While tooth decay, also known as dental caries, is not contagious in the same way a cold or flu virus is, the bacteria responsible for it can be transmitted from person to person. You cannot “catch” a cavity directly, but you can acquire the specific microorganisms that initiate the decay process. Understanding this distinction is important for preventing the development and spread of this common oral health issue.
The True Cause of Tooth Decay
Tooth decay begins when certain bacteria in the mouth convert sugars from food and drinks into acids. These acids then attack and dissolve the hard outer layer of the tooth, called enamel, leading to cavities. The primary bacteria responsible is Streptococcus mutans, which is naturally present in the human oral cavity.
Streptococcus mutans thrives on sugary and starchy foods, producing lactic acid as a byproduct of their metabolism. This acid demineralizes the tooth enamel, weakening it and making it susceptible to decay. The bacteria, acid, food particles, and saliva combine to form dental plaque, a sticky film that adheres to the teeth. Without proper removal, plaque allows acids to remain in contact with the tooth surface, accelerating the decay process.
Pathways of Bacterial Transmission
The bacteria that cause tooth decay, primarily Streptococcus mutans, can spread from person to person, mainly through saliva. This occurs through activities like kissing, sharing eating utensils, drinking cups, or cleaning a baby’s pacifier with one’s mouth.
Infants and young children are particularly vulnerable to acquiring these bacteria. Babies are born with nearly sterile mouths, so bacteria are often introduced inadvertently from parents or caregivers. Many infants become infected with Streptococcus mutans early in life, emphasizing the importance of oral hygiene practices among all family members, especially those caring for young children.
Preventing Bacterial Spread and Decay
Preventing the spread of decay-causing bacteria and limiting tooth decay involves a combination of good oral hygiene practices and mindful habits. Regular brushing with fluoride toothpaste at least twice a day, and preferably after every meal, helps remove plaque and reduce bacteria. Daily flossing is also important to clean between teeth and below the gumline, areas a toothbrush cannot easily reach. Using a fluoride-containing mouthwash can further help kill bacteria and strengthen enamel.
Limiting the intake of sugary and starchy foods and drinks reduces the food source for decay-causing bacteria. If such foods are consumed, brushing soon afterward or rinsing the mouth with water can help. Avoiding sharing utensils, cups, and other items that come into contact with saliva, especially with infants and young children, is a practical step to prevent bacterial transmission. Regular dental check-ups are also important for early detection and treatment of any decay.