You’re now seeing a dentist who’s focused on caries prevention instead of just caries management. Your dental care team reviews your caries risk assessment with you at every visit, working closely with you to achieve your goal—actively preventing cavities from beginning in the first place instead of just reacting to cavities that have already emerged. Of course, during these conversations on optimizing your oral health, your dentist is counseling you on how to manage your biofilm, explaining that it is a major factor in caries formation. All this has lead you to wonder–how did I develop biofilm in the first place, and what causes biofilm on teeth to grow?
You may be wondering what biofilm is to begin with. Simply put, biofilm is the collection of single-celled organisms that live together in a group structure. The name has two parts— “bio” because it is made up of living creatures and “film” referring to the thin, clinging shape/structure. The structure is called an extracellular matrix; it allows the single cell organisms to share resources and act more like a larger, multi-celled organism. Biofilm can be made up of a single type of bacteria or of a few types of bacteria, and it can include single cell organisms like yeast. Bacteria in biofilms behave differently than bacteria remaining single agents.
Now that we understand what biofilm is, let’s talk about where it come from…
Biofilm at the Beginning
Biofilm is not just something that appears in older children and adults. Babies develop biofilm quickly as they develop teeth. Well-meaning mothers who don’t want to put a dirty pacifier back in baby’s mouth and wash it off by popping it in their own mouths or moms who share a spoon with baby quickly introduce the bacteria from their oral biofilm into the baby’s mouth, allowing it to establish a biofilm there. Even before teeth appear, biofilm starts to grow on the newborn baby’s gums. A study out of Israel found evidence that infants start to have measurable levels of oral bacteria in the first 48 hours after birth, and that biofilm closely matches the bacterial composition of the infant’s mother’s biofilm.
Biofilms, once removed, return quickly. It only takes 24 hours after a thorough cleaning for biofilm to regrow. That’s why you can’t just physically remove a biofilm and be done with it; you have to manage your biofilm. It’s important to remember that not all biofilms are bad. It’s possible to have a biofilm that is healthy and does not cause caries disease. Some 20 species of bacteria are closely associated with caries and periodontal disease out of hundreds of microorganisms that can live inside your mouth. The goal is to manage your biofilm to keep it healthy, not eliminate any biofilm completely.
Why Does Biofilm Grow?
Simply, because it eats. Your biofilm eats what and when you eat. Bacteria (and other single celled organisms) thrive on the sugars, natural and added, that are in our food. The more often you eat or drink anything other than plain water, the more often you feed your biofilm. The more sugars in your food and beverages, the more readily the bacteria in the biofilm can use your food for their food.
pH also helps determine how easily certain bacteria in biofilm grow. The bacteria that form dental plaque, a biofilm closely associated with cavity formation and gum disease, thrive in low pH environments. Your oral pH drops each time you eat and drink (other than plain water). Saliva in your mouth can help raise oral pH levels back to safe levels if time between eating and drinking is long enough. Frequent sipping and snacking make biofilms overgrow, leading to more cavity danger. If you must eat frequently, consider xylitol gum or high pH rinses to help raise your pH more quickly.
Biofilm exists in the mouth from early days of life and on teeth from the earliest days in which we have teeth. It’s a constantly growing group of bacteria living together to share resources. Living as a group makes the bacteria much harder to kill. It lives on the food you eat in the acidic conditions that emerge once you begin eating or drinking. Managing your biofilm is a lifelong job that helps lessen cavity risk when done properly.