Table 2.

Characteristics of subjects and sample collection sites.

	Healthy (H)	Periodontitis before non-surgical therapy (P)	Periodontitis after non-surgical therapy (A)	p-value (H vs. P/A)	p-value (P vs. A)
Age	39.31 ± 15.80	51.20 ± 9.99	51.20 ± 9.99	0.02/0.02	NA
Gender (Male/Female)	6/7	8/7	8/7	0.71/0.71	NA
PD (mm) of sites for metabololipidomics	2.85 ± 0.38	6.47 ± 1.13	5.33 ± 1.76	<0.01/<0.01	0.01
PD (mm) of sites for qRT-PCR	2.85 ± 0.38	5.87 ± 1.13	4.13 ± 1.51	<0.01/0.01	<0.01

PD, probing depth; NA, not available due to the subjects are the same in the P and A groups; p-values were calculated using Student's t-test, paired t-test or Chi-squared test.