Table 3. GCF volume and levels of IL-4, IL-10, IL-11, and IL-13 in the study groups at baseline and at the 3-month follow-up.

Parameters	Baseline		3-month of follow-up
	Individual using electronic-cigarettes	Non-smokers	Individual using electronic-cigarettes	Non-smokers
GCF volume (µL)	1.65±0.37a)	1.74±0.41b)	0.66±0.14c)	0.18±0.09
IL-4 (pg/µL)	0.16±0.12a)	0.15±0.13b)	0.71±0.25c)	1.52±0.18
IL-9 (pg/µL)	0.33±0.2a)	0.5±0.12b)	1.7±0.21c)	4.21±0.3
IL-10 (pg/µL)	1.11±0.08a)	1.34±0.15b)	3.15±0.5c)	6.63±0.4
IL-13 (pg/µL)	0.85±0.16a)	0.74±0.12b)	2.26±0.21c)	4.63±0.47

Data are shown as mean±standard deviation.

GCF: gingival crevicular fluid, IL: interleukin.

^a)Compared with electronic-cigarette users at 3-month of follow-up (P<0.05); ^b)Compared with non-smokers at 3-month of follow-up (P<0.05); ^c)Compared with non-smokers (P<0.05).