Table 1.

Main information on the included studies - NS

Pub year	Title	Country	NF total	M/F	Age	Standard deviation	PI non-smokers %	Standard deviation	BOP non-smokers %	Standard deviation	PD non-smokers (mm)	Standard deviation
2017	Comparison of periodontal parameters and self-perceived oral symptoms among cigarette smokers, individuals vaping electronic cigarettes, and never-smokers	Saudi Arabia	30	Male	40,7	1,6	21,4	2.8	27.5	3.2	0.57	0.03
2018	Clinical and radiographic periodontal status and whole salivary cotinine. IL-1β and IL-6 levels in cigarette- and waterpipe-smokers and E-cig users	Saudi Arabia	38	Male	41.6	4.5	23	0.004	37.4	6.4	1.4	0.1
2018	Impact of cigarette smoking and vaping on the outcome of full-mouth ultrasonic scaling among patients with gingival inflammation: a prospective study	Saudi Arabia	31	Male	32.6	3.5	46.3	5.2	38.2	6.5	4.2	0.3
2019	Clinical periodontal status and gingival crevicular fluid cytokine profile among cigarette-smokers. electronic-cigarette users and never-smokers	Saudi Arabia	45	124 males/11females	40.6	3.3	18.2	2.45	28.4	1.61	1.6	0.23
2020	Comparison of self-rated oral symptoms and periodontal status among cigarette smokers and individuals using electronic nicotine delivery systems	Saudi Arabia	26	Male	33.5	1.4	4.2	0.5	22.1	3.3	1.5	0.2