The main dietary influences on teeth are, with the exception of ingested fluoride, local rather than systemic. The frequent use of carbohydrates which can be rapidly fermented by dental plaque micro-organisms is the major factor in dental decay. Sweetened and/or highly acidic soft drinks or medicines sweetened with sugars may damage the teeth. Similarly infant's comforters also have their dangers if they provide prolonged exposure of the teeth to cariogenic conditions. Although dental caries is primarily a disease of children many adults still develop new lesions and adults who have lost gingival tissue through periodontal disease may develop root surface caries. Pathological conditions of the oral mucosa can arise from nutritional disorders or inappropriate dietary habits. Health education is most effective when it carries a positive message so encouraging patients to eat the right kind of tasty snacks and to round off meals with sugar-free products or a modicum of cheese should in healthier eating without conflicting with general health guidelines.