FLOW-RATE AND COMPOSITION OF WHOLE SALIVA IN CHILDREN FROM RURAL AND URBAN THAILAND WITH DIFFERENT CARIES PREVALENCE AND DIETARY-INTAKE

The aim of this study was to compare the prevalence of dental caries, dietary composition and whole salivary flow rates together with some o f the components of saliva between two groups of children aged 12-16 y ears, one group from an urban area and the other from a rural area of Thailand. A stratified random samples were taken by class from one sch ools in each area. The children who had mixed dentition and/or who had migrated from other area of Bangkok and 138 students were selected fr om a school in a rural area of Khon Kaen in northeast Thailand. Result s of completed 24-hour dietary recalls for three consecutive days exam ining the average nutrient intake were compared looking for difference s, if any, between these two groups of children. Dental examinations a nd whole salivary sampling were also undertaken and possible relations hips between some nutrients and certain salivary factors were explored . The prevalence of dental caries was found to be higher in the studen ts living in the urban area. The children in the rural area consumed a higher load of carbohydrate, which came mainly from sticky rice. Ther e was no difference in the protein consumption between the two groups, although the children in the rural area consumed more protein from ve getable sources. The salivary flow rate and the concentrations of fluo ride, calcium and phosphate were significantly higher (p <0.05) in the group from the rural area, while the salivary pH, buffer capacity, co ncentrations of total protein and urea were higher in the urban area. There was no correlation between nutrient intake and salivary composit ion in the children from these two areas, which may suggest that dieta ry nutrients may not have a direct effect on salivary compositions, bu t it was noted that salivary flow rate correlated with salivary urea, albumin and buffer capacity in both areas.