| 摘要 |
<p>The head of the toothbrush (1) is of cylindrical form with the bristles (21, 22, 23) attached to the concave surface (11). Teh bristles are arranged in three rows and aligned radially w.r.t. the cylindrical surface. This arrangement of the bristles ensures that all the surfaces of the tooth (4) are cleaned as well as any hollows (5) in the gum (6). In addition the bristles penetrate the interstices between the teeth so that all particles of food are removed and so reduce the risk of dental decay. The toothbrush is made in three different sizes to suit children up to six years old, children between six and twelve, and adults.</p> |
