4 things are required:
To attack the enamel, the hardest part of our body, specific bacterial strains and plenty of short-chained carbohydrates must be sitting on the teeth over a period of weeks or months. This process is called demineralization or initial caries. And here comes the lucky part of it: this breakdown is initially reversible.
What to do:
Deep remineralization can currently only be successfully achieved with one method called the Curolox technology.
The tooth is treated with a special peptide (=Curodont Repair) which refills the demineralized areas within the enamel. Caries is stopped, and the enamel regenerates. The treatment takes about 10 minutes, has no side effects, and its effectiveness is well supported by studies.
If the initial caries stays untreated a cavity develops. The tooth usually has to be drilled and filled.
Side note: In Europe, 98% of the population develops caries at some point in their lives. This makes caries by far the most common infectious disease in industrialized countries.