In general, the bristles of a regular toothbrush are too soft to mechanically remove the layer of dirt and bacteria from the tongue surface. Toothbrushes are designed to clean the smooth surfaces of enamel instead of the soft tissue of the tongue. It is also more likely that a toothbrush will cause your natural mouth reflex. Using a special tongue cleaner is usually a better option because it is ergonomically designed to remove the maximum amount of film without causing discomfort.