The Pro-phy-lac-tic toothbrush
One of the first factories to produce American-made toothbrushes was the Florence Manufacturing Company established in Massachusetts in 1866 as a maker of various household brushes. In 1888 they began selling what became the popular Pro-phy-lac-tic toothbrush based on a patented design and trademark acquired from New York dentist Dr. Meyer L. Rhein. The toothbrush featured three rows of serrated bristles with longer end tufts. Distinctive traits included a concave head tapered toward the end and a handle embossed with a distinct number or symbol to help family members distinguish their individual brushes. A hole at the handle end, for hanging the brush to dry the highly water-absorbent, hollow bristles, discouraged bacterial growth and made the brush more hygienic. As the enduring toothbrush of choice, yearly average sales, encouraged by an annual advertising outlay around $500,000, reached 7.5 million from 1924 to 1933, and the brush remained in demand until the mid-1970s.