Figure 1
From: In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva
Tooth staining apparatus. The apparatus consists of an aluminum platform base, which supports a Teflon rod (3/4 inch in diameter) connected to an electric motor, which by means of a speed reduction box, rotates the rod at a constant rate of 1.5 rpm. Threaded screw holes are spaced at regular intervals along the length of the rod. The enamel specimens are attached to the rod by first gluing the head of a plastic screw to the back of the specimen, then screwing the enamel sample onto the rod. Beneath the rod is a removable, 300 ml capacity trough which held the tooth staining broth.