The earliest toothbrushes were simply small sticks mashed and frayed at one end to increase their cleaning surface. Ancient Roman patricians employed special slaves to clean their teeth, and toothbrushing formed part of some ancient religious rituals. The bristle brush was probably invented by the Chinese; it came to Europe during the seventeenth century and soon was widely used. French dentists, who were the most advanced in Europe at the time, advocated the use of toothbrushes in the seventeenth and early eighteenth centuries. In pre-Revolutionary America, dentists urged the use of bristle toothbrushes. Nylon has replaced natural bristles in modern brushes. Hard bristles, once recommended, are now thought to be too abrasive, and soft nylon bristles with rounded ends are preferred. Special brushes have also been designed to remove plaque and debris from relatively large spaces between teeth, or spaces between caps and bridges...