Table 1.

Clinical characteristic of study groups

	Current smokers	Former smokers	Never smokers	p value
Subjects n	18	18	20
Age	31 (26–37)	32 (25–43)	34 (29.5–37)	0.871
Female	4/17 (23.5%)	7/17 (41.2%)	10/19 (52.6%)	0.202
Exhaled CO	15 (11–14.9)	3 (3–4)	3 (2–4)	< 0.0001
n. Cigarette/day	15 (10–15)	//	//	NA
Pack/years	9.6	4.7	//	NA
Year non-smoking	//	2 (1.5–9)	//	NA
Toothbrushing frequency/daily	2 (1.5–3)	2 (2–3)	2 (2–2.25)	0.454
Mouth washing frequency/daily	0 (0–0)	0 (0–0)	0 (0–2)	0.008
Dental flossing frequency/weekly	0 (0–1.5)	1 (0–1.5)	1 (0–1.5)	0.791

Data are presented as median (IQR), n/N (%)

CO carbon monoxide