Comparative assessment of the effect of raw bovine milk, packaged full cream milk, packaged skimmed milk and infant formula on streptococcus mutans biofilm formation

Background: Dental caries is one of the most common chronic diseases of early childhood and is considered as a multi-factorial infectious and transmissible disease. Streptococcus mutans is the major etiological agent of early childhood caries in children. The caries forming activity of S. mutans on teeth are carried out through the formation of dental biofilm containing S. mutans and subsequent production of lactic acid. Milk is a significant part of the human diet. For infants, it is the sole source of vital nutrients for the first six months of its life. An extensively used nutritional supplement for feeding babies and children are infant formulas. Objectives: This study investigated the effect of four different types of milk i.e., raw bovine milk, packaged full fat or whole milk, packaged skimmed milk and infant formula on biofilm formation in the presence of Streptococcus mutans. Methods: A 24-hour culture of S. mutans was treated with various concentrations of the milks and infant formula diluted in bacteriological media. The biofilms were washed, fixed, and stained with crystal violet. The absorbance was measured to evaluate biofilm growth and total absorbance. Results: Biofilm formation occurred in all the four experimental groups and was statistically significant when compared with the control group. Between the groups, the highest biofilm formation was observed in packaged skimmed milk and the least in bovine milk at all dilutions. Conclusion: Bovine milk is least cariogenic of all the experimental groups while packaged skimmed milk is the most cariogenic.