Table 4.

Differences between marginal bone loss for gender (females/males), periodontitis (periodontal vs. non-periodontal) and smoking (smokers vs. non-smokers)

Year	Site	Gender		History of periodontitis		Smoking		Age
		Mean (SD)	P-valuea	Mean (SD)	P-valuea	Mean (SD)	P-valuea	Mean years	P-valueb
1 year	Mesial	0.6 (0.13)	0.22	0.42 (0.19)	0.009	0.45 (0.38)	0.001	0.32	0.008
	Distal	0.07 (0.15)	0.28	0.38 (0.22)	0.022	0.51 (0.42)	0.004	0.28	0.009
2 years	Mesial	0.12 (0.15)	0.31	0.44 (0.23)	0.015	0.47 (0.48)	0.001	0.3	0.008
	Distal	0.14 (0.16)	0.37	0.41 (0.31)	0.014	0.52 (0.32)	0.007	0.32	0.009
3 years	Mesial	0.18(0.25)	0.31	0.4 (0.33)	0.006	0.45 (0.33)	0.012	0.36	0.003
	Distal	0.19 (0.36)	0.38	0.38 (0.31)	0.015	0.55 (0.42)	0.013	0.38	0.006
4 years	Mesial	0.2 (0.25)	0.41	0.37 (0.35)	0.016	0.5 (0.29)	0.009	0.33	0.005
	Distal	0.19 (0.36)	0.35	0.39 (0.41)	0.008	0.51 (0.32)	0.013	0.31	0.002
5 years	Mesial	0.21 (0.22)	0.36	0.34 (0.45)	0.002	0.47 (0.39)	0.003	0.34	0.007
	Distal	0.22 (0.26)	0.48	0.33 (0.51)	0.003	0.49 (0.42)	0.008	0.35	0.009

^aIndependent samples t-test P-values.

^bPearson correlation coefficients for age.

SD = standard deviation.