Table 1 The characteristics of the included studies

Kiran et al.

2005

Turkey

44

22

22

Control: delayed treatment Tx1: oral hygiene+SRP

52.82 (12.27) 36

55.95 (11.21) 45

7.0 (0.72)

7.31 (0.74)

3

RCT Single centre

Blinding of assessor

Chen et al.

2012

China

134

44

45

45

Control: no treatment Tx1: SRP Tx2: supragingival prophylaxis

63.2 (8.51) 41.5

59.86 (9.48) 54.8

57.91 (11.35) 60.5

7.25 (1.49)

7.31 (1.23)

7.29 (1.55)

6

RCT Single centre

Koromantzos et al.

2012

Greece

60

30

30

Control:supragingival cleaning Tx:SRP in two sessions

59.42(9.8) 56.7

59.62(7.95) 53.3

7.59(0.66)

7.87(0.74)

3 and 6 months

RCT Single centre

Blinding of assessor

Moeintaghavi et al.

2012

Iran

40

18

22

Control: delayed treatment Tx1: SRP

53.5(9.51) 61.1

56.27(10.52) 40.9

Overall 50.29(3)

8.72 (2.22)

8.15 (1.18)

3

RCT Single centre Blinding of assessor

Singh et al.

2008

India

45

15

15

15

Control:no treatment Tx1:SRP Tx2: SRP+systemic doxycycline

59.3(10.8) 56.3

52.8(10.36) 48.8

8.08(0.78)

7.93(0.78)

8.33(0.72)

3

RCT Single centre

Zhang et al.

2013

China

71

22

49

Control:no treatment Tx:SRP

62.7(10.7) 42.9

60.4(9.77) 45.5

7.38(1.30)

7.68(1.22)

3 and 6 months

RCT Single centre Blinding of assessor

Engebretson et al.

2013

USA

514

257

257

Control:no treatment Tx:SRP+mouthwash

57.9(9.6) 42.1

56.7(10.5) 45.6

7.78(0.60)

7.84(0.65)

3 and 6 months

RCT Multicenter Blinding of assessor

Gay IC et al.

2014

USA

126

66

60

Control:oral hygiene instruction Tx1: scaling +SRP

41.7(10.2) 58.3

45.5(9.0) 54.6

8.4(2.0)

9.0(2.3)

3

RCT Single centre

Raman RP et al.

2014

Malaysia

32

17

15

Control:oral hygiene instruction Tx1: scaling +SRP

73.3( 9.9) 26.7

52.9(6.2) 47.1

7.6 (1.5)

7.8 (1.5)

3

RCT Single centre