The article describes oral bacteria that love sugar and create acids that damage tooth enamel and lead to tooth decay. Arginine is presented in the article as a natural amino acid that can act against these bacteria. In a clinical trial, it was found that plaque treated with arginine remained less acidic. The coating treated in this way was structurally less harmful to the teeth. The biofilm after the use of arginine supported a greater proportion of beneficial bacteria. These changes made biofilms less aggressive to teeth after exposure to sugar. The results of the trial show that arginine can be a natural addition to strategies to prevent tooth decay even before it occurs.