Table 4 Effect of the availability of sufficient bone height to place longer implants on bone density, insertion torque, follow-up time and changes in the marginal bone level and the crown-to-implant ratio

Yes (63 implants)

Mean

855

46

27.4

0.17

0.19

2.75

Median

950

50

24.1

0.10

0.14

2.59

Range

60 to 1300

5 to 70

11.1 to 67.0

− 0.90 to 1.50

− 1.50 to 1.10

1.30 to 4.70

Standard deviation

306

15

15.2

0.54

0.48

0.74

No (24 implants)

Mean

531

26

26.7

0.08

− 0.10

2.90

Median

500

25

16.8

− 0.03

0

2.97

Range

200 to 950

5 to 65

14.9 to 67.0

− 0.80 to 0.80

− 1.60 to 0.70

1.90 to 3.90

Standard deviation

159

16

16.2

0.42

0.50

0.57

p-value

0.000^a

0.000^a

0.475^a

0.414^b

0.018^b

0.153^a

Total

Mean

766

40

27.2

0.15

0.11

2.79

Median

800

45

21.0

0.09

0.10

2.80

Range

60 to 1300

5 to 70

11.1 to 67.0

− 0.90 to 1.50

− 1.60 to 1.10

1.30 to 4.70

Standard deviation

309

18

15.4

0.51

0.50

0.69