Oral hygiene is the field of dentistry concerned with the removal of plaque, tartar and stains, root planing, tooth polishing and whitening, the application of fissure sealants, desensitisation, the application and removal of periodontal dressings, and oral health education. It involves the diagnosis, prevention and treatment of oral diseases and has a vital role to play in the success of treatment carried out in other fields of dentistry. The educational aspect is extremely important, involving the teaching and demonstration of specific techniques contributing to the improvement of oral health. Good oral hygiene is a determining factor in the prevention of most diseases affecting oral health, and involves the removal of particles of food and preventing certain types of bacteria attaching to the teeth and gums which, if not removed, will lead to the formation of plaque and tartar, the main causes of tooth decay and periodontal disease. A proper programme of prevention and care involves regular visits to the oral hygienist (at least every six months) and daily care procedures recommended by the dentist or hygienist should be followed. This includes proper brushing (at least twice a day), the use of dental floss (at least once a day, preferably before going to bed) and the use of elixirs or mouthwashes. If symptoms such as bleeding or sore gums during brushing, bad breath or constant sensitivity appear, make an appointment with your dentist or hygienist.