Secondhand smoke and tooth decay

Secondhand smoke and tooth decay

Smoking is bad for your oral health, but did you know that smoking can also cause dental problems for the children subjected to your secondhand smoke? Researchers have solidified the link between exposure to secondhand smoke and a greater number of cavities in early childhood.

Across the globe, cavities in deciduous (baby) teeth are common. In the United States, one in every five children has a cavity in their baby teeth while it’s one in every four children in Japan. The best prevention for cavities in baby teeth is to model and enforce healthy oral habits, including brushing twice daily, flossing, and rinsing with a fluoride mouthwash. Oftentimes, parents focus on restricting sugar intake as an additional measure for preventing cavities. Dentists can also recommend fluoride treatments or sealants for children with deep grooves in their teeth.

New studies, however, indicate that some factors in tooth decay may be out of a child’s control. It’s now known that secondhand smoke plays a role in the development of cavities even long after the secondhand smoke exposure. Cavities come from a number of factors including heredity, biological issues like disease, bacterial flora, and environmental factors such as presence or absence of fluoridated water, and lifestyle. It turns out that exposure to secondhand smoke may be both an environmental and lifestyle factor for children.

Some common causes of cavities in children include cariogenic bacteria, inadequate salivary flow, insufficient exposure to fluoride, and poor oral hygiene. One well-known risk for cavity development is the acquisition of Streptococcus mutans. This form of bacteria produces acids from sugar that is consumed, and these dissolve the hard enamel coating on teeth. The bacteria are usually transmitted from mothers at the highest-risk ages of 19-31 months old.

So how does secondhand smoke contribute to a child’s cavities? Secondhand smoke may cause inflammation of the oral membrane, damage to the salivary gland function, and a decrease in serum vitamin C levels, as well as immune dysfunction. These all contribute to the development of cavities in small children.

Researchers in Japan investigated smoking during pregnancy and exposure to household smoke in infants at 4 months of age as risk factors for cavities in baby teeth. They wanted to know whether maternal smoking during pregnancy and exposure of infants to tobacco smoke at the age of 4 months would increase the risk of caries in deciduous teeth.

The team analyzed data for 76,920 children born between 2004 and 2010, who attended routine health checkups at 0, 4, 9 and 18 months, and at 3 years of age at health care centers in Kobe City, Japan.

Mothers completed questionnaires to provide information about secondhand smoke exposure from pregnancy to 3 years of age and other lifestyle factors, such as dietary habits and oral care. Incidence of caries in deciduous teeth was defined as at least one decayed, missing or filled tooth assessed by qualified dentists. For study participants, there was a 55% prevalence of household smoking and 6.8% showed evidence of tobacco exposure. A total of 12,729 cases of dental caries were identified mostly decayed teeth.

Compared to non-smoking households, children exposed to secondhand smoke at 4 months of age had double the cavity rate as children from non-smoking households at 4 months of age. The effect of maternal smoking during pregnancy was not statistically significant.

The finding that smoking during pregnancy did not affect outcomes in young children to age 3 but secondhand smoke did increase the prevalence of cavities to age 3 speaks of the near-certain link between secondhand smoke and cavities. Smoking around young children doubles their risk of developing cavities by age 3. A smoking cessation program is your family’s best bet for overall wellness, and at least minimizing secondhand smoke exposure is also advised.

In addition to mitigating smoke exposure, it is important for parents to introduce good oral care habits during infancy and toddlerhood so that children develop good oral habits that will last their lifetimes. If you have questions about how to make your household a tooth-friendly zone, contact our Melbourne, Florida dentist office today for tips!


Brazier, Y. (2015, October 22). “Tooth decay risk doubles in children exposed to secondhand smoke.” Medical News Today. Retrieved from