The Sensodyne 3.5 Toothbrush is a very compact brush with a small head and medium bristle and has been especially designed for people who have sensitive teeth. Brush filament ends are round and gentle to help prevent gum damage Slim neck design to make reaching the back of the mouth easier Easy grip handle The Sensodyne Search 3.5 has been one of the professions most popular toothbrushes for many years and comes very recommended by Dentists. Dentists recommend that you change your toothbrush at least every 3 months.