Objective: to evaluate the effect of dairy products on streptococcus mutans (SM) and lactobacilli (LB) in saliva on group of Egyptian children. Material and Methods: One hundred and twenty Egyptian children from both sexes were included in
this study, their age ranged from 4-12 years old. These children were equally divided into 3 groups, each group consisted of 40 children. First group (group A) was instructed to drink plain cow's milk, second group (group B) was instructed to drink milk plus sugar and third group (group C) was instructed to drink milk plus honey. Three saliva samples were collected from each child, one before drinking the beverage (S1) then immediately after drinking (S2) and finally one hour after drinking the beverage (S3) by spitting in a sterile plastic container, then submitted to the Culture and Sensitivity Unit at The Regional center for Mycology and Biotechnology at Al-Azhar University to evaluate the salivary concentration on SM and LB for each subject. Results: The use of plain milk resulted in decrease in the mean value of SM immediately
after drinking then subsequently showed a slight increase after one hour. And LB mean value increased immediately after beverage, then subsequently showed a significant increase after one hour. The use of milk plus sugar resulted in significant increase in mean value of SM immediately and one hour after beverage. And the mean value of
LB significantly increased immediately and one hour after beverage. The use of milk plus honey resulted in significant decrease in the mean value of SM one hour after beverage .And the mean value of LB significantly decreased immediately and one hour after beverage. Conclusion: the results revealed that, Milk and dairy products have a low cariogenic potential. Adding sugar makes whole milk as cariogenic as a sucrose solution. Natural honey had an antibacterial activity on SM and LB bacteria.