Table 4.

Correlations of age, number of teeth, elastase and MMP-9 concentrations in the control group and the PD ≥ 6 mm and PD < 6 mm groups

Group			Age	No of teeth	Elastase	MMP-9
Control	Age	Correlation coefficient	1	–.137	–.050	.550
		p		.656	.870	.051
		N	13	13	13	13
	No of teeth	Correlation coefficient	–.137	1	.259	.019
		p	.656		.393	.950
		N	13	13	13	13
	Elastase	Correlation coefficient	–.050	.259	1	.476
		p	.870	.393		.100
		N	13	13	13	13
	MMP-9	Correlation coefficient	.550	.019	.476	1
		p	.051	.950	.100
		N	13	13	13	13
PD < 6	Age	Correlation coefficient	1	–.763(**)	–.211	–.304
		p		.001	.432	.253
		N	16	16	16	16
	No of teeth	Correlation coefficient	–.763(**)	1	.242	.330
		p	.001		.367	.212
		N	16	16	16	16
	Elastase	Correlation coefficient	–.211	.242	1	.201
		p	.432	.367		.456
		N	16	16	16	16
	MMP-9	Correlation coefficient	–.304	.330	.201	1
		p	.253	.212	.456
		N	16	16	16	16
PD ≥ 6	Age	Correlation coefficient	1	–.624(**)	–.288	–.297
		p		.010	.280	.265
		N	16	16	16	16
	No of teeth	Correlation coefficient	–.624(**)	1	.491	.411
		p	.010		.054	.114
		N	16	16	16	16
	Elastase	Correlation coefficient	–.288	.491	1	.854(**)
		p	.280	.054		.000
		N	16	16	16	16
	MMP-9	Correlation coefficient	–.297	.411	.854(**)	1
		p	.265	.114	.000
		N	16	16	16	16

*Correlation is significant at 0.01 level (two-way)