Caries is the destructive process of the tooth caused by bacteria. Is an infectious disease. If the tooth is destroyed by another cause it is no longer called caries (there are other destructive processes such as chemical erosions, physical wear or fractures). In addition, tooth decay is contagious, it can be passed from one person to another, in different ways.
Cavity-initiating bacteria (Streptococcus mutans)live in tooth enamel. When there are no erupted teeth, these germs are not in the mouth, and we are not born with them because they have nowhere to attach themselves and they do not survive until they find where.
This means that at the very moment of eruption, a tooth can be contaminated by them. They live in the mouths of others. It is a bacteria that we all have, but in people with cavities, with open cavities, with little holes in which these bacteria have made their home, there are far more germs.
Cavities appear most often in children whose mother or primary caregiver has or has had at least one active (unfilled) cavity in the past year. Genetic studies have shown that 60% of streptococci come from the mother, the remaining 40% are from the father, grandparents, caregivers and siblings and playmates.
Newly erupted teeth are the weakest and the ones that are affected before, since they are not yet completely mineralized, and if germs adhere at that very delicate moment and are not removed by brushing, they will cause cavities more frequently.
The bacteria are transmitted by direct physical contact:
- By blowing the soup into the spoon.
- When giving kisses on the baby's mouth. That does not mean that you should not kiss. Kisses are the food of the soul, we must kiss our children ... but with a clean mouth.
- When cleaning teats with our own saliva. Cleaning the nipples of bottles and pacifiers is a controversial measure: Swedish studies highlight that it is a way to immunize children and prevent allergies. But Swedish lifestyles are very different, and they go to the dentist much more frequently and take more account of hygienic measures and the use of fluoride to prevent cavities. Swedish adults have far less cavities than Spanish adults.
In any case we know that tooth decay is an infectious disease, but it is multifactorial, that is, many other variables intervene in its beginning and development, and the microbes are just one more. Bacteria are transmitted, they are contagious, but the rest of the factors are related to the way of life (hygiene and eating habits), with health conditions (certain diseases are more predisposed to having cavities, either by themselves or as side effect of the medication to treat them) or with individual predisposing factors (formation of enamel in intrauterine life, more or less retentive dental anatomy).
Preventing its appearance is possible. The annual dental check-up for parents is an effective measure to know the level of risk of cavities of their children.
You can read more articles similar to Childhood cavities, are they contagious?, in the On-Site Dental Care category.