When we talk about cavities there are three things that are required. There needs to be a tooth, bacteria and a food source for the bacteria. Let’s focus on the bacteria part of that equation. When we are born, there is virtually no bacteria present in the mouth. Bacteria are “given” to us by what is called vertical transmission from our primary caregiver. That means that the person who attends to our needs most, has the most contact with us and transfers bacteria from their mouth to ours. Examples of how the bacteria are transferred are kissing, sharing eating utensils, cleansing off pacifiers by sucking on them, etc. Therefore, we always look at the primary caregiver’s decay history when assigning risk to our patients (that’s a discussion for a different day).
There is lots of bacteria that are present in the mouth. Some of it is good and some of it is bad. When we have an overload of bad bacteria, it puts us at greater risk for getting cavities. The bacteria in our mouth attach to the teeth and create a biofilm. It is essentially a tangle of proteins and saccharides that create a web the bacteria hide in. This creates a way for the bacteria to adhere to the tooth, and also protects them from things that may want to kill them. When we have a normal balance in our body of good and bad, the pH (or acid content) is neutral leaning toward a high or basic number. When we get out of balance the pH drops and the acid content goes up. The issue this creates is that the bad bacteria, when they feed on things we put in our mouth, create almost 100x more acid that the good bacteria. The good bacteria are not able to live in these conditions and eventually die. This allows the bad bacteria to flourish, growing in numbers and keeping the pH acidic. Eventually, you will move toward having a biofilm that is so acidic the good bacteria will not be able to survive. This unbalance creates a perfect environment for decay. The aim of therapy is to reduce the number of bad bacteria and raise the pH so that the good bacteria can come back in and create balance, and by doing so reducing the risk of getting cavities.
Dr. Boyd Simkins, DDS