Tooth-brush with shaped bristles - has bristles converging towards centre with central row taller than outer

摘要

The toothbrush has outer rows of bristles (1,5) that converge towards the central row (3). Their height diminishes towards the outside to give a symmetrical pentagonal shape. The head of the brush is in the shape of an isosceles triangle that is truncated at the top. The central row of bristles is at an angle of 90 degrees to the head and the neighbouring rows (2,4) are at 80 degrees and the outer rows are at 75 degrees. The angle between the working surface of the bristles and the horizontal is between 10-45 degrees, and is preferably 25 degrees.