Cavities and gum diseases are contagious

Cavities (caries) in teeth are bacterial infections and are caused predominantly by a bacterium named Streptococcus mutans. Studies clearly demonstrate that these bacteria necessary for caries initiation and progression can be present in infants’ mouths shortly after the eruption of their first milk teeth.

The micro-organisms responsible for dental caries can be transmitted from one individual to another. Vertical transmission is the transmission of microbes from caregiver to the child and horizontal transmission is the transmission of microorganisms among children of similar age groups (siblings or in school/ nursery).

Several studies have indicated that the transmission of S. mutans to human infants is usually from their mothers as mother is usually the significant adult caring for the child.

A mother with high numbers of S. mutans bacteria in her saliva is a source for infection in the close vicinity of the child. If she, for example, uses her own spoon to feed the child, she may introduce, each time, several hundreds of microbes into the mouth of the child. This is more than 100 times the number that a low infected mother will do. If she at the same time feeds the child with a sucrose-containing dish, she will fulfill another requirement for implantation of these bacteria. Objects such as glasses and forks, which the mother had had in her mouth, may harbor S. mutans for several hours. (Nursing caries: a comprehensive review; Louis W. Ripa. Pediatric Dentistry: December, 1988 ~ Volume 10, Number 4)

Children are also in contact with other children in nurseries or schools or at home for a significant amount of time, which may be another route for the horizontal transmission of microorganisms.

Similarly, micro-organisms which cause gum diseases can also be transmitted from mothers/fathers/care takers to children. Hence, it is essential that caretakers should have optimum oral hygiene to minimise the risk of cavities in children.