Table 1 Participants’ demographic features and clinical characteristics

Demographics

 Age (mean ± SD) years

65.75 ± 6.33

72.31 ± 8.07

76.03 ± 8.23

0.0000^a,b

/

 Male (%)

10 (31.25)

9 (28.13)

20 (62.50)

0.0083^b,c

/

 Female (%)

22 (68.75)

23 (71.87)

12 (37.50)

/

/

 Education > 6 years (%)

29 (90.63)

30 (93.75)

33 (96.88)

0.5866

/

Marital status

 Unmarried (%)

0 (0)

0 (0)

0 (0)

0.1184

/

 Married (%)

32 (100)

30 (93.75)

28 (87.50)

/

/

 Divorced (%)

0 (0)

0 (0)

0 (0)

/

/

 Widowed (%)

0 (0)

2 (6.25)

4 (12.50)

/

/

Living status

 Living alone (%)

3 (9.37)

1 (3.13)

2 (6.25)

0.1120

/

 Living with spouse (%)

27 (84.38)

24 (75.00)

20 (62.50)

/

/

 Living with children (%)

2 (6.25)

5 (15.62)

4 (12.50)

/

/

 Other (%)

0 (0)

2 (6.25)

6 (18.75)

/

/

Neurological indices

 MoCA (mean ± SD)

27.25 ± 1.50

18.88 ± 5.35

9.56 ± 6.44

0.000^a,b,c

0.000^a,b,c

 MMSE (mean ± SD)

28.34 ± 1.07

24.13 ± 4.29

12.56 ± 6.44

0.000^a,b,c

0.000^a,b,c

 APOE gene test (e4 carrier frequency%)

1 (0)

14/5 (35.71)

8/6 (75.00)

/

/

 AV45 PET (positive rate%)

0 (0)

5/3 (60.00)

8/8 (100.00)

/

/

Periodontal indices

 Number of teeth

25.88 ± 3.25

21.31 ± 6.78

18.47 ± 7.76

0.000^a,b

0.023^b

 PPD (mean ± SD) mm

2.56 ± 0.68

2.65 ± 0.52

3.05 ± 0.83

0.016^b

0.057

 CAL (mean ± SD) mm

3.09 ± 0.95

3.64 ± 0.99

4.61 ± 1.42

0.000^b,c

0.009^b,c

 CAL > 3 mm (mean ± SD) %

35.72 ± 24.52

48.36 ± 24.28

69.44 ± 26.31

0.000^b,c

0.007^b,c

 GI (mean ± SD)

1.67 ± 0.24

1.70 ± 0.22

1.81 ± 0.25

0.048

0.302

 PLI (mean ± SD)

1.84 ± 0.26

2.03 ± 0.31

2.22 ± 0.44

0.000^b

0.013^b

 BOP (mean ± SD) %

48.91 ± 24.21

65.42 ± 19.78

72.18 ± 29.68

0.002^b

0.034^b