Data collection

Experimental group

Control group

Group difference

n (%)

Gestational week

n (%)

Gestational week

（Mann-Whitney）

Mean

SD

Range

Mean

SD

Range

U

z

p

Baseline survey

76 (100)

12.7

2.1

8 - 20

131 (100)

12.8

2.3

817

4858.0

−0.293

0.770

Plaque check #1

59 (77.6)

18.0

2.8

13 - 27

Intermediate survey

56 (73.7)

23.1

2.9

19 - 32

99 (75.6)

23.0

2.1

20 - 29

2666.5

−0.399

0.690

Plaque check #2

49 (64.5)

26.9

2.8

23 - 36

Final survey

47 (61.8)

33.1

2.8

27 - 40

98 (74.8)

34.2

1.7

29 - 40

1657.5

−2.779

0.005

Perfect attendance

46 (60.5)

87 (66.4)