Table 1 Demographics, oral health, and cognition of the study participants

Age (years)

66.0 (63.0, 68.0)

66.0 (63.0, 68.0)

65.0 (63.0, 67.0)

0.382

BMI (kg/m²)

23.1 (20.9, 25.3)

22.4 (20.4, 24.8)

23.3 (21.6, 25.7)

< 0.001

Education (year)

5.0 (0.0, 9.0)

9.0 (6.0, 9.0)

1.0 (0.0, 6.0)

< 0.001

Toothbrushing frequency

0.134

0–1 time daily

404 (59.7)

180 (60.8)

224 (58.8)

2–3 times daily

141 (20.8)

52 (17.6)

89 (23.4)

Missing

132 (19.5)

64 (21.6)

68 (17.9)

Smoking

231 (34.1)

223 (75.3)

8 (2.1)

< 0.001

Alcohol consumption

241 (35.6)

212 (71.6)

29 (7.6)

< 0.001

Hypertension

273 (40.3)

108 (36.5)

165 (43.3)

0.086

Diabetes

70 (10.3)

26 (8.8)

44 (11.6)

0.296

Hyperlipidemia

325 (48.0)

121 (40.9)

204 (53.5)

0.001

MMSE

25 (21, 27)

27 (24, 28)

23 (17, 26)

< 0.001

MoCA

16 (12, 21)

19 (16, 23)

13 (9, 18)

< 0.001

Cognitive group

< 0.001

Normal cognition

435 (64.3)

216 (73.0)

219 (57.5)

MCI

187 (27.6)

75 (25.3)

112 (29.4)

Dementia

55 (8.1)

5 (1.7)

50 (13.1)

DT

2.5 (3.2)

2.0 (2.6)

3.0 (3.4)

< 0.001

MT

5.7 (6.1)

5.3 (5.6)

6.1 (6.5)

0.091

FT^*

0.1 (0.4)

0.1 (0.3)

0.1 (0.5)

0.174

DMFT

8.4 (7.1)

7.3 (6.6)

9.2 (7.4)

< 0.001

DFRoot

0.6 (1.2)

0.6 (1.1)

0.7 (1.3)

0.339

Present tooth number

26.3 (6.1)

26.7 (5.6)

26.0 (6.5)

0.091

CI

0.7 (0.2)

0.7 (0.2)

0.6 (0.2)

< 0.001

GBI

0.4 (0.3)

0.4 (0.3)

0.4 (0.3)

0.591

PD, mm

1.8 (0.6)

1.8 (0.6)

1.8 (0.6)

0.091

CAL, mm

3.2 (1.1)

3.4 (1.2)

3.0 (1.0)

< 0.001

Severity of periodontitis (%)

0.044

No/Mild/Moderate

319 (47.1)

126 (42.6)

193 (50.7)

Severe or edentulous

358 (52.9)

170 (57.4)

188 (49.3)

Restoration of missing teeth (%)

0.434

No missing teeth unrestored

374 (55.2)

158 (53.4)

216 (56.7)

With missing teeth unrestored

303 (44.8)

138 (46.6)

165 (43.3)