Table 2 Tooth –wise Mean Stain Index Total (Intent-To-Treat Subjects)

N

78

70

60

59

52

50

Baseline

Mean

4.1

4.3

4.2

4.3

4.2

4.4

S.D.

1.6

1.6

1.6

1.6

1.7

1.6

Median

4.3

4.2

4.3

4.3

4.4

4.4

Min,Max

(1.30,7.52)

(0.73,7.77)

(1.30,7.52)

(0.73,7.77)

(1.30,7.52)

(1.31,7.77)

Post

Mean

4.1

4.3

4.0

4.4

4.1

4.4

S.D.

1.6

1.6

1.7

1.7

1.7

1.6

Median

4.1

4.3

4.2

4.6

4.4

4.1

Min,Max

(1.22,7.27)

(0.75,7.73)

(1.02,7.45)

(0.69,7.45)

(1.19,7.11)

(1.17,7.63)

Change

Mean

-0.02

0.05

-0.14

0.12

-0.07

-0.05

S.D.

0.34

0.33

0.46

0.50

0.46

0.60

Median

-0.01

0.05

-0.10

0.09

-0.05

-0.02

Min,Max

(-0.83,0.73)

(-1.13,0.98)

(-1.41,0.97)

(-0.97,1.98)

(-1.41,0.88)

(-1.27,1.30)

Paired t-test

p-value

0.536

0.191

0.018

0.079

0.251

0.588

LsMean

-0.03

0.05

-0.13

0.12

-0.09

-0.05

s.e.

0.04

0.04

0.06

0.06

0.08

0.078

Comparison vs. Microtab

p-value

0.147^a

0.005^a

0.74^a

Difference

-0.08

-0.25

-0.04

s.e.

0.06

0.09

0.11

95% C.I.

[-0.19,0.03]

[-0.43,-0.08]

[-0.25,0.17]