Table 1.

Clinical characteristics of the subgingival sampling sites

Subject group	Baseline			Post-treatment
	PPD (mm)	CAL (mm)	% BOP	PPD (mm)	CAL (mm)	% BOP
Healthya, b	3.1 ± 0.42c	0.5 ± 1.13c	4.8d	N/A	N/A	N/A
Diseased; all sitesa, e	5.7 ± 1.36c	5.4 ± 2.16c	86d	N/A	N/A	N/A
Diseased; pre- and post-treatment sitesf	5.8 ± 1.3g	5.5 ± 1.6	89h	4.9 ± 1.41g	5.1 ± 1.59	21h

PPDperiodontal probing depth, CAL clinical attachment loss, BOP bleeding on probing

^aSingle-site samples from two contralateral teeth of each subject

^bFrom mesiopalatal site of the first molars (N = 42) of 21 subjects

^cp <  0.0001 by Student’s t-test between non-diseased and diseased

^dp <  0.0001 by chi-square test between non-diseased and diseased

^eFrom palatal sites of maxillary molars (N = 90), buccal sites of maxillary molars (N = 4) and palatal sites of maxillary premolars (N = 2) of 48 subjects

^fAmong 48 subjects with periodontitis, 19 subjects were sampled again (from a site sampled before the treatment) at least 4 weeks after nonsurgical periodontal therapy

^gp <  0.0005 by paired Student’s t-test before and after treatment

^hp <  0.0001 by chi-square test before and after treatment