On dental erosion and associated factors.

The aim of this thesis was to explore aspects of dental erosion by investigating its prevalence among young Saudi men and young children, develop a system for its assessment and to evaluate various tentative background factors that may be associated with its occurrence. Saudi military inductees (n = 95) were subjected to questionnaire and clinical examination, including recordings of severity of dental erosion and a number of other oral health parameters. The system applied for grading the severity of dental erosion showed an intraexaminer agreement of 78%. Around one-fourth of the maxillary anterior tooth surfaces exhibited pronounced dental erosion and the average soft drink consumption was 247 liters/year. High level of soft drink consumption and long retention time of the drink in the mouth before swallowing, intensified oral hygiene, mouth breathing and low gingival bleeding index were found to have significant correlations with the presence of dental erosion. Furthermore, less plaque on maxillary palatal tooth surfaces, increased numbers of buccal cervical defects, first permanent molar "cuppings", missing teeth, and lower salivary urea content had significant correlations with the severity of dental erosion. High intake of acidic drinks and fruits, upper respiratory tract problems and frequent taking of medication were common findings in young Saudi children (n = 16) with severe dental erosion. The clinical diagnosis of erosion in deciduous teeth was confirmed by SEM. Enamel from various healthy teeth were subjected to microhardness measurements before and after in vitro exposure to citric acid. Deciduous enamel was found to be softer and relatively more prone to erosion than permanent enamel but the potential for erosion was about the same regardless of the origin of the teeth. Six methods of drinking a sugar-free cola-type drink were assessed in two groups of healthy volunteers. Intraoral pH was measured at specific locations and at predetermined time points using the microtouch method (n = 12), and continuously by using telemetric measurement (n = 6). Of the six methods tested, those in which the drink was in contact with the tooth surface for a prolonged period of time were found to strongly affect intraoral pH. It may be concluded from this thesis that dental erosion is common among young Saudi men and that erosion is associated with many etiological, aggravating and modifying factors. Consumption of soft drinks, amount of palatal plaque on maxillary anterior teeth and salivary urea concentration are some factors related to erosion. The presence of dental erosion in children is likely to be associated with a number of general health and dietary factors but is also aggravated by the relatively more rapid progression of erosion in the deciduous teeth. Drinking method seems to be an important factor in the risk of developing dental erosion.