Radioactive dentin abrasion

Overview
A procedure for the measurement of either tooth enamel or dentin abrasion by the use of human teeth made radioactive by mild neutron irradiation.

Abrasive is the term for a dentifrice cleaning agent which, in concert with the brushing action of the toothbrush, cleans teeth by dislodging food particles and plaque. Several abrasives or cleaning agents are currently marketed in various toothpastes, including dicalcium phosphate, hydrated silica and sodium bicarbonate or baking soda.

Radioactive dentin abrasion method of measurement of dentifrice abrassivenes toward  human teeth was described in 1958 by researchers R. J. GRABENSTETTER, R. W. BROGE, F. L. JACKSON, AND A. W. RADIKE in their article THE MEASUREMENT OF THE ABRASION OF HUMAN TEETH BY DENTIFRICE ABRASIVES: A TEST UTILIZING RADIOACTIVE TEETH.

The procedure is more precise and faster than former methods dependent upon the measurement of the depth of a groove cut into tooth structure. (The former methods was first studied by W. D. Miller in 1907). The results are obtained directly in terms of the amount of human tooth structure worn away by a toothbrush and dentifrice abrasive slurry operating at a known, constant brush pressure and a constant stroke speed. The coefficient of variation of the test is 6-7 when 8 replications are carried out, and 10-15 when only duplicates are run as in the usual routine testing. This is one half to one fourth of the variation involved in the depth-of-cut method and results can be obtained with an expenditure of one half to one third of the time of the former method.

The procedure was later adopted by ADA for measuring of Relative Dentin Abrasion Index,

Radioactive Dentin Abrasion