PCR) combined with low abrasivity (low RDA). Thus, it demonstrates an outstanding CEI.
- The izzo Polishing Cup/Polishing Paste has a 93% higher cleaning efficiency than the average of 26 of the most common commercial dentifrices systems with whitening claims tested in Indiana University-Purdue University study.
1B.R. Schemehorn, T.L. Ball, G.M. Henry, and G.K. Stookey, Comparing Dentifrice Abrasive Systems with Regard to Abrasion and Cleaning. J Dent Res 1992; 71:559.
2izzo 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.
3M.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.