Table 1.

Study characteristics of all included randomized-control trials

Last name of first author, years of publication, country	Total sample size	CG (n)	TG (n)	Total duration of diabetes in CG (years)	Total duration of diabetes in TG (years)	Study duration (months)	Inclusion criteria for CP	Inclusion criteria for T2DM	Intervention
Moeintaghavi A et al., 2012, Iran	40	18	22	NR*	NR*	3	Mild-to-moderate periodontitis	HbA1c levels ≥7%	40 patients with T2DM and CP the treatment group (n=22) received full-mouth scaling and root planning, whereas the control group (n=18) received no periodontal treatment
Gay I et al., 2014, USA	126	60	66	NR*	NR*	4	Localized or generalized severe chronic periodontitis	HbA1c levels ≥6.5%	126 T2DM patients with periodontal disease. The test group (n=66) was treated with scaling and root planning the control group (n=60) received oral hygiene instructions but not any periodontal treatment
Engebretson S et al., 2013, USA	514	257	257	11.3	8.2	6	Moderate to advanced CP defined as CAL and PD of at least >5 mm in 2 or more quadrants of the mouth	HbA1c value 7%-9%	514 T2DM patients with CP. The treatment group (n=257) received SRP+chlorhexidine oral rinse at baseline, and supportive periodontal therapy at three and six months. The control group (n=257) received no treatment for 6 months
Raman RPC et al., 2014, Malaysia	32	17	15	NR*	NR*	3	Moderate-to-severe CP	HbA1c levels ≥7%	32 T2DM patients with periodontal disease. The test group (n=15) was treated with scaling and root planning the control group (n=17) received oral hygiene instructions but not any periodontal treatment
Telgi RL et al., 2013, India	40	20	20	NR*	NR*	3	Mild-to-moderate CP	HbA1c levels ≥7%	60 T2DM patients with periodontal disease. Three groups: Group A (scaling, mouthwash, and brushing), Group B (mouthwash and brushing) and Group C (brushing only). In our meta-analysis we have taken Group A data in test and Group C data in control group
Koromantzos PA et al., 2011, Greece	60	30	30	7.84	4.33	6	Moderate-to-severe CP	HbA1c levels 7%-10%	60 T2DM patients with periodontal disease. The intervention group (n=30) was treated with SRP and the delayed treatment group or control group (n=30) that received periodontal care after 6 months

CG – Control group; TG – Treatment group; CP – Chronic periodontitis; T2DM – Type 2 diabetes mellitus; HbA1c – Glycated hemoglobin; SRP – Scaling and root planning; CAL – Clinical attachment level; NR – Values are not reported in respective included study; n – Number of study subjects; PD – Probing depth