Table 2.

Outcomes of studies included in the network meta-analysis

First author, year	Inclusion criteria of chronic periodontitis	Method of HbA1c% determination	Initial HbA1c (%) (T vs. C)	Outcome (ΔHbA1c%) (T vs. C)	Outcome (ΔFPG) (T vs. C)	Follow up (m)	Adverse events (T vs. C)
Singh (2008) [25]	Moderate to advanced periodontitis; at least 30% teeth with PPD ≥ 4 mm	Liquid chromatography method	TA: 8.3 ± 0.7 TB: 7.9 ± 0.7 C: 8.08 ± 0.7	TA: 0.8 ± 0.66 TB: 0.6 ± 0.66 C: -0.02 ± 0.72	TA: 4.16 ± 11.55 TB: 4 ± 14.45	3	No
Gilowski (2012) [26]	Periodontitis; at least four nonadjacent sites with PPD ≥ 4 mm	Turbidimetric inhibition immunoassay	T: 6.7 (6.3–7.0) C: 6.2 (6.0–7.8)	T: 0 ± 0.9 C: 0.1 ± 1.41		3	No
Moeintaghavi (2012) [27]	Mild to moderate periodontitis (American Academy of Periodontology)	Cobas Integra 700 apparatus (Roche Diagnostics, Germany)	T: 8.15 ± 1.18 C: 8.72 ± 2.22	T: 0.74 ± 1.18 C: -0.25 ± 2.05	T: 17.5 ± 48.91 C: -9.78 ± 38.02	3	na
Gaikwad (2013) [28]	Chronic generalized periodontitis	na	T: 8.38 ± 0.89 C: 8.06 ± 1.10	T: 1.38 ± 0.83 C: 0.95 ± 1.05	na	4	No
Pradeep (2013) [29]	Chronic periodontitis; PPD ≥ 5 mm or CAL ≥ 4 mm and vertical bone loss ≥ 3mm on intraoral periapical radiographs	na	T: 6.66 ± 0.11 C: 6.71 ± 0.13	3m: T: 0.02 ± 0.12 C: 0.03 ± 0.13 6m: T: 0.01 ± 0.12 C:0.03 ± 0.13 9m: T: 0.03 ± 0.11 C: 0.05 ± 0.13	na	9	No
Santos (2013) [30]	Generalized chronic periodontitis (Armitage 1999); at least 30% of sites with PPD and CAL ≥ 4 mm	high-performance liquid chromatography	T: 10 ± 2.41 C: 10.4 ± 2.9	3m: T: 0.78 ± 3.5 C: 0.68 ± 2.5 6m: T: 0.19 ± 2.9 C: 0.74 ± 4.1 12m: T: 0.35 ± 3.4 C: 1.4 ± 3.0	3m: T: 5.4 ± 65.09 C: 1.4 ± 77.31 6m: T: 5.5 ± 57.34 C: 15.4 ± 80.06 12m: T: 7.2 ± 72.37 C: 20.6 ± 79.15	12	T: 7, C: 12 reported taste perception change/ dry mouth/ staining
Telgi (2013) [31]	mild to moderate periodontitis; PD: 4 – 5 mm	na	TA: 7.68 ± 0.63 TB: 7.56 ± 0.59 C: 7.74 ± 0.59	TA: 0.58 ± 0.27 TB: 0.25 ± 0.14 C: 0.004 ± 0.12	TA: 2.88 ± 1.07 TB: 1.29 ± 0.53 C: 0.42 ± 0.71	3	na
Macedo (2014) [11]	Chronic periodontitis, at least one site with PPD ≥ 5 mm on each quadrant, two teeth with CAL ≥ 6 mm	automated immunoturbidimetric method	T: 8.6 ± 1.1 C: 8.0 ± 0.93	T: 0.87 ± 0.9 C: 0.41 ± 0.84	na	3	No
Miranda (2014) [32]	the sites with PPD and CAL ≥ 4 mm, a minimum of six teeth with at least one site with PPD and CAL ≥ 5 mm, BOP	high-performance liquid chromatography	T: 8.53 ± 1.56 C: 8.99 ± 1.63	3m: T: -0.07 ± 1.83 C: 0.05 ± 1.67 6m: T: 0.04 ± 1.94 C: -0.08 ± 1.66 12m: T: -0.24 ± 2.54 C: 0.59 ± 1.81	3m: T: 5.46 ±38.30 C: 8.71 ± 40.41 6m: T: 6.19 ±34.01 C: 5.95 ± 45.50 12m:T:1.59± 36.53 C: 6.9 ± 47.09	12	Diarrhea: T: 7, C:3 Headache: T: 4, C: 1 Metallic taste: T: 4, C: 2 Nausea/Vomiting: T: 5, C: 2
Tsalikis (2014) [33]	Moderate or advanced periodontitis; six pockets > 5mm, CAL > 3mm with radiographic bone loss	A1CNow + Multitest HbA1c system	T: 6.70 ± 0.61 C: 6.89 ± 0.60	3m: T: 0.08 ± 0.58 C: -0.07 ± 0.88 6m: T: 0.22 ± 0.67 C: 0.09 ± 0.77	na	6	C: 1 reported Dizziness and difficulty to swallow
Wu (2015) [34]	mean CAL > 1mm (American Academy of Periodontology criteria)	immunoturbidimetry	T: 7.41 ± 0.20 C: 7.39 ± 0.16	3m: T: 0.01 ± 0.19 C: 0.01 ± 0.16 6m: T: 0.32 ± 0.17 C: 0.03 ± 0.17	na	6	na
Koçak (2016) [35]	≥ 8 sites with PPD ≥5mm	na	T: 6.9 ± 0.7 C: 6.5 ± 0.6	T: 0.41 ± 0.19 C: 0.22 ± 0.25	na	3	na
Kumari (2016) [10]	Chronic periodontitis; PPD ≥ 5 mm or CAL ≥ 4 mm, and vertical bone loss ≥ 3 mm on intraoral periapical radiographs	na	T: 6.72 ± 0.13 C: 6.75 ± 0.12	3m: T: 0.04 ± 0.14 C: 0.03 ± 0.13 6m: T: 0.06 ± 0.13 C: 0.04 ± 0.13 9m: T: 0.07 ± 0.13 C: 0.06 ± 0.13	na	9	No
Ramos (2016) [36]	At least one site with PPD ≥ 5 mm on each quadrant and two teeth with CAL ≥ 6 mm	High pressure liquid chromatography	T: 10.6 ± 1.99 C: 9.69 ± 1.68	T: 0.99 ± 1.00 C: 0.76 ± 0.73	na	3	No

CAL clinical attachment loss, PPD probing pocket depth, BOP bleeding on probe, na not avail