Diet and dental erosion.

Dental erosion (erosive tooth wear) is the result of a pathologic, chronic, localized loss of dental hard tissue that is chemically etched away from the tooth surface by acid and/or chelation without bacterial involvement. Acids of intrinsic (gastrointestinal) and extrinsic (dietary and environmental) origin are the main etiologic factors. Tooth wear including dental erosion is not a new phenomenon, but it is receiving increased attention because levels of dental caries have been decreasing in many industrialized societies. The prevalence of dental erosion changes with age and seems to depend on the society a person lives in, which could explain in part the large between-study variations (for a review, see Nunn). The progression (severity?) of erosion seems to be greater in older (52 to 56 y) than in younger (32 to 36 y) adults and has a skewed distribution in which a small proportion of the population has the most severe levels of erosion and the majority has low levels of erosion. In the study by Lussi and Schaffner, the group with high progression (severity?) had the following significant differences compared with the group with small progression: intake of dietary acids (P 0.01), the buffering capacity of stimulated saliva (P 0.02), and the bristle stiffness of the toothbrush (P 0.01). The dietary habits of the high-progression group changed very little between the first and second examinations despite discussions with patients about the dangers of erosive foodstuffs. Overall, the high-progression group had four or more acid intakes per day. An intake frequency of the same magnitude has been associated with an increased risk for erosion in children. It is well known that acidic food and drink can soften dental hard tissues. In 2000, the consumption of soft drinks and fruit juices in England amounted to over 120 L per capita per year, representing on average of about 50% of the total individual fluid consumption (A. Rugg-Gunn, personal communication, 2001). The erosive activity of citric, malic, phosphoric, and other acids has been tested and demonstrated in many in vitro, in situ, and in vivo studies. Epidemiologic studies and numerous case reports have found diet to be an important etiologic factor for the development and progression of erosion. In one study, 391 randomly selected individuals were investigated for dental erosion. Data from interviews and multiple regression analyses associated the consumption of citrus fruits and fruit drinks with the presence of erosion of facial tooth surfaces (surfaces adjacent to the cheek and lip) and occlusal erosion (biting surfaces). Chronic vomiting appeared to be most decisive factor for erosion on tooth surfaces adjacent to the palate. A case-control study of 106 cases of erosion showed the same pattern with citrus fruits, soft or sport drinks, apple vinegar, and vomiting associated with dental erosion. Dietary acids most commonly affect the labial surface of the upper incisors (surfaces adjacent to the lips). This could be due to the slow clearance of acids at this site. Excessive consumption of acidic food and beverages may produce dental hard tissue erosion. However, chemical, biological, and behavioral factors influence the development of dental erosion and are summarized in Table I. When dental erosion is clinically detected or when there is indication for an increased risk, risk assessment should be undertaken. A very important part is the case history. However, chairside interviews are generally not sufficient to determine dietary habits leading to erosion because patients may be unaware of their acid ingestion. Therefore, it is advisable to have such patients monitor their complete dietary intake for 4 consecutive days, including a weekend day, because dietary habits during weekends can differ considerably from those during weekdays. Patients should record, in writing, the time, quality, and quantity of all ingestions including diet supplements such as vitamin C tablets or solutions, iron tonics, and acidic candies (excessive consumption of the latter combined with a low salivary buffering capacity may aggravate existing erosive lesions). The dietary record should be sent to the dentist before the next appointment to enable analysis. In addition to estimating the erosive potential of different foodstuffs and drinks and taking into account the various parameters mentioned above, the dentist should analyze the frequency of ingestion of acidic (and of sugar-containing) foodstuffs with main meals and in-between snacks and estimate the duration of the acid challenge. In summary, it is important to know how, how often, how much, and when a particular drink or foodstuff is ingested. If