The dental hygienist is a key figure in the prevention of periodontal disease and in the maintenance of health in treated patients. The hygienist’s duty is to teach effective brushing technique to remove plaque. All patients accept the act of brushing as a natural part of their daily routine. Calculus, whether supramarginal or submarginal, is the supreme plaque holder. If calculus is not removed, the success of any brushing instruction is prejudiced. Scaling is the removal of adherent calcified deposit (calculus) from the surfaces of the teeth. The root surfaces may be covered by fine spots or rings of hard calculus, some of which may be so firmly attached that finger of calculus project into defects in the cementum. During root planing, a certain amount of gingival curettage takes place as an incidental—this is the removal of diseased epithelial lining of the inside wall of the crevice or pocket. The use of anesthetics is also emphasized to control pain sensations during oral prophylaxis. The responsibilities of the dental hygienist in patient education are also described in this chapter.