A STRUCTURELESS RECURRENT DEPOSIT ON TEETH

¹ Department of Dental Research, Chemical Division, The Procter and Gamble Company, Ivorydale, Ohio

A brown pellicle has been found to form regularly on the teeth of some but not all of the persons who do not use dentifrice abrasives in their oral hygiene. The deposit can be readily removed by 1 or 2 brushings with dentifrice abrasives, and it will recur whenever abrasive brushings are omitted for 1 or 2 weeks. A method devised for examining anterior teeth with a binocular microscope showed that the brown pellicle accumulated gradually and in a regular manner, and that repeated accumulations did not seem to affect the tooth surfaces in any way.

Under high magnification the deposit was seen to consist of a structureless, bacteria-free, faintly Gram-positive pellicle with which were frequently associated traces of a granular, Gram-negative substance. The pellicle gave positive protein tests and seemed to be chiefly organic material. It was insoluble in all of the chemical reagents tested at room temperature, and dissolved at 90°C. only in strong hydrolytic solutions, which suggested that it should be classed as a keratin. Some similarities between brown pellicle and known deposits were discussed.