Table 1.

Characteristics of the subjects.

Variables	Items	N
Gender	Male Female	19 14
Age (year)	≤39 40–49 50–59 ≥60	6 7 14 6
Periodontal disease	Yes No	21 12
Gingival bleeding status	High Low	25 8
Systemic disease	Yes No	4 29
Total		33