Comparison of changes in salivary pH levels after consumption of plain milk and milk mixed with sugar

Studies of dietary effects on saliva were common in the early part of this century, but it is now understood that such studies are of little value because the effects of other physiologic variables, such as time of day, were seldom controlled in the experimental design. The main salivary factors that, from theoretical considerations, might be expected to influence the process of caries are flow rate and the concentrations of calcium, phosphate, bicarbonate, hydrogen ions, fluoride, urea, and protein (particularly amylase). As the mankind has evolved, a drastic change has been seen in the dietary fermentable carbohydrate which eventually is associated with increased prevalence of dental caries. Milk is consumed with sugar syrups or honey to add flavor which eventually increases sugar content of milk, putting the children at a higher risk of dental caries. This study was conducted to evaluate and compare the acidogenic potential of milk as compared to milk and sugar at various time intervals. A total of 230 children aged 12 to 15 years were examined, 60 children which equal number of males and females (30 each) who satisfied the inclusion criteria were randomly selected and assigned to two groups, Group I: Plain milk (250 mL) and Group II: Milk and sugar (250 mL + 1 table spoon sugar =12.50 gm). After recording the resting pH, the change in the salivary pH in the respective groups after consuming the test meal was recorded after 5 minutes, 10 minutes, after 15 minutes, after 30 minutes and 120 minutes. The results show that there was no statistical significant difference in pH between the two groups. Statistically significant difference was seen at 10, 15, 30 minutes with highest at 15 minutes (p = 0.001) between plain milk (group I), milk and sugar (group II). The milk group showed a significant decrease in pH at 10 minutes. However, pH returned to normal at 15 - 30 minutes in group II. The study concluded that milk when added with sugar as did not pose a risk of demineralization as there was no decrease of pH below the limit of critical pH of 4.5 to 5.5.