Effects of Electronic Cigarettes on Oral Cavity: A Systematic Review

The increase in the use of electronic cigarettes (e-cigs) in young people and the lack of knowledge of the health effects of smoking in the short and long term are worrying. Although the oral cavity is the first to interact directly with the e-cig aerosol, studies on potential oral cavity lesions are still limited and there is some controversy about safety.

To perform a systematic review to evaluate the adverse effects of e-cigs on oral health.

The research was conducted using Cochrane Library, Embase, PubMed, and Web of Science. The research was limited to articles in English, Portuguese, and Spanish, published between January 2003 and November 2018. The research question was formulated according to the population, intervention, comparison, outcome (PICO) strategy. The quality of the methodology of each study was evaluated following the guidelines described in the Risk Of Bias In Non-randomized Studies - of Interventions (ROBINS-I) tool.

The initial search resulted in 432 articles, of which only eight were included for analysis. Periodontal and peri-implant clinical and radiographic parameters (plaque index, clinical attachment loss, probing depth, peri-implant bone loss, and radiographic bone level) are worse, and proinflammatory cytokine levels are higher among electronic and conventional cigarette smokers than among nonsmokers. Bleeding on probing was higher in nonsmokers than in conventional cigarette smokers and e-cig users. Nine different lesions of the oral mucosa were detected, with nicotinic stomatitis, hairy tongue, and angular cheilitis being more prevalent in e-cig consumers.

The results suggest that e-cigs are less harmful than conventional cigarettes. However, there is also a greater susceptibility of e-cig consumers to developing alterations in oral biological tissues than ex-smokers or nonsmokers. There is still a clear need for the development of new studies.