Cariogenic potential of sweet flavors in electronic-cigarette liquids

Abstract

BackgroundMost electronic-cigarette liquids contain propylene glycol, glycerin, nicotine and a wide variety of flavors of which many are sweet. Sweet flavors are classified as saccharides, esters, acids or aldehydes. This study investigates changes in cariogenic potential when tooth surfaces are exposed to e-cigarette aerosols generated from well-characterized reference e-liquids with sweet flavors.MethodsReference e-liquids were prepared by combining 20/80 propylene glycol/glycerin (by volume fraction), 10 mg/mL nicotine, and flavors. Aerosols were generated by a Universal Electronic-Cigarette Testing Device (49.2 W, 0.2 Ω). Streptococcus mutans (UA159) were exposed to aerosols on tooth enamel and the biological and physiochemical parameters were measured.ResultsE-cigarette aerosols produced four-fold increase in microbial adhesion to enamel. Exposure to flavored aerosols led to two-fold increase in biofilm formation and up to a 27% decrease in enamel hardness compared to unflavored controls. Esters (ethyl butyrate, hexyl acetate, and triacetin) in e-liquids were associated with consistent bacteria-initiated enamel demineralization, whereas sugar alcohol (ethyl maltol) inhibited S. mutans growth and adhesion. The viscosity of the e-liquid allowed S. mutans to adhere to pits and fissures. Aerosols contained five metals (mean ± standard deviation): calcium (0.409 ± 0.002) mg/L, copper (0.011 ± 0.001) mg/L, iron (0.0051 ± 0.0003) mg/L, magnesium (0.017 ± 0.002) mg/L, and silicon (0.166 ± 0.005) mg/L.ConclusionsThis study systematically evaluated e-cigarette aerosols and found that the aerosols have similar physio-chemical properties as high-sucrose, gelatinous candies and acidic drinks. Our data suggest that the combination of the viscosity of e-liquids and some classes of chemicals in sweet flavors may increase the risk of cariogenic potential. Clinical investigation is warranted to confirm the data shown here.

Potential oral health effects of e‐cigarettes and vaping: A review and case reports

“…There are currently over 10 000 commercially available e‐liquid formulations 7 (Table 1). These formulations basically have three components: a base, nicotine, and flavors.…”

“…The sweet taste of e‐liquids is provided by the inclusion of sucrose or sucralose and the sweet fragrance is created by ethyl maltol. in vitro studies have shown that some of these flavors significantly promote increased biofilm formation and enamel demineralization compared to a base/nicotine control, when used in vaping devices 7 . It is believed that the sweet flavors have been added to e‐liquids to make them especially attractive to young people.…”

“…Scant research has been conducted into the actual cariogenic potential of vaping. A few anecdotal cases of vaping‐related rampant caries have been reported and limited in vitro studies have been conducted 7,11 …”

A thematic analysis of smokers’ and non-smokers’ accounts of E-cigarettes

“…One study has found that EC aerosols have similar chemical properties to high-sucrose, gelatinous and acidic drinks (Kim et al, 2018).…”

Hidden sugars and vaping

“…Fewer than 50% of cultures from actinomyces-related infections manage to isolate a species; as a result many diagnoses rely on histopathological visualisation of actinomyces over microbiological isolation. 1 A fit and healthy 33-year-old male attended our oral surgery unit with a history of tightness in his left jaw and no other symptoms.…”