Research into tooth decay by the University of Pittsburgh School of Dental Medicine have found that genetic variations may be the cause of tooth decay.
Two medical journals have been written with the findings of the research, stating that the beta defensin 1 (DEFB1) gene, plays a key role in the first-line immune response against invading germs.
What this means is that some people will have softer tooth enamel than others, due to the specific genetics. The softer the enamel, the easier it is for bacteria to destroy the enamel, leading to cavities. So, because genes are the primary determinant of enamel structure, they have a big effect on whether you get tooth decay
Additionally, research in the Oxford Academic journal also suggests genes influence how well you can taste. And the greater your ability to taste, the less likely your teeth are to decay.