DES 1840 - Preventive Dentistry and Nutrition DES 1840 - Preventive Dentistry and Nutrition Topics include hard and soft deposits, stains, oral hygiene instructions, plaque indices, fluorides, sealants, tooth brushing techniques, flossing, dentifrices, mouth washes, oral hygiene aids, and the oral hygiene needs of special care patients. Nutrition as it relates to dental care is also included in this course. Emphasis is placed on personal and patient oral hygiene skills development. Occupational (A.S. and A.A.S.)