Course of changes in salivary pH-values after intake of different beverages in young children

The aim of the study was to determine possible differences in decrease of pH-values of whole saliva, following the intake of different beverages.

Twelve boys and 13 girls (4.9 +/- 0.9 years old) participated in this study. A dental examination was performed (dmft). Orange juice (pH = 3.67), instant fennel tea (pH = 7.38), whole milk (pH = 6.84) and mineral water (pH = 5.88) were tested. All beverages were given at the same time of day. Salivary pH and buffering capacities of the beverages were determined with a portable pH-meter. Immediately after intake of a beverage, and 5, 10, 15 and 25 minutes later, whole saliva was collected, and the pH-value was measured again. The statistical evaluation was performed using the Wilcoxon test for paired samples.

Fifteen children had healthy dentitions. Ten subjects had a mean dmft of 1.1 +/- 2.3. The mean base salivary pH was 7.09 +/- 0.07, without differences between the children with and without dental decay. Mineral water led over the whole period of measurements to a significant rise in salivary pH (P < 0.05). Orange juice caused a significant reduction in the salivary pH during the first 10 minutes. After intake of instant tea or milk, significant reductions were found in the period of 5 to 10 minutes. After the intake of instant tea, the reduction was still significant after 15 minutes. During the period of 5 to 10 minutes, the change in pH (deltapH) in whole saliva differed significantly only between consumption of mineral water and other beverages (P < 0.01).

With regard to dental health, a regular consumption of orange juice or sweetened instant teas should be discouraged.