Several rechargeable power toothbrush models offer pressure sensors to monitor the force being applied by the user when brushing. Pressure sensors alter the brush movement to make patients aware when too much pressure is being applied. Many power toothbrushes hare equipped with a light which illuminates when too much pressure is applied (Figure 11). Other models may also include a light in the handle of the toothbrush that is activated upon excess pressure.
Brush filaments are made of soft end-rounded nylon in various diameters. Endrounding occurs during the manufacturing process after the bristles are inserted into the brush head. The bristles are sanded and then polished to a smooth rounded tip. A bristle’s stiffness is directly related to its diameter and length: thicker bristles require more force to bend than thinner bristles. Soft bristles are preferred, because hard bristles may abrade the gingiva. Now, most manufacturers (but not all) use endrounding technology to ensure safety for both hard and soft tissues in the oral cavity. Oral-B has a high quality standard, with brush bristles having greater than or equal to 90% endrounding.