Table 1.

Studies collected for qualitative synthesis.

Number	Author (Year of Publication)	Full Title	Summary and Conclusions
1	Javed et al. (2017) [16]	Comparison of periodontal parameters and self-perceived oral symptoms among cigarettes smokers, individuals vaping electronic cigarettes, and never-smokers	The study compared periodontal parameters and self-perceived oral symptoms between cigarettes smokers, individuals using e-cigarettes, and non-smokers. The study concluded that the periodontal inflammation and self-perceived oral symptoms were poorer among cigarette smokers than among vaping individuals.
2	Ghazali et al. (2018) [17]	Oral health of smokers and e-cigarette users: A case-control study	The study compares the oral health of cigarette, e-cigarette, and vape smokers and non-smokers. The study concluded that e-cigarettes have potentially detrimental effects on oral health.
3	Ye et al. (2020) [18]	Inflammatory biomarkers and growth factors in saliva and gingival crevicular fluid of e-cigarette users, cigarette smokers, and dual smokers: A pilot study	The study was on inflammatory biomarkers and growth factors in saliva and crevicular fluid of e-cigarette users, cigarette smokers, and both. In conclusion, smoking/vaping produces significant effects on oral health.
4	Jeong et al. (2020) [19]	Associations of electronic and conventional cigarette use with periodontal disease in South Korean adults	The study examines the associations of e-cigarette and conventional cigarette use with periodontal disease in South Korean adults. They concluded that smoking and vaping produce incremented rates of periodontal disease.
5	Velmulapalli et al. (2021) [20]	Association between vaping and untreated caries A cross-sectional study of National Health and Nutrition Examination Survey 2017–2018 data	The study examines the relationship between vaping and the presence of untreated cavities. In conclusion, both vaping and dual smoking are associated with an increased occurrence of untreated caries.
6	Irusa et al. (2022) [21]	A comparison of the caries risk between patients who use vapes or electronic cigarettes and those who do not: A cross-sectional study	The study deals with the risk of tooth decay associated with vaping. The authors concluded that vaping patients had a higher risk of developing caries.
7	Ramenzoni et al. (2022) [22]	Cytotoxic and inflammatory effects of electronic and traditional cigarettes on oral gingival cells using a novel automated smoking instrument: An in vitro study	The study investigated the effects of e-cigarettes and traditional cigarettes on oral gingival cells using a novel automated smoking instrument. The conclusions drawn stated that e-cig smoking may contribute to the cell damage of oral tissue and tissue inflammation.
8	Xu et al. (2022) [23]	Mechanistic effects of e-liquids on biofilm formation and growth of oral commensal streptococcal communities: Effect of flavoring agents	The mechanistic effects of e-liquids on biofilm formation and the growth of oral commensal streptococcal communities were investigated. The findings of the study indicate that flavored e-liquids have a more detrimental impact on the formation and growth of oral commensal bacteria compared to unflavored e-liquids.