Relevance . Whether it comes under microbial plaque to demineralization of enamel depends on the presence of cariesogenic bacteria that exhibit proteolytic activity in relation to the organic components of the interdigital spaces of enamel, easily digestible carbohydrates that enter the oral cavity when eating, the buffer capacity of saliva, capable of neutralizing the pH of plaque within an hour to neutral values after eating. On the knowledge of these factors is based the strategy of prevention of dental caries, based on nutrition management. Of all the above, the optimal factor of influence on the cariesogenic situation in the oral cavity is the time factor – the frequency of consumption of easily digestible carbohydrates during the day. Eating easily digestible carbohydrates that can be a nutrient medium for the oral microflora is recommended only during Breakfast, lunch and dinner, but not during snacks. Purpose . To determine the value of the time factor to change the qualitative composition of plaque. Materials and methods . In a series of clinical-anamnestic and clinical-laboratory studies studied the material-plaque obtained during the examination of 137 adult young people-students aged 18 to 20 years. Plaque sampling was performed immediately after the determination of its cariesogenicity by colometric method by J. L. Hardwick and E. B. Manlay, and after 60 minutes a clinical micrometer was used to determine the short-chain fatty acids in this plaque. Results. The proposed clinical micrometod for determination of short-chain fatty acids in dental plaque stated an increase in the optical density of smears in persons with high caries resistance with a decrease in the optical density in smears in the presence of a carious process in the oral cavity. The obtained data correlate well with the indicators of cariesogenicity in plaque, which increases with a decrease in the content of short-chain fatty acids. Therefore, the content of short-chain fatty acids and dental plaque caries require an individual approach to oral hygiene in different patients. Conclusion. The optimal factor of influence on the cariesogenic situation in the oral cavity is the time factor - the frequency of consumption of easily digestible carbohydrates during the day. Eating easily digestible carbohydrates that can be a nutrient medium for the oral microflora is recommended only during breakfast, lunch and dinner.