➡️ It is the change in dental plaque ecology that leads to caries lesion development. Whenever there are non-shedding surfaces, bacterial cells will attach to saliva film called the pellicle; the bacterial cells start to multiply to form a microcolony. If left undisturbed the growth continues, resulting in a mature type of biofilm within a week. Different types of acids are created as a result of biofilm metabolism, which causes a shift in oral pH under the critical level. This reduction in the pH level will influence the chemical composition of the tooth surface. The cumulative result of many pH fluctuations over a long period of time is the loss of calcium and phosphate, which makes the enamel surface seem porous (which can be detected clinically as a white spot lesion). Thus, the caries lesion is a result of an imbalance in the equilibrium between tooth mineral loss and biofilm fluid.

Source: https://www.amhsr.org/articles/microbiology-of-dental-caries-a-literature-review-5239.html

Shafer’sTextbook Of Oral Pathology