Abrasion-Cleaning Unit experimental models
RDA (Radioactive Dentin Abrasivity)
This method is used to determine the abrasive level of dentifrices and abrasives in human root dentin. The RDA value is calculated in relation to the abrasive level of a standard abrasive material, which is given the empirical value of 100. It involves the laboratorial procedure developed by Hefferren (1976) and recommended by the ADA and ISO 11609.
REA (Radioactive Enamel Abrasivity)
This method is used to determine the abrasive level of dentifrices and abrasives in human enamel. The REA value is calculated in relation to the abrasive level of a standard abrasive material, which is given the empirical value of 10. It is based on the laboratorial procedure developed by Hefferren (1976) and recommended by the ADA and ISO 11609.
PCR (Pellicle Cleaning Ratio)
This test was developed in order to assess the ability of dentifrices to remove stained pellicle artificially created on enamel surfaces; that is, to determine the cleaning ability of dentifrice formulations. Previous studies (J. Dent. Res., 61:1236, 1982) have indicated that the results of this test with dentifrice slurries compare favorably with those obtained in controlled clinical trials. The PCR value is calculated relatively to a standard material which is given the empirical value of 100.
EPP (Enamel Polishing Potential)
This method is based on the work previously published by Bailey and Phillips (1950), on the study of abrasive prophylactic agents and techniques on enamel surfaces. Toothbrushing provides several benefits, including the polishing of enamel surfaces. Different toothpastes/abrasives may provide different polishing potential for enamel surfaces, and this can be determined by light reflection analysis. The outcome for this test is the difference in enamel gloss (or light reflection) between the pre- and post-treatment measurements.
