This document discusses different types of toothbrushes, including classifications based on length, bristle diameter, and head and bristle designs. It also covers modifications to toothbrush handles and heads over time. Sonic and ionic toothbrushes are described as using high frequency vibrations or charged ions, respectively, to aid in plaque and bacteria removal. The document recommends replacing toothbrushes every 3 months and discusses various methods for disinfecting toothbrushes, including chemical treatments and UV light sanitization. Finally, it reviews several studies that have compared the plaque removal effectiveness of worn versus new toothbrushes and high versus low brushing forces.