Table 1:

Data extraction table for the systematic review

	BMC Research Notes 2011,4:460[22]	Joint Bone Spine 84, (2017);113–114[21]	BMC Research Notes 2017,10:34[23]
Study design	Case-control	Case-control	Case-control
Participant number	160	129	171
Cases: Controls	80:80	43:86	57:57:57
Age	Cases: Controls	Cases: Controls	RA: PD: Control
	Both: 20–60 years	46.5: 46.3	42.9: 42:30.5
Gender	F:M;79%: 75.6%	Not indicated	F:M 9:1
Country of origin	Sudan	Burkina Faso	Sudan
Inclusion criteria	2010-ACR/EULAR criteria for RA	2010-ACR/EULAR criteria for RA	2010-ACR/EULAR criteria for RA
Exclusion criteria	Pregnancy, lactation, smoking, periodontal therapy or antibiotics in the previous three months, or any systemic condition which might have affected the progression of periodontitis, localized or generalized aggressive periodontitis	Diabetes mellitus, pregnancy, antibiotic therapy and smoking	Systemic diseases that can affect periodontal status, smoking, antibiotic therapy with the last 3 months and periodontal treatment with in the last 6 months
Major findings	No association between the drugs used for treatment of rheumatoid arthritis (Non Steroidal Anti-Inflammatory Drugs & Disease Mordifying Anti-Rheumatic Drugs) and the periodontal parameters (plaque index, gingival index, and clinical attachment loss).	Periodontal disease was not significantly associated with Age ≥ 50 years , male gender, Disease duration ≥ 10 years, DAS28 ≥ 3.2, Joint deformities and ACPA	The was a significant difference in all periodontal parameters among the three groups. The periodontal disease group experienced significantly higher values in all clinical periodontal parameters in comparison to the RA and healthy groups (p ≤ 0.001).